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People are relying on sleeping pills more than ever to get a good night's rest, but a new study by Scripps Clinic researchers links the medications to a 4.6 times higher risk of death and a significant increase in cancer cases among regular pill users.
The results, published February 27 by the open-access online journal BMJ Open, cast a shadow over a growing segment of the pharmaceutical industry that expanded by 23 percent in the United States from 2006 to 2010 and generated about $2 billion in annual sales.
The possible health hazards
"What our study shows is that sleeping pills are hazardous to your health and might cause death by contributing to the occurrence of cancer, heart disease and other ailments," said author Daniel F. Kripke, MD, of the Viterbi Family Sleep Center at Scripps Health in San Diego.
The research is the first to show that eight of the most commonly used hypnotic drugs were associated with increased hazards of mortality and cancer, including the popularly prescribed medications zolpidem (known by the brand name Ambien) and temazepam (also known as Restoril), Dr. Kripke said. Those drugs had been thought to be safer than older hypnotics because of their shorter duration of action.
Study participants who took sleeping pills were matched with control patients of similar ages, gender and health who received no hypnotics in order to eliminate the possibility that other factors led to the results.
"We tried every practical strategy to make these associations go away, thinking that they could be due to use by people with more health problems, but no matter what we did the associations with higher mortality held," said co-author Robert D. Langer, MD, MPH, of the Jackson Hole Center for Preventive Medicine in Jackson, Wyoming.
Even among patients who were prescribed 1 to 18 sleeping pills per year, the risk of death was 3.6 times higher than among similar participants who did not take the medica-tions. The study looked at patients aged 18 years and older, and found the increased risk in all age groups.
Sleeping pills and cancer
Rates of new cancers were 35 percent higher among patients who were prescribed at least 132 hypnotic doses a year as compared with those who did not take the drugs.
Using data stored in an electronic medical record that has been in place for more than a decade, the researchers obtained information on almost 40,000 patients cared for by a large integrated health system in the northeastern United States.
The study included 10,531 sleeping pill users who were prescribed the medications for an average of 2.5 years and 23,674 control participants who were not prescribed the drugs. Information came from outpatient clinic visits conducted between Jan. 1, 2002, and Sept. 30, 2006.
"It is important to note that our results are based on observational data, so even though we did everything we could to ensure their validity, it's still possible that other factors explain the associations," said co-author Lawrence E. Kline, DO, who is medical director of the Viterbi Family Sleep Center. "We hope our work will spur additional research in this area using information from other populations."
Alternatives to medication
The BMJ Open report should prompt physicians to consider alternatives to hypnotic medications, Dr. Kline said.
Clinicians at the Viterbi Family Sleep Center focus on cognitive therapy that teaches patients to better understand the nature of sleep. For example, some people suffering from insomnia might require less than the eight hours of sleep commonly recommended for each night.
Patients also can benefit from practicing good sleeping habits and relaxation, as well as taking advantage of the body's natural clock, which is driven by the rising and setting of the sun, Dr. Kline said. "Understanding how to use the circadian rhythm is a very powerful tool that doesn't require a prescription," he said.
When insomnia results from emotional problems such as depression, doctors should treat the psychological disorder rather than prescribe sleeping pills that could prove to be harmful, Dr. Kripke said.
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Wednesday, February 29, 2012
Eat Your Broccoli: Sulforaphane Prevents Cancer
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Researchers in the Linus Pauling Institute at Oregon State University have discovered yet another reason why the "sulforaphane"compound in broccoli and other cruciferous vegetables is so good for you -- it provides not just one, but two ways to prevent cancer through the complex mechanism of epigenetics.
Epigenetics, an increasing focus of research around the world, refers not just to our genetic code, but also to the way that diet, toxins and other forces can change which genes get activated, or "expressed." This can play a powerful role in everything from cancer to heart disease and other health issues.
Sulforaphane was identified years ago as one of the most critical compounds that provide much of the health benefits in cruciferous vegetables, and scientists also knew that a mechanism involved was histone deacetylases, or HDACs. This family of enzymes can interfere with the normal function of genes that suppress tumors.
HDAC inhibitors, such as sulforaphane, can help restore proper balance and prevent the development of cancer. This is one of the most promising areas of much cancer research. But the new OSU studies have found a second epigenetic mechanism, DNA methylation, which plays a similar role.
"It appears that DNA methylation and HDAC inhibition, both of which can be influenced by sulforaphane, work in concert with each other to maintain proper cell function," said Emily Ho, an associate professor in the Linus Pauling Institute and the OSU College of Public Health and Human Sciences. "They sort of work as partners and talk to each other."
This one-two punch, Ho said, is important to cell function and the control of cell division -- which, when disrupted, is a hallmark of cancer.
"Cancer is very complex and it's usually not just one thing that has gone wrong," Ho said. "It's increasingly clear that sulforaphane is a real multi-tasker. The more we find out about it, the more benefits it appears to have."
DNA methylation, Ho said, is a normal process of turning off genes, and it helps control what DNA material gets read as part of genetic communication within cells. In cancer that process gets mixed up. And of considerable interest to researchers is that these same disrupted processes appear to play a role in other neurodegenerative diseases, including cardiovascular disease, immune function, neurodegenerative disease and even aging.
The influence of sulforaphane on DNA methylation was explored by examining methylation of the gene cyclinD2.
This research, which was published in the journal Clinical Epigenetics, primarily studied the effect on prostate cancer cells. But the same processes are probably relevant to many other cancers as well, researchers said, including colon and breast cancer.
"With these processes, the key is balance," Ho said. "DNA methylation is a natural process, and when properly controlled is helpful. But when the balance gets mixed up it can cause havoc, and that's where some of these critical nutrients are involved. They help restore the balance."
Sulforaphane is particularly abundant in broccoli, but also found in other cruciferous vegetables such as cauliflower and kale. Both laboratory and clinical studies have shown that higher intake of cruciferous vegetables can aid in cancer prevention.
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Researchers in the Linus Pauling Institute at Oregon State University have discovered yet another reason why the "sulforaphane"compound in broccoli and other cruciferous vegetables is so good for you -- it provides not just one, but two ways to prevent cancer through the complex mechanism of epigenetics.
Epigenetics, an increasing focus of research around the world, refers not just to our genetic code, but also to the way that diet, toxins and other forces can change which genes get activated, or "expressed." This can play a powerful role in everything from cancer to heart disease and other health issues.
Sulforaphane was identified years ago as one of the most critical compounds that provide much of the health benefits in cruciferous vegetables, and scientists also knew that a mechanism involved was histone deacetylases, or HDACs. This family of enzymes can interfere with the normal function of genes that suppress tumors.
HDAC inhibitors, such as sulforaphane, can help restore proper balance and prevent the development of cancer. This is one of the most promising areas of much cancer research. But the new OSU studies have found a second epigenetic mechanism, DNA methylation, which plays a similar role.
"It appears that DNA methylation and HDAC inhibition, both of which can be influenced by sulforaphane, work in concert with each other to maintain proper cell function," said Emily Ho, an associate professor in the Linus Pauling Institute and the OSU College of Public Health and Human Sciences. "They sort of work as partners and talk to each other."
This one-two punch, Ho said, is important to cell function and the control of cell division -- which, when disrupted, is a hallmark of cancer.
"Cancer is very complex and it's usually not just one thing that has gone wrong," Ho said. "It's increasingly clear that sulforaphane is a real multi-tasker. The more we find out about it, the more benefits it appears to have."
DNA methylation, Ho said, is a normal process of turning off genes, and it helps control what DNA material gets read as part of genetic communication within cells. In cancer that process gets mixed up. And of considerable interest to researchers is that these same disrupted processes appear to play a role in other neurodegenerative diseases, including cardiovascular disease, immune function, neurodegenerative disease and even aging.
The influence of sulforaphane on DNA methylation was explored by examining methylation of the gene cyclinD2.
This research, which was published in the journal Clinical Epigenetics, primarily studied the effect on prostate cancer cells. But the same processes are probably relevant to many other cancers as well, researchers said, including colon and breast cancer.
"With these processes, the key is balance," Ho said. "DNA methylation is a natural process, and when properly controlled is helpful. But when the balance gets mixed up it can cause havoc, and that's where some of these critical nutrients are involved. They help restore the balance."
Sulforaphane is particularly abundant in broccoli, but also found in other cruciferous vegetables such as cauliflower and kale. Both laboratory and clinical studies have shown that higher intake of cruciferous vegetables can aid in cancer prevention.
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Tuesday, February 28, 2012
Excess Fat May Be "Protective" in Seniors Over 85
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Surprising TAU research finds obesity can decrease risk of mortality in people over 85 years of age
Obesity is considered the leading preventable cause of death worldwide — until you reach old age, that is. Though obesity increases the risk of an early death, shaving an average of six to seven years off a person's lifespan, Tel Aviv University researchers have found that this trend may reverse itself after the age of 85. In these people, excess fat seems to have a "protective" effect, decreasing the risk of death when compared to those who are considered at a normal body weight.
When we reach a very old age, some of the factors that affect mortality in younger people may no longer be significant, explain Prof. Jiska Cohen-Mansfield and Rotem Perach of the Herczeg Institute on Aging and the Sackler Faculty of Medicine.
Heavier people have lower rates of osteoporosis, which could decrease incidences of falls and subsequent injury. Obesity could also provide excess energy storage in times of trauma or stress, or prolong the period of weight loss caused by a decrease in appetite, a common occurrence as people near death.
This research was recently published in the Journal of Aging Research.
The survival effect
Research has consistently shown that people who are underweight in their old age have a higher mortality risk. But until now, the protective impact of obesity on mortality in this same age group has been unexplored.
The study was based on data collected as part of the Cross Sectional and Longitudinal Aging Study (CALAS), which included 1,349 people between the ages of 75-94. Participants were asked basic questions about their height and weight, age, gender, family, education, socioeconomic status, and smoking history. Two decades after the data was first collected, the researchers completed a mortality analysis on the original sample. During the course of these 20 years, 95 percent of the participants had died, leaving 59 subjects still living.
Obesity continued to be a predictor of death for those aged 75-84, notes Prof. Cohen-Mansfield. But past the age of 85, participants who were in the obese category were not only at lower risk of death than their underweight peers, but also appeared to be less at risk than those who had a normal weight as well.
There is a "selective survival" rate at play, say the researchers. Often, obese people die early in life due to obesity-related illnesses. So those who survive to old age could simply be more resilient. The same principle may be true of other factors, such as smoking.
Life at a cost
Though the findings are surprising, Prof. Cohen-Mansfield points out that obesity only has a protective effect when it comes to mortality. Quality of life, she warns, is another matter. "Though obese people over the age of 85 may be less at risk of death, they may suffer more from obesity-related illnesses," she says. "There are other factors to consider, such as pain, multiple ailments, and mobility."
To read the article, see:
http://www.hindawi.com/journals/jar/2011/765071/
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Surprising TAU research finds obesity can decrease risk of mortality in people over 85 years of age
Obesity is considered the leading preventable cause of death worldwide — until you reach old age, that is. Though obesity increases the risk of an early death, shaving an average of six to seven years off a person's lifespan, Tel Aviv University researchers have found that this trend may reverse itself after the age of 85. In these people, excess fat seems to have a "protective" effect, decreasing the risk of death when compared to those who are considered at a normal body weight.
When we reach a very old age, some of the factors that affect mortality in younger people may no longer be significant, explain Prof. Jiska Cohen-Mansfield and Rotem Perach of the Herczeg Institute on Aging and the Sackler Faculty of Medicine.
Heavier people have lower rates of osteoporosis, which could decrease incidences of falls and subsequent injury. Obesity could also provide excess energy storage in times of trauma or stress, or prolong the period of weight loss caused by a decrease in appetite, a common occurrence as people near death.
This research was recently published in the Journal of Aging Research.
The survival effect
Research has consistently shown that people who are underweight in their old age have a higher mortality risk. But until now, the protective impact of obesity on mortality in this same age group has been unexplored.
The study was based on data collected as part of the Cross Sectional and Longitudinal Aging Study (CALAS), which included 1,349 people between the ages of 75-94. Participants were asked basic questions about their height and weight, age, gender, family, education, socioeconomic status, and smoking history. Two decades after the data was first collected, the researchers completed a mortality analysis on the original sample. During the course of these 20 years, 95 percent of the participants had died, leaving 59 subjects still living.
Obesity continued to be a predictor of death for those aged 75-84, notes Prof. Cohen-Mansfield. But past the age of 85, participants who were in the obese category were not only at lower risk of death than their underweight peers, but also appeared to be less at risk than those who had a normal weight as well.
There is a "selective survival" rate at play, say the researchers. Often, obese people die early in life due to obesity-related illnesses. So those who survive to old age could simply be more resilient. The same principle may be true of other factors, such as smoking.
Life at a cost
Though the findings are surprising, Prof. Cohen-Mansfield points out that obesity only has a protective effect when it comes to mortality. Quality of life, she warns, is another matter. "Though obese people over the age of 85 may be less at risk of death, they may suffer more from obesity-related illnesses," she says. "There are other factors to consider, such as pain, multiple ailments, and mobility."
To read the article, see:
http://www.hindawi.com/journals/jar/2011/765071/
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Monday, February 27, 2012
Low levels of omega-3 fatty acids may cause memory problems
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A diet lacking in omega-3 fatty acids, nutrients commonly found in fish, may cause your brain to age faster and lose some of its memory and thinking abilities, according to a study published in the February 28, 2012, print issue of Neurology®, the medical journal of the American Academy of Neurology. Omega-3 fatty acids include the nutrients called docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).
"People with lower blood levels of omega-3 fatty acids had lower brain volumes that were equivalent to about two years of structural brain aging," said study author Zaldy S. Tan, MD, MPH, of the Easton Center for Alzheimer's Disease Research and the Division of Geriatrics, University of California at Los Angeles.
For the study, 1,575 people with an average age of 67 and free of dementia underwent MRI brain scans. They were also given tests that measured mental function, body mass and the omega-3 fatty acid levels in their red blood cells.
The researchers found that people whose DHA levels were among the bottom 25 percent of the participants had lower brain volume compared to people who had higher DHA levels. Similarly, participants with levels of all omega-3 fatty acids in the bottom 25 percent also scored lower on tests of visual memory and executive function, such as problem solving and multi-tasking and abstract thinking.
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A diet lacking in omega-3 fatty acids, nutrients commonly found in fish, may cause your brain to age faster and lose some of its memory and thinking abilities, according to a study published in the February 28, 2012, print issue of Neurology®, the medical journal of the American Academy of Neurology. Omega-3 fatty acids include the nutrients called docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).
"People with lower blood levels of omega-3 fatty acids had lower brain volumes that were equivalent to about two years of structural brain aging," said study author Zaldy S. Tan, MD, MPH, of the Easton Center for Alzheimer's Disease Research and the Division of Geriatrics, University of California at Los Angeles.
For the study, 1,575 people with an average age of 67 and free of dementia underwent MRI brain scans. They were also given tests that measured mental function, body mass and the omega-3 fatty acid levels in their red blood cells.
The researchers found that people whose DHA levels were among the bottom 25 percent of the participants had lower brain volume compared to people who had higher DHA levels. Similarly, participants with levels of all omega-3 fatty acids in the bottom 25 percent also scored lower on tests of visual memory and executive function, such as problem solving and multi-tasking and abstract thinking.
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Research offers insight to how fructose causes obesity and other illness
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A group of scientists from across the world have come together in a just-published study that provides new insights into how fructose causes obesity and metabolic syndrome, more commonly known as diabetes.
In this study which was performed in lab animals, researchers found that fructose can be metabolized by an enzyme that exists in two forms. One form appears to be responsible for causing how fructose causes fatty liver, obesity, and insulin resistance. The other form may actually protect animals from developing these features in response to sugar. These studies may provide important insights into the cause of the prediabetic condition known as "metabolic syndrome", which currently affects more than one-quarter of adults in the United States.
The study, "Opposing effects of fructokinase C and A isoforms on fructose-induced metabolic syndrome in mice" was published today in the journal Proceedings of the National Academy of Sciences. Richard Johnson, MD, the senior author of the study and Chief of the Division of Renal Diseases and Hypertension at the University of Colorado School of Medicine said the findings are significant because we now have a better understanding of how fructose causes obesity and other illnesses.
"These studies provide new insights into how fructose may contribute to the development of obesity and diabetes. In particular, the identification of contrasting roles for two enzymes that are involved in fructose metabolism was surprising and could be important in understanding why some individuals may be more sensitive to the metabolic effects of fructose than others."
Previous research has shown that fructose intake in added sugars such as sucrose and high fructose corn syrup is strongly linked to the epidemic rise in obesity and nonalcoholic fatty liver disease. Fructose intake also causes features of metabolic syndrome in laboratory animals and humans. It is known to cause visceral (organ) fat accumulation and insulin resistance compared to starch based diets even when calories are kept even.
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A group of scientists from across the world have come together in a just-published study that provides new insights into how fructose causes obesity and metabolic syndrome, more commonly known as diabetes.
In this study which was performed in lab animals, researchers found that fructose can be metabolized by an enzyme that exists in two forms. One form appears to be responsible for causing how fructose causes fatty liver, obesity, and insulin resistance. The other form may actually protect animals from developing these features in response to sugar. These studies may provide important insights into the cause of the prediabetic condition known as "metabolic syndrome", which currently affects more than one-quarter of adults in the United States.
The study, "Opposing effects of fructokinase C and A isoforms on fructose-induced metabolic syndrome in mice" was published today in the journal Proceedings of the National Academy of Sciences. Richard Johnson, MD, the senior author of the study and Chief of the Division of Renal Diseases and Hypertension at the University of Colorado School of Medicine said the findings are significant because we now have a better understanding of how fructose causes obesity and other illnesses.
"These studies provide new insights into how fructose may contribute to the development of obesity and diabetes. In particular, the identification of contrasting roles for two enzymes that are involved in fructose metabolism was surprising and could be important in understanding why some individuals may be more sensitive to the metabolic effects of fructose than others."
Previous research has shown that fructose intake in added sugars such as sucrose and high fructose corn syrup is strongly linked to the epidemic rise in obesity and nonalcoholic fatty liver disease. Fructose intake also causes features of metabolic syndrome in laboratory animals and humans. It is known to cause visceral (organ) fat accumulation and insulin resistance compared to starch based diets even when calories are kept even.
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Friday, February 24, 2012
Citrus Fruits May Help Women Reduce Risk Of Stroke
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Eating citrus fruits, especially oranges and grapefruit, because of the flavonone they contain, may lower women's risk of developing clot-associated or ischemic stroke, according to a new study led by Norwich Medical School of the University of East Anglia in the UK that was published online in Stroke: Journal of the American Heart Association on Thursday.
The researchers wanted to examine more closely how consumption of foods containing different classes of flavonoids affected the risk of stroke.
Flavonoids are a group of compounds found in fruits, vegetables, dark chocolate and red wine.
Study lead author and professor of nutrition at Norwich Medical School, Dr Aedín Cassidy, told the press:
"Studies have shown higher fruit, vegetable and specifically vitamin C intake is associated with reduced stroke risk."
A stroke is where part of the brain shuts down because of loss of blood supply, caused either by a blockage or embolism that stops the blood flow (ischemia), or due to leakage caused by a hemorrhage.
Cassidy said flavonoids are thought to provide some protection against stroke by improving blood vessel function and reducing inflammation, among other things.
For their study, Cassidy and colleagues examined data from the Nurse's Health Study. Based in the US, this is one of the largest and longest running investigations of factors that influence women's health. It started in 1976 and expanded in 1989.
The researchers looked at 14 years of follow-up data completed by 69,622 female participants who every four years had reported their dietary intake, including details of the fruits and vegetables they consumed.
They looked for links between the six major subclasses of flavonoids commonly present in the American diet and risk of ischemic, hemorrhagic and total stroke.
The six major subclasses they examined were: flavonones, anthocyanins, flavon-3-ols, flavonoid polymers, flavonols and flavones.
Since we already know that each subclass has a different biological effect, the researchers did not expect to find any strong beneficial links between total flavonoid consumption and stroke risk.
But they did find a strong link between high consumption of flavonones in citrus fruits and reduced stroke risk: women who consumed the most showed a 19% lower risk of ischemic stroke compared to women who ate the least amounts of flavonones in citrus fruits.
In this study, oranges and orange juice (82%) and grapefruit and grapefruit juice (14%) had the highest amounts of flavonones. But the researchers said if you are looking to increase your intake, then go for the fruit rather than the juice, because the latter tends to be accompanied by high amounts of sugar.
While previous studies have shown links between various foods and protection against both kinds of stroke, and this study further informs the field, the researchers said we still need to get a better understanding about why the link occurs, and that has to come from further research.
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Eating citrus fruits, especially oranges and grapefruit, because of the flavonone they contain, may lower women's risk of developing clot-associated or ischemic stroke, according to a new study led by Norwich Medical School of the University of East Anglia in the UK that was published online in Stroke: Journal of the American Heart Association on Thursday.
The researchers wanted to examine more closely how consumption of foods containing different classes of flavonoids affected the risk of stroke.
Flavonoids are a group of compounds found in fruits, vegetables, dark chocolate and red wine.
Study lead author and professor of nutrition at Norwich Medical School, Dr Aedín Cassidy, told the press:
"Studies have shown higher fruit, vegetable and specifically vitamin C intake is associated with reduced stroke risk."
A stroke is where part of the brain shuts down because of loss of blood supply, caused either by a blockage or embolism that stops the blood flow (ischemia), or due to leakage caused by a hemorrhage.
Cassidy said flavonoids are thought to provide some protection against stroke by improving blood vessel function and reducing inflammation, among other things.
For their study, Cassidy and colleagues examined data from the Nurse's Health Study. Based in the US, this is one of the largest and longest running investigations of factors that influence women's health. It started in 1976 and expanded in 1989.
The researchers looked at 14 years of follow-up data completed by 69,622 female participants who every four years had reported their dietary intake, including details of the fruits and vegetables they consumed.
They looked for links between the six major subclasses of flavonoids commonly present in the American diet and risk of ischemic, hemorrhagic and total stroke.
The six major subclasses they examined were: flavonones, anthocyanins, flavon-3-ols, flavonoid polymers, flavonols and flavones.
Since we already know that each subclass has a different biological effect, the researchers did not expect to find any strong beneficial links between total flavonoid consumption and stroke risk.
But they did find a strong link between high consumption of flavonones in citrus fruits and reduced stroke risk: women who consumed the most showed a 19% lower risk of ischemic stroke compared to women who ate the least amounts of flavonones in citrus fruits.
In this study, oranges and orange juice (82%) and grapefruit and grapefruit juice (14%) had the highest amounts of flavonones. But the researchers said if you are looking to increase your intake, then go for the fruit rather than the juice, because the latter tends to be accompanied by high amounts of sugar.
While previous studies have shown links between various foods and protection against both kinds of stroke, and this study further informs the field, the researchers said we still need to get a better understanding about why the link occurs, and that has to come from further research.
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Wednesday, February 22, 2012
World of Warcraft Boosts Cognitive Functioning In Some Older Adults
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For some older adults, the online video game World of Warcraft (WoW) may provide more than just an opportunity for escapist adventure. Researchers from North Carolina State University have found that playing WoW actually boosted cognitive functioning for older adults – particularly those adults who had scored poorly on cognitive ability tests before playing the game.
“We chose World of Warcraft because it has attributes we felt may produce benefits – it is a cognitively challenging game in a socially interactive environment that presents users with novel situations,” says Dr. Anne McLaughlin, an assistant professor of psychology at NC State and co-author of a paper on the study. “We found there were improvements, but it depended on each participant’s baseline cognitive functioning level.”
Researchers from NC State’s Gains Through Gaming laboratory first tested the cognitive functioning of study participants, aged 60 to 77, to set a baseline. The researchers looked at cognitive abilities including spatial ability, memory and how well participants could focus their attention.
An “experimental” group of study participants then played WoW on their home computers for approximately 14 hours over the course of two weeks, before being re-tested. A “control” group of study participants did not play WoW, but were also re-tested after two weeks.
Comparing the cognitive functioning test scores of participants in the experimental and control groups, the researchers found the group that played WoW saw a much greater increase in cognitive functioning, though the effect varied according to each participant’s baseline score.
“Among participants who scored well on baseline cognitive functioning tests, there was no significant improvement after playing WoW – they were already doing great,” McLaughlin says. “But we saw significant improvement in both spatial ability and focus for participants who scored low on the initial baseline tests.” Pre- and post-game testing showed no change for participants on memory.
“The people who needed it most – those who performed the worst on the initial testing – saw the most improvement,” says Dr. Jason Allaire, an associate professor of psychology at NC State and co-author of a paper on the study.
The paper, “Individual differences in response to cognitive training: Using a multi-modal, attentionally demanding game-based intervention for older adults,” is published online in Computers in Human Behavior. Lead author of the paper is Laura Whitlock, an NC State Ph.D. student. The research was supported by NC State’s College of Humanities and Social Sciences.
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For some older adults, the online video game World of Warcraft (WoW) may provide more than just an opportunity for escapist adventure. Researchers from North Carolina State University have found that playing WoW actually boosted cognitive functioning for older adults – particularly those adults who had scored poorly on cognitive ability tests before playing the game.
“We chose World of Warcraft because it has attributes we felt may produce benefits – it is a cognitively challenging game in a socially interactive environment that presents users with novel situations,” says Dr. Anne McLaughlin, an assistant professor of psychology at NC State and co-author of a paper on the study. “We found there were improvements, but it depended on each participant’s baseline cognitive functioning level.”
Researchers from NC State’s Gains Through Gaming laboratory first tested the cognitive functioning of study participants, aged 60 to 77, to set a baseline. The researchers looked at cognitive abilities including spatial ability, memory and how well participants could focus their attention.
An “experimental” group of study participants then played WoW on their home computers for approximately 14 hours over the course of two weeks, before being re-tested. A “control” group of study participants did not play WoW, but were also re-tested after two weeks.
Comparing the cognitive functioning test scores of participants in the experimental and control groups, the researchers found the group that played WoW saw a much greater increase in cognitive functioning, though the effect varied according to each participant’s baseline score.
“Among participants who scored well on baseline cognitive functioning tests, there was no significant improvement after playing WoW – they were already doing great,” McLaughlin says. “But we saw significant improvement in both spatial ability and focus for participants who scored low on the initial baseline tests.” Pre- and post-game testing showed no change for participants on memory.
“The people who needed it most – those who performed the worst on the initial testing – saw the most improvement,” says Dr. Jason Allaire, an associate professor of psychology at NC State and co-author of a paper on the study.
The paper, “Individual differences in response to cognitive training: Using a multi-modal, attentionally demanding game-based intervention for older adults,” is published online in Computers in Human Behavior. Lead author of the paper is Laura Whitlock, an NC State Ph.D. student. The research was supported by NC State’s College of Humanities and Social Sciences.
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Tuesday, February 21, 2012
Are all carbs bad?
I eat a lot of carbs: fruits, vegetables, beans and whole grains mostly. I need them to feel full. Some of my friends (and my wife) advocate a low carb, high protein diet, but I have chosen to eat very little meat, cheese and eggs for health reasons. If I give up carbs, that pretty much leaves only fish, of which I eat a lot, but that brings its own health issues.
I 'm clearly not going to lose weight on my chosen regimen, but how bad are carbs really?
The same article I quoted on the dangers of fructose was actually mostly about the dangers of carbs:
I've cut out rice (except on sushi), potatoes and white bread (mostly.) I've cut back on pastry (although I need to do even better there.) So how am I doing carb wise? Not bad, according to the Harvard School of Public Health:
They are pretty positive on fruits as well:
Eating whole grain carbs may actually be good for me:
Also:
and specifically:
1. Brown Rice
2. Oatmeal
My conclusion - I will try even harder to avoid refined grains, but not worry at all about consuming high fiber carbs.
I 'm clearly not going to lose weight on my chosen regimen, but how bad are carbs really?
The same article I quoted on the dangers of fructose was actually mostly about the dangers of carbs:
Overconsumption of carbs is the primary driving factor for insulin resistance and type 2 diabetes. Unfortunately, the conventional medical wisdom has unwisely been extolling the virtues of carbohydrates for years, even placing them as the "foundation" of the highly flawed food pyramid.
If you are seeking to lose weight and optimize your health, foods like bread, rice and pasta should comprise very low percentages of your diet. Virtually anyone who bought into these high-carb, low-fat dietary recommendations has likely struggled with their weight and health, wondering what they're doing wrong.
The problem is that overeating carbohydrates can prevent a higher percentage of fats from being used for energy, and lead to an increase in fat production and storage. It also raises your insulin levels, which in short order can cause insulin resistance, followed by diabetes. Insulin resistance is also at the heart of virtually every chronic disease known to modern man.
Your Body Stores Excess Carbs as Fat
Your body has a limited capacity to store excess carbohydrates. This is one of the reasons why elevated blood sugar follows their overconsumption. One of the ways your body avoids dangerously elevated blood sugar is through converting those excess carbohydrates into excess body fat primarily in your belly. The way it works is that any carbohydrates not immediately used by your body are stored in the form of glycogen (a long string of glucose molecules linked together). Your body has two storage sites for glycogen: your liver and your muscles. Once the glycogen levels are filled in both your liver and muscles, excess carbohydrates are converted into fat and stored in your adipose, that is, fatty, tissue.
So, although carbohydrates are "fat-free," this is misleading because excess carbohydrates end up as excess fat. Puffed rice, in fact, is capable of making your blood sweeter than white sugar, due to the fact that it is higher on the glycemic index – all the more reason why refined grains are "hidden sugar," and sugar is in many ways "hidden fat."
But that's not the worst of it. Any meal or snack high in carbohydrates will also generate a rapid rise in blood glucose. To adjust for this rapid rise, your pancreas secretes insulin into your bloodstream, which then lowers your levels of blood glucose. The problem is that insulin is essentially a storage hormone, evolved to put aside excess carbohydrate calories in the form of fat in case of future famine. So the insulin that's stimulated by excess carbohydrates aggressively promotes the accumulation of body fat!
In other words, when you eat too much sugar, bread, pasta, and any other grain products, you're essentially sending a hormonal message, via insulin, to your body that says "store more fat." This is actually a highly beneficial response in certain scenarios such as when calories are very scarce. This provides a major survival advantage -- but for nearly everyone reading this, having insufficient calories is not an issue, so this protective mechanism actually sabotages your health.
Additionally, increased insulin levels also:
* Make it virtually impossible for you to use your own stored body fat for energy.
* Suppress two important hormones: glucagon and growth hormone. Glucagon promotes the burning of fat and sugar. Growth hormone is used for muscle development and building new muscle mass.
* Increases hunger: As blood sugar increases following a carbohydrate meal, insulin rises with the eventual result of lower blood sugar. This results in hunger, often only a couple of hours (or less) after the meal, in a vicious endocrine rollercoaster that takes us from meal to compulsive meal without ever feeling satisfied.
So, all in all, the excess carbohydrates in your diet can not only make you fat, they can make sure you stay fat. Cravings, usually for sweets, are frequently part of this cycle, leading you to resort to snacking, often on more carbohydrates. Not eating can make you feel ravenous shaky, moody and ready to "crash." If the problem is chronic, you never get rid of that extra stored fat, and your energy and overall health is adversely affected.
I've cut out rice (except on sushi), potatoes and white bread (mostly.) I've cut back on pastry (although I need to do even better there.) So how am I doing carb wise? Not bad, according to the Harvard School of Public Health:
Don't be misled by fad diets that make blanket pronouncements on the dangers of carbohydrates. They provide the body with fuel it needs for physical activity and for proper organ function, and they are an important part of a healthy diet. But some kinds of carbohydrates are far better than others.
Choose the best sources of carbohydrates—whole grains (the less processed, the better), vegetables, fruits and beans—since they promote good health by delivering vitamins, minerals, fiber, and a host of important phytonutrients. Skip the easily digested refined carbohydrates from refined grains—white bread, white rice, and the like— as well as pastries.
They are pretty positive on fruits as well:
Eating whole grain carbs may actually be good for me:
Study Confirms Health Benefits of Whole Grains
A diet high in whole grain foods is associated with a significantly lower risk of developing cardiovascular disease, including heart disease and stroke, according to an analysis conducted by researchers at Wake Forest University School of Medicine.
“Consuming an average of 2.5 servings of whole grains each day is associated with a 21 percent lower risk of cardiovascular disease compared to consuming only 0.2 servings,” said Philip Mellen, M.D., lead author and an assistant professor of internal medicine. “These findings suggest that we should redouble our efforts to encourage patients to include more of these foods in their diets.”
These results were published on line in Nutrition, Metabolism & Cardiovascular Diseases and will appear in a future print issue.
The findings are based on an analysis of seven studies involving more than 285,000 people. By combining the data from these seven studies, researchers were able to detect effects that may not have shown up in each individual study. The studies were conducted between 1966 and April 2006.
Mellen said the findings are consistent with earlier research, but that despite abundant evidence about the health benefits of whole grains, intake remains low. A nutrition survey conducted between 1999 and 2000 found that only 8 percent of U.S. adults consumed three or more servings of whole grain per day and that 42 percent of adults ate no whole grains on a given day.
“Many consumers and health professionals are unaware of the health benefits of whole grains,” said Mellen.
A grain is “whole” when the entire grain seed is retained: the bran, germ and the endosperm. The bran and germ components are rich in fiber, vitamins, minerals, antioxidants, and healthy fats. These are the parts removed in the refining process, leaving behind the energy-dense but nutrient-poor endosperm portion of the grain. Examples of whole grain foods include wild rice, popcorn, oatmeal, brown rice, barley, wheat berries and flours such as whole wheat.
In addition to protecting against cardiovascular disease, which accounts for one-third of deaths worldwide, there is evidence that whole grains also project against diabetes and other chronic conditions.
“Years ago, scientists hypothesized that the higher rates of chronic diseases we have in the West, including heart disease, are due, in part, to a diet full of processed foods,” Mellen said. “Subsequent studies have born that out – especially with whole grains. Greater whole grain intake is associated with less obesity, diabetes, high blood pressure, and high cholesterol – major factors that increase the risk for heart disease and stroke.”
According to nutritionists, consumers should look for “100 percent whole grain” on food labels or look for specific types of whole-grain flour as the main ingredient, such as “whole wheat.”
Also:
Cardiovascular Disease
Eating whole instead of refined grains substantially lowers total cholesterol, low-density lipoprotein (LDL, or bad) cholesterol, triglycerides, and insulin levels. Any of these changes would be expected to reduce the risk for cardiovascular disease. In the Harvard-based Nurses' Health Study, women who ate 2 to 3 servings of whole-grain products (mostly bread and breakfast cereals) each day were 30 percent less likely to have a heart attack or die from heart disease over a 10-year period than women who ate less than 1 serving per week (1). A recent meta-analysis of seven major studies showed that cardiovascular disease (heart attack, stroke, or the need for a procedure to bypass or open a clogged artery) was 21 percent less likely in people who ate 2.5 or more servings of whole-grain foods a day compared with those who ate less than 2 servings a week (2).
Type 2 Diabetes
In a study of more than 160,000 women whose health and dietary habits were followed for up to 18 years, those who averaged 2 to 3 servings of whole grains a day were 30 percent less likely to have developed type 2 diabetes than those who rarely ate whole grains (3). When the researchers combined these results with those of several other large studies, they found that eating an extra 2 servings of whole grains a day decreased the risk of type 2 diabetes by 21 percent.
Cancer
The data on cancer are mixed, with some studies showing a protective effect and others showing none (4). A large, five-year study among nearly 500,000 men and women suggests that eating whole grains, but not dietary fiber, offers modest protection against colorectal cancer (5, 6).
Digestive Health
By keeping the stool soft and bulky, the fiber in whole grains helps prevent constipation, a common, costly, and aggravating problem. It also helps prevent diverticular disease (the development of tiny pouches inside the colon that are easily irritated and inflamed) by decreasing pressure in the intestines.
Staying Alive
An intriguing report from the Iowa Women's Health Study linked whole-grain consumption with fewer deaths from noncardiac, noncancer causes. Compared with women who rarely or never ate whole-grain foods, those who had at least two or more servings a day were 30 percent less likely to have died from an inflammation-related condition over a 17-year period (7).
and specifically:
1. Brown Rice
2. Oatmeal
My conclusion - I will try even harder to avoid refined grains, but not worry at all about consuming high fiber carbs.
Monday, February 20, 2012
Fruits and Fructose - Good or Bad?
Ω
I eat a lot of fruit: raisins, grapes, blueberries, apples, strawberries, bananas, orange juice and tomatoes (yes, tomatoes are a fruit.) I always thought they were good for me (well orange juice in great moderation, only to enhance the benefits of green/white tea.)
Lots of research highlights the benefits:
Here are just a few examples:
1. Apples
2. Blueberries
Blueberries Help Build Strong Bones
Blueberries may inhibit development of fat cells
Blueberries: a Cup a Day May Keep Cancer Away
Blueberry’s positive effects on cholesterol
3. Strawberries
Strawberries Boost Red Blood Cells
Strawberries Fight Diabetes and Nervous System Diseases
Strawberries may slow precancerous growth
Strawberries Protect the Stomach from Alcohol
Even the government says fruits are good:
But a recent article sent to me by a reader/friend says quite the opposite:
So what should I do?
Well this article, Fructose: Sweet, But Dangerous, suggests that fruit isn't really so bad:
But this table tells me apples, grapes, and especially raisins, are particularly bad.
My conclusion - I'm going to go right on eating most of my fruits but will cut down on raisins, which I use to sweeten my daily oat meal ( the subject of my next, similar, post).
More on Fructose (Some of it quite contradictory):
Bad
Fructose not only results in a lower level of satiety, it also stimulates the reward system in the brain to a lesser degree than glucose. This may cause excessive consumption accompanied by effects that are a risk to health, report researchers from the University of Basel in a study published in the scientific journal PLOS ONE. Various diseases have been attributed to industrial fructose in sugary drinks and ready meals.
Fruit sugar, or fructose, is a carbohydrate that occurs naturally in fruits and vegetables and is generally harmless in this form. Despite their similar structures, fructose and glucose - that is, pure grape sugar - affect the body very differently: an intake of glucose causes a sharp increase in blood insulin within minutes, whereas fructose stimulates insulin secretion to a limited degree only.
Teams of researchers led by Professor Christoph Beglinger from the University Hospital and Professor Stefan Borgwardt from the Psychiatric University Clinics (UPK Basel) have now taken a more in-depth look at how these two types of sugar affect interactions between the gastrointestinal tract and the brain. Their work was funded by the Swiss National Science Foundation. In their study, the researchers used combined pharmacological and imaging methods such as functional magnetic resonance imaging (MRI).
Brain activity examined
In the placebo-controlled, double-blind study, twelve healthy young men were given either fructose, glucose or a placebo by way of a feeding tube. Blood samples were then taken from the subjects to measure satiety hormones. The subjects were also asked about how satiated they felt, and their brain activity was monitored by MRI while at rest.
The findings of the pilot study were as follows. Unlike glucose, fructose is less effective at creating feelings of satiety and stimulating the reward system in the brain. An analysis of the MRIs in fact showed that the two types of sugar differed greatly in terms of network activation within the hippocampus and amygdala areas of the limbic system, i.e. the regions of the brain that regulate emotions and impulses. Furthermore, in contrast to glucose (which stimulated a strong signal) the levels of satiety hormones in the blood barely or only minimally increased following fructose consumption. The subjective feeling of satiety also tended to be less affected by the consumption of fructose.
The problem of fructose
"The study may provide the first key findings about the lack of satiety and rewarding effects triggered by fructose," state lead authors Dr Bettina Wölnerhanssen and Dr Anne Christin Meyer-Gerspach. The role of the differing insulin levels and other effects will have to be demonstrated in further studies with more test subjects. Research is increasingly finding indications that isolated, industrially manufactured fructose - which is increasingly used in sugary drinks, sweets and ready meals - is problematic for the human body. It is suspected that fructose promotes the development of various disorders such as obesity, diabetes, fatty liver disease and gout.
Fructose powers a vicious circle
'Walk through any supermarket and take a look at the labels on food products, and you'll see that many of them contain fructose, often in the form of sucrose (table sugar)' -- that's how Wilhelm Krek, professor for cell biology at ETH Zurich's Institute for Molecular Health Sciences, summarises the problem with today's nutrition. Prepared foods and soft drinks in particular, but even purportedly healthy fruit juices contain fructose as an artificial additive -- often in high quantities. In recent decades fructose spread throughout the food market, due to a reputation as being less harmful than glucose. In contrast to glucose, fructose barely increases blood glucose levels and insulin secretion. This avoids frequently recurring insulin spikes after any glucose consumption, which are judged harmful. In addition, fructose is sweeter to the taste.
But there's a downside: the liver converts fructose very efficiently into fat. People who consume too much high-fructose food can in time become overweight and develop high blood pressure, dyslipidaemia with fatty liver and insulin resistance -- symptoms that doctors group together under the name metabolic syndrome.
Unchecked growth of the heart muscle
A new paper by Krek and his team member Peter Mirtschink describes a further, more troubling side effect of fructose. The researchers have discovered a previously unknown molecular mechanism that points to fructose as a key driver of uncontrolled growth of the heart muscle, a condition that can lead to fatal heart failure. Their study was recently published in Nature.
When a person has high blood pressure, the heart has to grow as it is harder to pump the blood through the circulatory system. These growing heart muscle cells require a considerable amount of oxygen. However, since not enough oxygen is available to adequately supply the increased growth, the cells switch to an alternative energy supply. Instead of drawing energy from fatty acids, they rely more on an anaerobic process called glycolysis -- literally, the 'splitting of sugars'. If the heart muscle cells can access fructose in addition to glucose, this can set off a fatal chain reaction.
Flipping the switch for fructose metabolism
In the study, Krek's research group demonstrates that a lack of oxygen in the heart cells cues the appearance of the HIF molecule. This is a universal molecular switch that flips whenever a pathological growth process is under way, such as cardiac enlargement or cancer. HIF causes the heart muscle cells to produce ketohexokinase-C (KHK-C), the central enzyme in fructose metabolism. KHK-C has a high affinity for fructose and can therefore process it very efficiently. The production of KHK-C also has a reinforcing effect on glycolysis. Since fructose metabolism doesn't involve any negative feedback regulation, a vicious cycle starts that can lead to heart failure.
To investigate this mechanism, the researchers used not only mouse models but also biological samples from patients with pathological heart enlargement accompanied by a narrowing of the aortic valve. Samples of heart muscle cells taken by surgeons during heart operations provided the ETH researchers with the means for proving that such cells really do have more HIF and KHK-C molecules. In mice that were suffering from chronic high blood pressure, the researchers turned off the KHK enzyme, which indeed inhibited enlargement of the heart.
One gene, two enzymes
Another fact worthy of note is that the body also contains KHK-A, an enzyme very similar to KHK-C except that it has poor preference for fructose. Both these enzymes have the same genetic code; the difference between them comes from how a molecular cutting tool tailors their construction blueprint -- their messenger RNA, which is a transcript of the relevant gene. Depending on requirements, one of two blueprints can be generated from the same gene to produce either of two different enzymes. The expert term for this process is 'alternative splicing'. Krek explains, 'About 95 percent of all human genes are alternatively spliced. It's a major way to create the extraordinary variety of proteins, enzymes and regulators in the human body.'
Normally primarily liver cells produce the fructose-friendly KHK-C enzyme; other organs produce almost exclusively KHK-A. Now for the first time, the ETH researchers are showing that even an organ like the heart is capable of producing KHK-C, the more efficient of the two enzymes, if it is exposed to pathogenic stress factors. In the process, HIF activates the molecular cutting tool, or splicing factor, SF3B1. This molecule is often genetically altered in many types of cancer, which possibly indicates that even the growth of cancer can be affected by fructose.
Normal fruit consumption safe
Large volumes of fructose are added to many foods, but especially to sweet beverages and soft drinks. This practice drove up per capita consumption of high fructose corn syrup in the USA between 1970 and 1997, from 230 grams per year to over 28 kilograms.
But Mirtschink provides reassurance that eating a normal amount of fruit daily is safe and healthy. 'Besides fructose, fruit contains plenty of important trace elements, vitamins and fibre,' he says. People should, however, avoid overly sweet soft drinks and fruit juices -- these often have sugar added -- as well as ready-made meals and other foods to which large amounts of fructose are added as a flavour carrier. 'Just this surplus of fructose can help trigger the mechanism we have described if one of the stress factors is present, such as cardiac valve disease or high blood pressure,' Mirtschink emphasises.
In the last 40 years, fructose, a simple carbohydrate derived from fruit and vegetables, has been on the increase in American diets. Because of the addition of high-fructose corn syrup to many soft drinks and processed baked goods, fructose currently accounts for 10 percent of caloric intake for U.S. citizens. Male adolescents are the top fructose consumers, deriving between 15 to 23 percent of their calories from fructose--three to four times more than the maximum levels recommended by the American Heart Association.
A recent study at the Beckman Institute for Advanced Science and Technology at the University of Illinois found that, matched calorie for calorie with the simple sugar glucose, fructose causes significant weight gain, physical inactivity, and body fat deposition.
The paper, "Fructose decreases physical activity and increases body fat without affecting hippocampal neurogenesis and learning relative to an isocaloric glucose diet," was published in Scientific Reports.
"The link between increases in sugar intake, particularly fructose, and the rising obesity epidemic has been debated for many years with no clear conclusions," said Catarina Rendeiro, a postdoctoral research affiliate at the Beckman Institute for Advanced Science and Technology and lead author on the study. "The reality is that people are not only consuming more fructose through their diets, but also consuming more calories in general.
"One of the key questions is whether an increase in fructose intake contributes to obesity in the absence of excessive calorie intake."
The researchers, under the direction of Justin Rhodes of Beckman's NeuroTech Group and professor of psychology at Illinois, studied two groups of mice for two-and-a-half months: one group was fed a diet in which 18 percent of the calories came from fructose, mimicking the intake of adolescents in the United States, and the other was fed 18 percent from glucose.
"The important thing to note is that animals in both experimental groups had the usual intake of calories for a mouse," said Rendeiro. "They were not eating more than they should, and both groups had exactly the same amount of calories deriving from sugar, the only difference was the type of sugar, either fructose or glucose."
The results showed that the fructose-fed mice displayed significantly increased body weight, liver mass, and fat mass in comparison to the glucose-fed mice.
"In previous studies, the increases in fructose consumption were accompanied by increases in overall food intake, so it is difficult to know whether the animals put on weight due to the fructose itself or simply because they were eating more," Rhodes said.
Remarkably, the researchers also found that not only were the fructose-fed mice gaining weight, they were also less active.
"We don't know why animals move less when in the fructose diet," said Rhodes. "However, we estimated that the reduction in physical activity could account for most of the weight gain."
"Biochemical factors could also come into play in how the mice respond to the high fructose diet," explained Jonathan Mun, another author on the study. "We know that contrary to glucose, fructose bypasses certain metabolic steps that result in an increase in fat formation, especially in adipose tissue and liver."
The precise mechanisms are still being investigated, but one thing is certain: high intake of fructose by itself adds pounds.
"We designed this study based on the intake of fructose by adolescents in the United States," said Rhodes. "Our study suggests that such levels of fructose can indeed play a role in weight gain, favor fat deposition, and also contribute to physical inactivity. Given the dramatic increase in obesity among young people and the severe negative effects that this can have on health throughout one's life, it is important to consider what foods are providing our calories."
Not so bad
Fructose, the sugar often blamed for the obesity epidemic, does not itself have any impact on an emerging marker for the risk of cardiovascular disease known as postprandial triglycerides, new research has found.
However, overconsumption of calories from fructose can have substantial adverse effects on health, said Dr. John Sievenpiper, a researcher in the Clinical Nutrition and Risk Factor Modification Centre of St. Michael's Hospital.
"This is more evidence that fructose has adverse effects only insofar as it contributes to excess calories," said Dr. Sievenpiper.
Fructose, which is naturally found in fruit, vegetables and honey, is a simple sugar that together with glucose forms sucrose, the basis of table sugar. It is also found in high-fructose corn syrup, the most common sweetener in commercially prepared foods.
Dr. Sievenpiper conducted a meta-analysis of existing studies on fructose and its impact on the level of triglycerides, a fat found in blood, after eating. Testing for these triglycerides—in addition to the standard testing for blood glucose levels—is becoming more common for people trying to determine their risk for cardiovascular disease, although health care professionals remain divided on its usefulness.
Dr. Sievenpiper's results appear in the January 2014 issue of the journal Atheroclerosis.
"Fructose doesn't behave any differently than other refined carbohydrates," he said. "The increases you see are when fructose provides extra calories."
A new article published today in International Journal of Obesity found there is no evidence to suggest the current obesity epidemic in the United States can be specifically blamed on consumption of high fructose corn syrup (HFCS).
The commentary concludes that after an extensive review of all available HFCS research, there is overwhelming evidence showing HFCS is nutritionally equivalent to sugar. This opinion is in-line with the American Medical Association and the Academy of Nutrition and Dietetics, both of which concluded that HFCS is not a unique cause of obesity.
The authors state that while there has been a large amount of debate in the media about the impact of HFCS on obesity levels, the fact is "Sucrose (sugar) and HFCS are very similar in composition….and are absorbed identically in the human GI tract."
"The public discussion about HFCS will likely continue to rage on and more studies will be conducted," said James M. Rippe, M.D., Founder and Director of the Rippe Lifestyle Institute, and Professor of Biomedical Sciences at the University of Central Florida, one of the article's authors. "However, at this point there is simply no evidence to suggest that the use of HFCS alone is directly responsible for increased obesity rates or other health concerns."
The article goes on to discuss a number of research trials that have been conducted on the issue of HFCS and obesity, and concludes that at this time the evidence shows no short-term health differences between the use of HFCS or sugar could be detected in humans. Weight gain, glucose levels, insulin and appetite were not adversely affected by the use HFCS over sugar.
The commentary was co-authored with Dr. Rippe by David M. Klurfeld, Ph.D. of the USDA Agricultural Research Service, John Foreyt, Ph.D. of Baylor College of Medicine, and Theodore J. Angelopoulos, Ph.D., MPH Professor and Director, Laboratory of Applied Physiology Department of Health Professions at University of Central Florida.
HFCS was developed in the mid-1960's as a more flexible alternative to sugar and was widely embraced by the food industry. The use of HFCS grew rapidly from 1970-1999 where usage peaked. Since 1999, the use of HFCS has declined while obesity rates have continued to rise. Sucrose is still the dominant sweetener worldwide with over nine times the consumption of HFCS.
I eat a lot of fruit: raisins, grapes, blueberries, apples, strawberries, bananas, orange juice and tomatoes (yes, tomatoes are a fruit.) I always thought they were good for me (well orange juice in great moderation, only to enhance the benefits of green/white tea.)
Lots of research highlights the benefits:
Here are just a few examples:
1. Apples
2. Blueberries
Blueberries Help Build Strong Bones
Blueberries may inhibit development of fat cells
Blueberries: a Cup a Day May Keep Cancer Away
Blueberry’s positive effects on cholesterol
3. Strawberries
Strawberries Boost Red Blood Cells
Strawberries Fight Diabetes and Nervous System Diseases
Strawberries may slow precancerous growth
Strawberries Protect the Stomach from Alcohol
Even the government says fruits are good:
Almost Everyone Needs to Eat More Fruits and Vegetables
A growing body of research shows that fruits and vegetables are critical to promoting good health. To get the amount that's recommended, most people need to increase the amount of fruits and vegetables they currently eat every day. How Many Fruits and Vegetables Do You Need?
Fruits and Vegetables Can Protect Your Health
Fruits and vegetables contain essential vitamins, minerals, and fiber that may help protect you from chronic diseases. Compared with people who consume a diet with only small amounts of fruits and vegetables, those who eat more generous amounts as part of a healthful diet are likely to have reduced risk of chronic diseases, including stroke and perhaps other cardiovascular diseases, and certain cancers.
But a recent article sent to me by a reader/friend says quite the opposite:
A Word about Fructose (a Common Sugar in Soda, Fruit Juice and More) …
You will want to be very careful about the amount of fructose you consume as part of your carb intake, as it is by far the worst type of sugar there is in terms of both your health and your weight:
* After eating fructose, virtually all of the metabolic burden rests on your liver.
*Fructose is turned into free fatty acids (FFAs), VLDL (the damaging form of cholesterol), and triglycerides, which get stored as fat.
* The fatty acids created during fructose metabolism accumulate as fat droplets in your liver and skeletal muscle tissues, causing insulin resistance and non-alcoholic fatty liver disease (NAFLD). Insulin resistance progresses to metabolic syndrome and type 2 diabetes.
* Fructose is the most lipophilic carbohydrate. In other words, fructose converts to activated glycerol (g-3-p), which is directly used to turn FFAs into triglycerides. The more g-3-p you have, the more fat you store. Glucose simply does not do this.
* Consuming fructose is essentially consuming fat!
* The metabolism of fructose by your liver creates a long list of waste products and toxins, including a large amount of uric acid, which drives up blood pressure and can cause gout.
* Fructose has no effect on the hunger hormone ghrelin and by interfering with your brain's ability to use leptin, results in overeating.
If you want to shed excess pounds, maintain a healthy weight long-term, and RADICALLY reduce (and in many cases virtually eliminate) your risk of diabetes, heart disease and cancer, then get serious about restricting your consumption of fructose to no more than 25 grams per day, with a maximum of 15 grams a day from fresh fruit. If you're already overweight, or have any of these diseases or are at high risk of any of them, then you're probably better off cutting that down to 10-15 grams per day -- fruit included.
If you believe you are an exception to this rule then you can measure your uric acid level. If it is below 5 when you are eating loads of fruit then you are metabolically ok with it, as elevated uric acid levels are a strong indication of fructose toxicity.
So what should I do?
Well this article, Fructose: Sweet, But Dangerous, suggests that fruit isn't really so bad:
Fruits and vegetables have relatively small, "normal" amounts of fructose that most bodies can handle quite well... For example, a cup of chopped tomatoes has 2.5 grams of fructose, a can of regular (non-diet) soda supplies 23 grams, and a super-size soda has about 62 grams.
But this table tells me apples, grapes, and especially raisins, are particularly bad.
My conclusion - I'm going to go right on eating most of my fruits but will cut down on raisins, which I use to sweeten my daily oat meal ( the subject of my next, similar, post).
More on Fructose (Some of it quite contradictory):
Bad
Fructose produces less rewarding sensations in the brain
Fructose not only results in a lower level of satiety, it also stimulates the reward system in the brain to a lesser degree than glucose. This may cause excessive consumption accompanied by effects that are a risk to health, report researchers from the University of Basel in a study published in the scientific journal PLOS ONE. Various diseases have been attributed to industrial fructose in sugary drinks and ready meals.
Fruit sugar, or fructose, is a carbohydrate that occurs naturally in fruits and vegetables and is generally harmless in this form. Despite their similar structures, fructose and glucose - that is, pure grape sugar - affect the body very differently: an intake of glucose causes a sharp increase in blood insulin within minutes, whereas fructose stimulates insulin secretion to a limited degree only.
Teams of researchers led by Professor Christoph Beglinger from the University Hospital and Professor Stefan Borgwardt from the Psychiatric University Clinics (UPK Basel) have now taken a more in-depth look at how these two types of sugar affect interactions between the gastrointestinal tract and the brain. Their work was funded by the Swiss National Science Foundation. In their study, the researchers used combined pharmacological and imaging methods such as functional magnetic resonance imaging (MRI).
Brain activity examined
In the placebo-controlled, double-blind study, twelve healthy young men were given either fructose, glucose or a placebo by way of a feeding tube. Blood samples were then taken from the subjects to measure satiety hormones. The subjects were also asked about how satiated they felt, and their brain activity was monitored by MRI while at rest.
The findings of the pilot study were as follows. Unlike glucose, fructose is less effective at creating feelings of satiety and stimulating the reward system in the brain. An analysis of the MRIs in fact showed that the two types of sugar differed greatly in terms of network activation within the hippocampus and amygdala areas of the limbic system, i.e. the regions of the brain that regulate emotions and impulses. Furthermore, in contrast to glucose (which stimulated a strong signal) the levels of satiety hormones in the blood barely or only minimally increased following fructose consumption. The subjective feeling of satiety also tended to be less affected by the consumption of fructose.
The problem of fructose
"The study may provide the first key findings about the lack of satiety and rewarding effects triggered by fructose," state lead authors Dr Bettina Wölnerhanssen and Dr Anne Christin Meyer-Gerspach. The role of the differing insulin levels and other effects will have to be demonstrated in further studies with more test subjects. Research is increasingly finding indications that isolated, industrially manufactured fructose - which is increasingly used in sugary drinks, sweets and ready meals - is problematic for the human body. It is suspected that fructose promotes the development of various disorders such as obesity, diabetes, fatty liver disease and gout.
Fructose powers a vicious circle
'Walk through any supermarket and take a look at the labels on food products, and you'll see that many of them contain fructose, often in the form of sucrose (table sugar)' -- that's how Wilhelm Krek, professor for cell biology at ETH Zurich's Institute for Molecular Health Sciences, summarises the problem with today's nutrition. Prepared foods and soft drinks in particular, but even purportedly healthy fruit juices contain fructose as an artificial additive -- often in high quantities. In recent decades fructose spread throughout the food market, due to a reputation as being less harmful than glucose. In contrast to glucose, fructose barely increases blood glucose levels and insulin secretion. This avoids frequently recurring insulin spikes after any glucose consumption, which are judged harmful. In addition, fructose is sweeter to the taste.
But there's a downside: the liver converts fructose very efficiently into fat. People who consume too much high-fructose food can in time become overweight and develop high blood pressure, dyslipidaemia with fatty liver and insulin resistance -- symptoms that doctors group together under the name metabolic syndrome.
Unchecked growth of the heart muscle
A new paper by Krek and his team member Peter Mirtschink describes a further, more troubling side effect of fructose. The researchers have discovered a previously unknown molecular mechanism that points to fructose as a key driver of uncontrolled growth of the heart muscle, a condition that can lead to fatal heart failure. Their study was recently published in Nature.
When a person has high blood pressure, the heart has to grow as it is harder to pump the blood through the circulatory system. These growing heart muscle cells require a considerable amount of oxygen. However, since not enough oxygen is available to adequately supply the increased growth, the cells switch to an alternative energy supply. Instead of drawing energy from fatty acids, they rely more on an anaerobic process called glycolysis -- literally, the 'splitting of sugars'. If the heart muscle cells can access fructose in addition to glucose, this can set off a fatal chain reaction.
Flipping the switch for fructose metabolism
In the study, Krek's research group demonstrates that a lack of oxygen in the heart cells cues the appearance of the HIF molecule. This is a universal molecular switch that flips whenever a pathological growth process is under way, such as cardiac enlargement or cancer. HIF causes the heart muscle cells to produce ketohexokinase-C (KHK-C), the central enzyme in fructose metabolism. KHK-C has a high affinity for fructose and can therefore process it very efficiently. The production of KHK-C also has a reinforcing effect on glycolysis. Since fructose metabolism doesn't involve any negative feedback regulation, a vicious cycle starts that can lead to heart failure.
To investigate this mechanism, the researchers used not only mouse models but also biological samples from patients with pathological heart enlargement accompanied by a narrowing of the aortic valve. Samples of heart muscle cells taken by surgeons during heart operations provided the ETH researchers with the means for proving that such cells really do have more HIF and KHK-C molecules. In mice that were suffering from chronic high blood pressure, the researchers turned off the KHK enzyme, which indeed inhibited enlargement of the heart.
One gene, two enzymes
Another fact worthy of note is that the body also contains KHK-A, an enzyme very similar to KHK-C except that it has poor preference for fructose. Both these enzymes have the same genetic code; the difference between them comes from how a molecular cutting tool tailors their construction blueprint -- their messenger RNA, which is a transcript of the relevant gene. Depending on requirements, one of two blueprints can be generated from the same gene to produce either of two different enzymes. The expert term for this process is 'alternative splicing'. Krek explains, 'About 95 percent of all human genes are alternatively spliced. It's a major way to create the extraordinary variety of proteins, enzymes and regulators in the human body.'
Normally primarily liver cells produce the fructose-friendly KHK-C enzyme; other organs produce almost exclusively KHK-A. Now for the first time, the ETH researchers are showing that even an organ like the heart is capable of producing KHK-C, the more efficient of the two enzymes, if it is exposed to pathogenic stress factors. In the process, HIF activates the molecular cutting tool, or splicing factor, SF3B1. This molecule is often genetically altered in many types of cancer, which possibly indicates that even the growth of cancer can be affected by fructose.
Normal fruit consumption safe
Large volumes of fructose are added to many foods, but especially to sweet beverages and soft drinks. This practice drove up per capita consumption of high fructose corn syrup in the USA between 1970 and 1997, from 230 grams per year to over 28 kilograms.
But Mirtschink provides reassurance that eating a normal amount of fruit daily is safe and healthy. 'Besides fructose, fruit contains plenty of important trace elements, vitamins and fibre,' he says. People should, however, avoid overly sweet soft drinks and fruit juices -- these often have sugar added -- as well as ready-made meals and other foods to which large amounts of fructose are added as a flavour carrier. 'Just this surplus of fructose can help trigger the mechanism we have described if one of the stress factors is present, such as cardiac valve disease or high blood pressure,' Mirtschink emphasises.
Fructose contributes to weight gain, physical inactivity, and body fat
In the last 40 years, fructose, a simple carbohydrate derived from fruit and vegetables, has been on the increase in American diets. Because of the addition of high-fructose corn syrup to many soft drinks and processed baked goods, fructose currently accounts for 10 percent of caloric intake for U.S. citizens. Male adolescents are the top fructose consumers, deriving between 15 to 23 percent of their calories from fructose--three to four times more than the maximum levels recommended by the American Heart Association.
A recent study at the Beckman Institute for Advanced Science and Technology at the University of Illinois found that, matched calorie for calorie with the simple sugar glucose, fructose causes significant weight gain, physical inactivity, and body fat deposition.
The paper, "Fructose decreases physical activity and increases body fat without affecting hippocampal neurogenesis and learning relative to an isocaloric glucose diet," was published in Scientific Reports.
"The link between increases in sugar intake, particularly fructose, and the rising obesity epidemic has been debated for many years with no clear conclusions," said Catarina Rendeiro, a postdoctoral research affiliate at the Beckman Institute for Advanced Science and Technology and lead author on the study. "The reality is that people are not only consuming more fructose through their diets, but also consuming more calories in general.
"One of the key questions is whether an increase in fructose intake contributes to obesity in the absence of excessive calorie intake."
The researchers, under the direction of Justin Rhodes of Beckman's NeuroTech Group and professor of psychology at Illinois, studied two groups of mice for two-and-a-half months: one group was fed a diet in which 18 percent of the calories came from fructose, mimicking the intake of adolescents in the United States, and the other was fed 18 percent from glucose.
"The important thing to note is that animals in both experimental groups had the usual intake of calories for a mouse," said Rendeiro. "They were not eating more than they should, and both groups had exactly the same amount of calories deriving from sugar, the only difference was the type of sugar, either fructose or glucose."
The results showed that the fructose-fed mice displayed significantly increased body weight, liver mass, and fat mass in comparison to the glucose-fed mice.
"In previous studies, the increases in fructose consumption were accompanied by increases in overall food intake, so it is difficult to know whether the animals put on weight due to the fructose itself or simply because they were eating more," Rhodes said.
Remarkably, the researchers also found that not only were the fructose-fed mice gaining weight, they were also less active.
"We don't know why animals move less when in the fructose diet," said Rhodes. "However, we estimated that the reduction in physical activity could account for most of the weight gain."
"Biochemical factors could also come into play in how the mice respond to the high fructose diet," explained Jonathan Mun, another author on the study. "We know that contrary to glucose, fructose bypasses certain metabolic steps that result in an increase in fat formation, especially in adipose tissue and liver."
The precise mechanisms are still being investigated, but one thing is certain: high intake of fructose by itself adds pounds.
"We designed this study based on the intake of fructose by adolescents in the United States," said Rhodes. "Our study suggests that such levels of fructose can indeed play a role in weight gain, favor fat deposition, and also contribute to physical inactivity. Given the dramatic increase in obesity among young people and the severe negative effects that this can have on health throughout one's life, it is important to consider what foods are providing our calories."
Not so bad
Fructose does not impact emerging indicator for cardiovascular disease
Fructose, the sugar often blamed for the obesity epidemic, does not itself have any impact on an emerging marker for the risk of cardiovascular disease known as postprandial triglycerides, new research has found.
However, overconsumption of calories from fructose can have substantial adverse effects on health, said Dr. John Sievenpiper, a researcher in the Clinical Nutrition and Risk Factor Modification Centre of St. Michael's Hospital.
"This is more evidence that fructose has adverse effects only insofar as it contributes to excess calories," said Dr. Sievenpiper.
Fructose, which is naturally found in fruit, vegetables and honey, is a simple sugar that together with glucose forms sucrose, the basis of table sugar. It is also found in high-fructose corn syrup, the most common sweetener in commercially prepared foods.
Dr. Sievenpiper conducted a meta-analysis of existing studies on fructose and its impact on the level of triglycerides, a fat found in blood, after eating. Testing for these triglycerides—in addition to the standard testing for blood glucose levels—is becoming more common for people trying to determine their risk for cardiovascular disease, although health care professionals remain divided on its usefulness.
Dr. Sievenpiper's results appear in the January 2014 issue of the journal Atheroclerosis.
"Fructose doesn't behave any differently than other refined carbohydrates," he said. "The increases you see are when fructose provides extra calories."
Scientists conclude high fructose corn syrup should not be blamed for obesity
A new article published today in International Journal of Obesity found there is no evidence to suggest the current obesity epidemic in the United States can be specifically blamed on consumption of high fructose corn syrup (HFCS).
The commentary concludes that after an extensive review of all available HFCS research, there is overwhelming evidence showing HFCS is nutritionally equivalent to sugar. This opinion is in-line with the American Medical Association and the Academy of Nutrition and Dietetics, both of which concluded that HFCS is not a unique cause of obesity.
The authors state that while there has been a large amount of debate in the media about the impact of HFCS on obesity levels, the fact is "Sucrose (sugar) and HFCS are very similar in composition….and are absorbed identically in the human GI tract."
"The public discussion about HFCS will likely continue to rage on and more studies will be conducted," said James M. Rippe, M.D., Founder and Director of the Rippe Lifestyle Institute, and Professor of Biomedical Sciences at the University of Central Florida, one of the article's authors. "However, at this point there is simply no evidence to suggest that the use of HFCS alone is directly responsible for increased obesity rates or other health concerns."
The article goes on to discuss a number of research trials that have been conducted on the issue of HFCS and obesity, and concludes that at this time the evidence shows no short-term health differences between the use of HFCS or sugar could be detected in humans. Weight gain, glucose levels, insulin and appetite were not adversely affected by the use HFCS over sugar.
The commentary was co-authored with Dr. Rippe by David M. Klurfeld, Ph.D. of the USDA Agricultural Research Service, John Foreyt, Ph.D. of Baylor College of Medicine, and Theodore J. Angelopoulos, Ph.D., MPH Professor and Director, Laboratory of Applied Physiology Department of Health Professions at University of Central Florida.
HFCS was developed in the mid-1960's as a more flexible alternative to sugar and was widely embraced by the food industry. The use of HFCS grew rapidly from 1970-1999 where usage peaked. Since 1999, the use of HFCS has declined while obesity rates have continued to rise. Sucrose is still the dominant sweetener worldwide with over nine times the consumption of HFCS.
Blueberries and Strawberries
Blueberries Help Build Strong Bones
Blueberries may inhibit development of fat cells
Blueberries: a Cup a Day May Keep Cancer Away
Blueberry’s positive effects on cholesterol
Strawberries Boost Red Blood Cells
Strawberries Fight Diabetes and Nervous System Diseases
Strawberries may slow precancerous growth
Strawberries Protect the Stomach from Alcohol
Blueberries may inhibit development of fat cells
Blueberries: a Cup a Day May Keep Cancer Away
Blueberry’s positive effects on cholesterol
Strawberries Boost Red Blood Cells
Strawberries Fight Diabetes and Nervous System Diseases
Strawberries may slow precancerous growth
Strawberries Protect the Stomach from Alcohol
Apples
'Apple a day' advice rooted in science
Everyone has heard the old adage, "an apple a day keeps the doctor away." We all know we should eat more fruit. But why apples? Do they contain specific benefits?
According to Dr. Bahram H. Arjmandi, PhD, RD, Margaret A. Sitton Professor and Chair, Department of Nutrition, Food and Exercise Sciences at The Florida State University, apples are truly a "miracle fruit" that convey benefits beyond fiber content. Animal studies have shown that apple pectin and polyphenols in apple improve lipid metabolism and lower the production of pro-inflammatory molecules. Arjmandi's most recent research is the first to evaluate the long-term cardioprotective effects of daily consumption of apple in postmenopausal women. The results of this USDA-funded study will be presented at Experimental Biology 2011 on Tuesday, April 12, at 12:45 pm in Washington, DC.
This study randomly assigned 160 women ages 45-65 to one of two dietary intervention groups: one received dried apples daily (75g/day for 1 year) and the other group ate dried prunes every day for a year. Blood samples were taken at 3, 6 and 12-months. The results surprised Dr. Arjmandi, who stated that "incredible changes in the apple-eating women happened by 6 months- they experienced a 23% decrease in LDL cholesterol," which is known as the "bad cholesterol." The daily apple consumption also led to a lowering of lipid hydroperoxide levels and C-reactive protein in those women.
"I never expected apple consumption to reduce bad cholesterol to this extent while increasing HDL cholesterol or good cholesterol by about 4%," Arjmandi said. Yet another advantage is that the extra 240 calories per day consumed from the dried apple did not lead to weight gain in the women; in fact, they lost on average 3.3 lbs. "Reducing body weight is an added benefit to daily apple intake" he said. Part of the reason for the weight loss could be the fruit's pectin, which is known to have a satiety effect. The next step in confirming the results of this study is a multi-investigator nationwide study.
There is frequently some truth behind our common expressions, and in the case of 'an apple a day,' Dr. Arjmandi has shown that nutrition science backs up the expression. "Everyone can benefit from consuming apples," he said.
An Apple Peel a Day Could Keep Cancer at Bay
An apple peel a day might help keep cancer at bay, according to Rui Hai Liu, Cornell associate professor of food science, who has identified a dozen compounds -- triterpenoids -- in apple peel that either inhibit or kill cancer cells in laboratory cultures. Three of the compounds have not previously been described in the literature.
"We found that several compounds have potent anti-proliferative activities against human liver, colon and breast cancer cells and may be partially responsible for the anti-cancer activities of whole apples," says Liu, who is affiliated with Cornell's Institute of Comparative and Environmental Toxicology and is senior author of the study, which is online and published in the Journal of Agricultural and Food Chemistry.
In previous Cornell studies, apples had been found not only to fight cancer cells in the laboratory but also to reduce the number and size of mammary tumors in rats. The Cornell researchers now think that the triterpenoids may be doing much of the anti-cancer work.
"Some compounds were more potent and acted differently against the various cancer cell lines, but they all show very potent anti-cancer activities and should be studied further," says Liu.
With co-author Xiangjiu He, a Cornell postdoctoral researcher, Liu analyzed the peel from 230 pounds of red delicious apples from the Cornell Orchard and isolated their individual compounds. After identifying the structures of the promising compounds in the peel, the researchers tested the pure compounds against cancer cell growth in the laboratory. In the past, Liu has also identified compounds called phytochemicals -- mainly flavonoids and phenolic acids -- in apples and other foods that appear to be have anti-cancer properties as well, including inhibiting tumor growth in human breast cancer cells.
"We believe that a recommendation that consumers to eat five to 12 servings of a wide variety of fruits and vegetables daily is appropriate to reduce the risks of chronic diseases, including cancer, and to meet nutrient requirements for optimum health," said Liu.
The study online: http://pubs.acs.org/cgi-bin/abstract.cgi/jafcau/2007/55/i11/abs/jf063563o.html
Adults who eat apples, drink apple juice have lower risk for metabolic syndrome
Apple product consumers likely to have lower blood pressure, trimmer waistlines, and more nutrient dense diets
Not eating your apple a day" Perhaps you should be. Adults who eat apples, apple juice and applesauce have a significantly reduced risk of metabolic syndrome, a cluster of health problems that are linked to numerous chronic diseases such as diabetes and cardiovascular disease.
The study results, presented at the Experimental Biology 2008 meeting this week, were derived from an analysis of adult food consumption data collected in the 1999-2004 National Health and Nutrition Examination Survey (NHANES), the government’s largest food consumption and health database.
Dr. Victor Fulgoni analyzed the data, specifically looking at the association between consumption of apples and apple products, nutrient intake and various physiological parameters related to metabolic syndrome. When compared to non-consumers, adult apple product consumers had a 27% decreased likelihood of being diagnosed with metabolic syndrome.
Fulgoni notes, “We found that adults who eat apples and apple products have smaller waistlines that indicate less abdominal fat, lower blood pressure and a reduced risk for developing what is known as the metabolic syndrome.”
In addition to having a 30% decreased likelihood for elevated diastolic blood pressure and a 36% decreased likelihood for elevated systolic blood pressure, apple product consumers also had a 21% reduced risk of increased waist circumference – all predictors of cardiovascular disease and an increased likelihood of metabolic syndrome. Additionally, adult apple product consumers had significantly reduced C-reactive protein levels, another measurable marker related to cardiovascular risk.
Furthermore, apple product consumers’ diets were healthier than non-consumers – they had an overall greater intake of fruit and key nutrients, including dietary fiber, vitamins A and C, calcium and potassium. These consumers also ate less total fat, saturated fat, discretionary fat and added sugars.
Apple pectin, apple juice extracts shown to have anticarcinogenic effects on colon
The apples and apple juice you consume may have positive effects in one of the most unlikely places in the body – in the colon. New research has demonstrated that both apple pectin and polyphenol-rich apple juice components actually enhance biological mechanisms that produce anticarcinogenic compounds during the fermentation process.
Using human fecal matter as the test substance, German researchers Dr. Dieter Schrenk, M.D. and his colleagues hypothesized that the compound butyrate could be increased in the presence of apple pectin and apple juice extracts.
Butyrate has been suggested to be a chemopreventative metabolite that might prevent the occurrence of colorectal cancer, which is very common in Western industrialized countries. It is a short chain fatty acid which is seen as a major factor contributing to healthy colon mucosa. The research notes, “Butyrate not only serves as a major nutrient for the colon epithelia but is also thought to play an important role in the protective effect of natural fiber against colorectal cancer.”
So how do apple pectin and apple juice extracts play a role in increasing amounts of butyrate? The laboratory tests performed by Schrenk found that by the increased production of butyrate via the addition of apple components, histone deacetlyases (HDAC) were inhibited. With slowed production of HDAC, there would be significantly less growth of precancerous and tumor cells.
The research, published in the April 2008 issue of Nutrition, notes, “apples are a major source of natural fiber and of low molecular weight plan polyphenols in the Western diet.” The researchers conclude, “Pectin-rich apple products can thus be expected to exert anticarginogenic effects in the colon.”
Apple consumers reap heart-health benefits
Apple consumers reap heart-health benefits thanks to flavonoid content, says new research
American Heart Association new recommendations support increased fruit, vegetable consumption
Apples may prove to be a winner when it comes to reducing the risk of heart disease, says a new study of more than 34,000 women. In this study, flavonoid-rich apples were found to be one of three foods (along with red wine and pears) that decrease the risk of mortality for both coronary heart disease (CHD) and cardiovascular disease (CVD) among post-menopausal women, The findings were published in the March 2007 American Journal of Clinical Nutrition.
Women of all ages are encouraged to consume more fruit and vegetables, including apples and apple products, for heart health. However, this study focused on postmenopausal woman, a group becoming more aware of the risk for heart disease. Using a government database that assesses the flavonoid-compound content of foods, the researchers hypothesized that flavonoid intake (in general and from specific foods), might be inversely associated with mortality from CVD and CHD among the women in the study groupSubjects selected for this research analysis were postmenopausal and part of the ongoing Iowa Women's Health Study, each of which has been monitored for dietary intake and various health outcomes for nearly 20 years.
As a result of the extensive analysis that considered what the women ate, the types of cardiovascular-related diseases they experienced, and the overall flavonoid content of an extensive list of foods, the researchers concluded that consumption of apples, pears and red wine were linked with the lowest risk for mortality related to both CHD and CVD (not just one or the other).
"Flavonoids are compounds found in small quantities in numerous plant foods, including fruits and vegetables, tea, wine, nuts and seeds, and herbs and spices," say the university researchers from the University of Minnesota and the University of Oslo (Norway) Earlier research has indicated that flavonoids also have antioxidant properties that are linked to the reduction of oxidation of the bad (LDL - low density lipoprotein) cholesterol which have been linked in various ways with the development of CVD. According to the government database cited in this paper, apples contain a wide variety of flavonoid compounds.
The researchers also believe this is the first prospective study of postmenopausal women to report on the intake and impact of total and specific flavonoid subclasses. They conclude, "Dietary intakes of flavanones, anthocyanins, and certain foods rich in flavonoids were associated with reduced risk of death due to CHD, CVD and all causes."_
The publication of this positive study for apples comes on the heels of updated heart disease prevention guidelines for women just released by the American Heart Association in the February 20 issue of Circulation. As part of their guidelines, AHA emphasizes that women increase their intake of fruits and vegetables to help prevent heart disease over their lifetime, not just to reduce short-term risk. Worldwide, cardiovascular disease is the largest single cause of mortality among women, accounting for one third of all deaths.
Can an apple a day keep asthma away?
Poor diets show increased respiratory symptoms in teens
Teenagers who forego a healthy and balanced diet may have a harder time catching their breath. A new study, published in the July issue of CHEST, the peer-reviewed journal of the American College of Chest Physicians (ACCP), shows that a low dietary intake of certain nutrients increases the likelihood of respiratory symptoms such as asthma, especially in teens who smoke. Furthermore, a lack of these nutrients may also lead to lower lung function.
“Our study, as well as other research, suggests that higher intakes of antioxidant and anti-inflammatory micronutrients are associated with lower reports of cough, respiratory infections, and less severe asthma-related symptoms,” said lead study author Jane Burns, ScD, Harvard School of Public Health. “Teenagers who have low dietary intakes of fruit, vitamin E, and omega-3 fatty acids are at greater risk of having asthma, emphasizing the importance of a balanced diet, composed of whole foods.”
While observing 12th-grade students from 12 communities around the US and Canada, Dr. Burns and her colleagues from the Harvard School of Public Health, Health Canada, Brigham and Women’s Hospital, and the Environmental Protection Agency (EPA), examined the associations of low dietary nutrient intake with low pulmonary function and respiratory symptoms. Over the period of one school year, 2,112 students completed a standardized respiratory questionnaire and a dietary questionnaire. They also answered questions about medication use, smoking habits, and recent exercise, before participating in lung function testing. Dr. Burns explained that the researchers focused on teens because it is the ideal age at which to test lung capacity and eating habits.
“During late adolescence, physical stature has, on average, been attained and lung growth closely parallels this growth. Therefore we were observing a time when lung function was close to its optimal capacity,” she said. “Also, although our diet survey targeted eating habits only during the past year, it did give us some idea of the teens’ general past diet. However, their current respiratory health may be a reflection of diet during childhood, as well as during the past year.”
The majority of adolescents in the study were white, one third was overweight, and 72% did not consume multivitamins. Also, nearly 25% reported smoking on a daily basis. Researchers also found that at least one third of the students’ diets were below the recommended levels of fruit, vegetable, vitamins A and E, beta-carotene, and omega-3 fatty acid intake.
“Vitamin supplements can help teens meet their daily recommended levels,” said Dr. Burns, “and surprisingly, even relatively low levels of omega-3 fatty acids appeared to protect teens from higher reported respiratory symptoms.”
Results showed that low dietary intakes of fruit, vitamins C and E, and omega-3 fatty acids were associated with decreased lung function and a greater risk of chronic bronchitic symptoms, wheeze, and asthma. These risks were further increased among students with the lowest intakes and who also smoked.
“I wish we could say that an apple a day can keep asthma away, but it’s a complex disease with a genetic component. However, it may be that certain foods can lessen or prevent asthma symptoms,” said Dr. Burns. “The most important thing to remember is that diet can have a significant impact on teens’ respiratory health. I would encourage them to make healthy eating a part of their daily routine, and stress to them that smoking is bad.” Researchers emphasized that fresh fruits make for convenient snacks. They also suggest preparing a simple, daily family meal, as a method to promote both communication and good nutrition.
“A balanced diet is not only good for lung health, but for general health,” said Mark J. Rosen, MD, FCCP, President of the American College of Chest Physicians. “Parents and physicians should work together to monitor and maintain healthy diets and lifestyles for children of all ages.”
Apples, apple juice shown to prevent early atherosclerosis
A new study shows that apples and apple juice are playing the same health league as the often-touted purple grapes and grape juice. The study was published in the April 2008 issue of Molecular Nutrition and Food Research.
Researcher Kelly Decorde from the Universite Montpelier in France was part of the European research team that found apples have similar cardiovascular protective properties to grapes. The researchers also observed that processing the fruit into juice has the potential to increase the bioavailability of the naturally-occurring compounds and antioxidants found in the whole fruit.
Using a variety of established analytical techniques, aortic plaque was evaluated to determine the effectiveness in decreasing plaque that is associated with atherosclerosis.
According to the research, “This study demonstrates that processing apples and purple grapes into juice modifies the protective effect of their phenolics against diet induced oxidative stress and early atherosclerosis in hypercholesterolemic hamsters.”
Researchers also noted, “These results show for the first time that long-term consumption of antioxidants supplied by apples and purple grapes, especially phenolic compounds, prevents the development of atherosclerosis in hamsters, and that the processing can have a major impact on the potential health effects of a product.”
In summary, the researchers stated that their work would help provide encouragement that fruit and fruit juices may have significant clinical and public health relevance.
Apples, Apple Juice Lower Wheezing and Asthma Risk in Children
Published in the September 2007 issue of Thorax, the latest study finds that when women ate apples during pregnancy, researchers found a significant decrease in asthma and wheezing among their children when the children were followed over five years and reached five years of age.
This unique longitudinal study tracked dietary intake by 1253 mother-child pairs. According to the researchers that conducted medical evaluations for asthma and related symptoms (i.e., wheezing) in the children, they found no other association with decreased risk other than for apple consumption. The only other positive association found between prenatal food intake and risk reduction in the children was with fish intake by the mothers, for which the researchers found that children of mothers who ate fish had a lowered incidence of doctor-confirmed eczema.
A similar but different study published June 2007 also showed a link between apple juice consumption and a reduction in wheezing among children. That study was published in June’s European Respiratory Journal.
Among children who experienced what was characterized as “current wheeze” (where the child had wheezing or whistling in the chest in the last 12 months), there was a significant, dose response association between consumption of apple juice and a reduced incidence of the wheezing. The researchers found that drinking apple juice made from concentrate and consumption of bananas one or more times a day (compared to drinking apple juice or eating bananas less than once a month) was directly associated with improvement of wheezing occurences.
According to the authors of the Thorax paper, the protective effect from apples is attributable to their powerful phytochemical content, which includes flavonoids, isoflavonoids, and phenolic acids. Apples and apple products combined are the largest source of free phenolics in people’s diet in the US and in Europe.
The American Lung Association states that asthma remains a major public health concern. In 2003, approximately 20 million Americans had asthma and the condition accounted for an estimated 12.8 million lost school days in children. Asthma ranks within the top ten prevalent conditions causing limitation of activity and costs our nation $16.1 billion in health care costs annually.
Apple's benefits reach into the womb to fight asthma
Eating apples while pregnant may give new meaning to an apple a day keeping the doctor away. Compelling new research has concluded that mothers who eat apples during pregnancy may protect their children from developing asthma later in life. The study was published in Thorax online.
This unique longitudinal study tracked dietary intake by nearly 2000 pregnant women, then examined the effects of the maternal diet on airway development in more than 1200 of their children five years later. Among a wide variety of foods consumed and recorded by the pregnant women, the researchers concluded that the children of mothers who ate apples had a significantly reduced risk for the development of asthma and childhood wheezing.
This study focuses on medical evaluations for asthma and related symptoms (i.e., wheezing) when the children were five years old. As a result of the evaluations cited in this research, other than apples, there were no consistent associations found between prenatal consumption of a range of healthful foods and asthma in the 1253 children who were evaluated.
Children of mothers who ate apples during pregnancy were much less likely to exhibit symptoms of asthma (including wheezing), say the researchers who hail from institutions in The Netherlands and Scotland. These same researchers previously reported positive associations between maternal consumption of vitamins A, E, D and zinc with reduced risk of asthma, wheeze and eczema in children.
The only other positive association found between prenatal food intake and risk reduction in the children was with fish, for which the researchers found that children of mothers who ate fish had a lowered incidence of doctor-confirmed eczema.
According to the research, "The present study suggests beneficial associations between maternal apple intake during pregnancy and wheeze and asthma at age five years." They add that their findings "suggest an apple specific effect, possibly because of its phytochemical content, such as flavonoids." The research paper cites other related studies on apples, including those which found that "intake of apples as a significant source of flavonoids and other polyphenols has been beneficially associated with asthma, bronchial hypersensitivity, and lung function in adults."
In 2004, the National Center for Health Statistics reported that nine million U.S. children have been diagnosed with asthma at one point in their lives and four million children suffered from asthma attacks that year. Others suffer from "hidden asthma" – undetected or undiagnosed asthma, according the American Lung Association. The cost of this disease is great – statistics show asthma to be the third-ranking cause of hospitalization among children under 15 and is among the leading causes of school absenteeism.
Eating apples/fish helps vs asthma/allergies
Women who eat apples and fish during pregnancy may reduce the risk of their children developing asthma or allergic disease, suggests a new study presented at the American Thoracic Society 2007 International Conference, on Sunday, May 20.
The SEATON study, conducted at the University of Aberdeen, UK, found that the children of mothers who ate the most apples were less likely to ever have wheezed or have doctor-confirmed asthma at the age of 5 years, compared to children of mothers who had the lowest apple consumption. Children of mothers who ate fish once or more a week were less likely to have had eczema than children of mothers who never ate fish.
The study did not find any protective effect against asthma or allergic diseases from many other foods, including vegetables, fruit juice, citrus or kiwi fruit, whole grain products, fat from dairy products or margarine or other low-fat spreads.
The researchers studied 1212 children born to women who had filled out food questionnaires during their pregnancy. When the children were 5 years old, the mothers filled out a questionnaire about the children’s respiratory symptoms and allergies, as well as a questionnaire about their child’s food consumption.
The children were also given lung function and allergy tests. Previous studies in the same children have found evidence for protective effects of vitamin E and D and zinc during pregnancy in reducing the risk of children’s wheeze and asthma, notes researcher Saskia Willers, M.Sc. of Utrecht University in the Netherlands. If the new results are confirmed, she says, "recommendations on dietary modification during pregnancy may help to prevent childhood asthma and allergy."
Willers concludes that at least until age 5, a mother’s diet during pregnancy might be more influential on a child’s respiratory health than the child’s own diet. She notes that further study of this group of children will be needed to see whether the association with the mothers’ diet declines in older children, and if mothers’ and their childrens’ diets interact in older children.
Willers suggests that the beneficial effect of apples may come from powerful antioxidants called flavonoids, while fish’s protective effect may come from omega-3 fatty acids, which other studies have suggested have a protective effect on the heart and may have a protective effect in asthma. "Other studies have looked at individual nutrients’ effect on asthma in pregnancy, but our study looked at specific foods during pregnancy and the subsequent development of childhood asthma and allergies, which is quite new," Willers says. "Foods contain mixtures of nutrients that may contribute more than the sum of their parts."
Naturally-occurring apple compounds reduce risk of pancreatic cancer
Smokers benefit most from intake of 'hidden' plant nutrients
Eating flavonol-rich foods like apples may help reduce the risk of pancreatic cancer, says a team of international researchers. Quercetin, which is found naturally in apples and onions, has been identified as one of the most beneficial flavonols in preventing and reducing the risk of pancreatic cancer. Although the overall risk was reduced among the study participants, smokers who consumed foods rich in flavonols had a significantly greater risk reduction.
This study, published in the October 15 issue of the American Journal of Epidemiology, is the first of its kind to evaluate the effect of flavonols – compounds found specifically in plants – on developing pancreatic cancer. According to the research paper, “only a few prospective studies have investigated flavonols as risk factors for cancer, none of which has included pancreatic cancer. “
Researchers from Germany, the Univ. of Hawaii and Univ. of Southern California tracked food intake and health outcomes of 183,518 participants in the Multiethnic Cohort Study for eight years. The study evaluated the participants’ food consumption and calculated the intake of the three flavonols quercetin, kaempferol, and myricetin. The analyses determined that flavonol intake does have an impact on the risk for developing pancreatic cancer.
The most significant finding was among smokers. Smokers with the lowest intake of flavonols presented with the most pancreatic cancer. Smoking is an established risk factor for the often fatal pancreatic cancer, notes the research.
Among the other findings were that women had the highest intake of total flavonols and seventy percent of the flavonol intake came from quercetin, linked to apple and onion consumption.
It is believed that these compounds may have anticancer effects due to their ability to reduce oxidative stress and alter other cellular functions related to cancer development.
“Unlike many of the dietary components, flavonols are concentrated in specific foods rather than in broader food groups, for example, in apples rather than in all fruit,” notes the research study. Previously, the most consistent inverse association was found between flavonols, especially quercetin in apples and lung cancer, as pointed out in this study. No other epidemiological flavonol studies have included evaluation of pancreatic cancer.
While found in many plants, flavonols are found in high concentrations in apples, onions, tea, berries, kale, and broccoli. Quercetin is most plentiful in apples and onions.
Compound in Apples Inhibits E. coli
A compound that is abundant in apples and strawberries inhibits the highly pathogenic E. coli O157:H7 biofilms while sparing a beneficial strain of E. coli that also forms biofilms in the human gut, according to a paper in the December 2011 issue of the journal Infection and Immunology.
Transcriptome analysis revealed that the compound, called phloretin, suppresses toxin and other genes involved in O157:H7 pathology and biofilm formation. And in a rat model of colitis, phloretin, reduced colon inflammation and body weight loss. "Phloretin has a triple biological activity as an antioxidant compound, a biofilm inhibitor, and an anti-inflammatory agent," says corresponding author Jintae Lee of Yeungnam University, Gyeongsan, Korea.
E. coli O157:H7 causes hemorrhages in the intestine. To date, no effective therapy for O157:H7 biofilms has been found. Biofilms generally are notoriously resistant to antimicrobial therapy. So in the study, Lee screened a dozen flavonoids, including phloretin, for their ability to inhibit these biofilms. "We found that phloretin markedly reduced E. coli O157:H7 biofilm formation on abiotic surface and human colon epithelial cells, while phloretin did not harm commensal E. coli K-12 biofilms," says Lee. Commensal E. coli can actually fortify the human immune system, he says.
In addition to its anti- E. coli O157:H7 biofilm activity, phloretin "accounts in part for the antioxidant capacity of apples, and it also shows anti-inflammatory activity," says Lee. "This study suggests that phloretin in apples could reduce the risk of E. coli O157:H7 infection and intestinal inflammation."
"This study demonstrated for the first time that phloretin, a natural flavonoid, is a nontoxic inhibitor of enterohemorrhagic E. coli O157:H7 biofilms, but does not harm commensal E. coli K-12 biofilms," Lee writes. "Also, importantly, our results confirmed that phloretin shows anti-inflammatory properties in both the in vitro and in vivo inflammatory colitis models. The effect of phloretin was noticeably more pronounced than that of the conventional [inflammatory bowel disease] drug 5-aminosalicylic acid."
Everyone has heard the old adage, "an apple a day keeps the doctor away." We all know we should eat more fruit. But why apples? Do they contain specific benefits?
According to Dr. Bahram H. Arjmandi, PhD, RD, Margaret A. Sitton Professor and Chair, Department of Nutrition, Food and Exercise Sciences at The Florida State University, apples are truly a "miracle fruit" that convey benefits beyond fiber content. Animal studies have shown that apple pectin and polyphenols in apple improve lipid metabolism and lower the production of pro-inflammatory molecules. Arjmandi's most recent research is the first to evaluate the long-term cardioprotective effects of daily consumption of apple in postmenopausal women. The results of this USDA-funded study will be presented at Experimental Biology 2011 on Tuesday, April 12, at 12:45 pm in Washington, DC.
This study randomly assigned 160 women ages 45-65 to one of two dietary intervention groups: one received dried apples daily (75g/day for 1 year) and the other group ate dried prunes every day for a year. Blood samples were taken at 3, 6 and 12-months. The results surprised Dr. Arjmandi, who stated that "incredible changes in the apple-eating women happened by 6 months- they experienced a 23% decrease in LDL cholesterol," which is known as the "bad cholesterol." The daily apple consumption also led to a lowering of lipid hydroperoxide levels and C-reactive protein in those women.
"I never expected apple consumption to reduce bad cholesterol to this extent while increasing HDL cholesterol or good cholesterol by about 4%," Arjmandi said. Yet another advantage is that the extra 240 calories per day consumed from the dried apple did not lead to weight gain in the women; in fact, they lost on average 3.3 lbs. "Reducing body weight is an added benefit to daily apple intake" he said. Part of the reason for the weight loss could be the fruit's pectin, which is known to have a satiety effect. The next step in confirming the results of this study is a multi-investigator nationwide study.
There is frequently some truth behind our common expressions, and in the case of 'an apple a day,' Dr. Arjmandi has shown that nutrition science backs up the expression. "Everyone can benefit from consuming apples," he said.
An Apple Peel a Day Could Keep Cancer at Bay
An apple peel a day might help keep cancer at bay, according to Rui Hai Liu, Cornell associate professor of food science, who has identified a dozen compounds -- triterpenoids -- in apple peel that either inhibit or kill cancer cells in laboratory cultures. Three of the compounds have not previously been described in the literature.
"We found that several compounds have potent anti-proliferative activities against human liver, colon and breast cancer cells and may be partially responsible for the anti-cancer activities of whole apples," says Liu, who is affiliated with Cornell's Institute of Comparative and Environmental Toxicology and is senior author of the study, which is online and published in the Journal of Agricultural and Food Chemistry.
In previous Cornell studies, apples had been found not only to fight cancer cells in the laboratory but also to reduce the number and size of mammary tumors in rats. The Cornell researchers now think that the triterpenoids may be doing much of the anti-cancer work.
"Some compounds were more potent and acted differently against the various cancer cell lines, but they all show very potent anti-cancer activities and should be studied further," says Liu.
With co-author Xiangjiu He, a Cornell postdoctoral researcher, Liu analyzed the peel from 230 pounds of red delicious apples from the Cornell Orchard and isolated their individual compounds. After identifying the structures of the promising compounds in the peel, the researchers tested the pure compounds against cancer cell growth in the laboratory. In the past, Liu has also identified compounds called phytochemicals -- mainly flavonoids and phenolic acids -- in apples and other foods that appear to be have anti-cancer properties as well, including inhibiting tumor growth in human breast cancer cells.
"We believe that a recommendation that consumers to eat five to 12 servings of a wide variety of fruits and vegetables daily is appropriate to reduce the risks of chronic diseases, including cancer, and to meet nutrient requirements for optimum health," said Liu.
The study online: http://pubs.acs.org/cgi-bin/abstract.cgi/jafcau/2007/55/i11/abs/jf063563o.html
Adults who eat apples, drink apple juice have lower risk for metabolic syndrome
Apple product consumers likely to have lower blood pressure, trimmer waistlines, and more nutrient dense diets
Not eating your apple a day" Perhaps you should be. Adults who eat apples, apple juice and applesauce have a significantly reduced risk of metabolic syndrome, a cluster of health problems that are linked to numerous chronic diseases such as diabetes and cardiovascular disease.
The study results, presented at the Experimental Biology 2008 meeting this week, were derived from an analysis of adult food consumption data collected in the 1999-2004 National Health and Nutrition Examination Survey (NHANES), the government’s largest food consumption and health database.
Dr. Victor Fulgoni analyzed the data, specifically looking at the association between consumption of apples and apple products, nutrient intake and various physiological parameters related to metabolic syndrome. When compared to non-consumers, adult apple product consumers had a 27% decreased likelihood of being diagnosed with metabolic syndrome.
Fulgoni notes, “We found that adults who eat apples and apple products have smaller waistlines that indicate less abdominal fat, lower blood pressure and a reduced risk for developing what is known as the metabolic syndrome.”
In addition to having a 30% decreased likelihood for elevated diastolic blood pressure and a 36% decreased likelihood for elevated systolic blood pressure, apple product consumers also had a 21% reduced risk of increased waist circumference – all predictors of cardiovascular disease and an increased likelihood of metabolic syndrome. Additionally, adult apple product consumers had significantly reduced C-reactive protein levels, another measurable marker related to cardiovascular risk.
Furthermore, apple product consumers’ diets were healthier than non-consumers – they had an overall greater intake of fruit and key nutrients, including dietary fiber, vitamins A and C, calcium and potassium. These consumers also ate less total fat, saturated fat, discretionary fat and added sugars.
Apple pectin, apple juice extracts shown to have anticarcinogenic effects on colon
The apples and apple juice you consume may have positive effects in one of the most unlikely places in the body – in the colon. New research has demonstrated that both apple pectin and polyphenol-rich apple juice components actually enhance biological mechanisms that produce anticarcinogenic compounds during the fermentation process.
Using human fecal matter as the test substance, German researchers Dr. Dieter Schrenk, M.D. and his colleagues hypothesized that the compound butyrate could be increased in the presence of apple pectin and apple juice extracts.
Butyrate has been suggested to be a chemopreventative metabolite that might prevent the occurrence of colorectal cancer, which is very common in Western industrialized countries. It is a short chain fatty acid which is seen as a major factor contributing to healthy colon mucosa. The research notes, “Butyrate not only serves as a major nutrient for the colon epithelia but is also thought to play an important role in the protective effect of natural fiber against colorectal cancer.”
So how do apple pectin and apple juice extracts play a role in increasing amounts of butyrate? The laboratory tests performed by Schrenk found that by the increased production of butyrate via the addition of apple components, histone deacetlyases (HDAC) were inhibited. With slowed production of HDAC, there would be significantly less growth of precancerous and tumor cells.
The research, published in the April 2008 issue of Nutrition, notes, “apples are a major source of natural fiber and of low molecular weight plan polyphenols in the Western diet.” The researchers conclude, “Pectin-rich apple products can thus be expected to exert anticarginogenic effects in the colon.”
Apple consumers reap heart-health benefits
Apple consumers reap heart-health benefits thanks to flavonoid content, says new research
American Heart Association new recommendations support increased fruit, vegetable consumption
Apples may prove to be a winner when it comes to reducing the risk of heart disease, says a new study of more than 34,000 women. In this study, flavonoid-rich apples were found to be one of three foods (along with red wine and pears) that decrease the risk of mortality for both coronary heart disease (CHD) and cardiovascular disease (CVD) among post-menopausal women, The findings were published in the March 2007 American Journal of Clinical Nutrition.
Women of all ages are encouraged to consume more fruit and vegetables, including apples and apple products, for heart health. However, this study focused on postmenopausal woman, a group becoming more aware of the risk for heart disease. Using a government database that assesses the flavonoid-compound content of foods, the researchers hypothesized that flavonoid intake (in general and from specific foods), might be inversely associated with mortality from CVD and CHD among the women in the study groupSubjects selected for this research analysis were postmenopausal and part of the ongoing Iowa Women's Health Study, each of which has been monitored for dietary intake and various health outcomes for nearly 20 years.
As a result of the extensive analysis that considered what the women ate, the types of cardiovascular-related diseases they experienced, and the overall flavonoid content of an extensive list of foods, the researchers concluded that consumption of apples, pears and red wine were linked with the lowest risk for mortality related to both CHD and CVD (not just one or the other).
"Flavonoids are compounds found in small quantities in numerous plant foods, including fruits and vegetables, tea, wine, nuts and seeds, and herbs and spices," say the university researchers from the University of Minnesota and the University of Oslo (Norway) Earlier research has indicated that flavonoids also have antioxidant properties that are linked to the reduction of oxidation of the bad (LDL - low density lipoprotein) cholesterol which have been linked in various ways with the development of CVD. According to the government database cited in this paper, apples contain a wide variety of flavonoid compounds.
The researchers also believe this is the first prospective study of postmenopausal women to report on the intake and impact of total and specific flavonoid subclasses. They conclude, "Dietary intakes of flavanones, anthocyanins, and certain foods rich in flavonoids were associated with reduced risk of death due to CHD, CVD and all causes."_
The publication of this positive study for apples comes on the heels of updated heart disease prevention guidelines for women just released by the American Heart Association in the February 20 issue of Circulation. As part of their guidelines, AHA emphasizes that women increase their intake of fruits and vegetables to help prevent heart disease over their lifetime, not just to reduce short-term risk. Worldwide, cardiovascular disease is the largest single cause of mortality among women, accounting for one third of all deaths.
Can an apple a day keep asthma away?
Poor diets show increased respiratory symptoms in teens
Teenagers who forego a healthy and balanced diet may have a harder time catching their breath. A new study, published in the July issue of CHEST, the peer-reviewed journal of the American College of Chest Physicians (ACCP), shows that a low dietary intake of certain nutrients increases the likelihood of respiratory symptoms such as asthma, especially in teens who smoke. Furthermore, a lack of these nutrients may also lead to lower lung function.
“Our study, as well as other research, suggests that higher intakes of antioxidant and anti-inflammatory micronutrients are associated with lower reports of cough, respiratory infections, and less severe asthma-related symptoms,” said lead study author Jane Burns, ScD, Harvard School of Public Health. “Teenagers who have low dietary intakes of fruit, vitamin E, and omega-3 fatty acids are at greater risk of having asthma, emphasizing the importance of a balanced diet, composed of whole foods.”
While observing 12th-grade students from 12 communities around the US and Canada, Dr. Burns and her colleagues from the Harvard School of Public Health, Health Canada, Brigham and Women’s Hospital, and the Environmental Protection Agency (EPA), examined the associations of low dietary nutrient intake with low pulmonary function and respiratory symptoms. Over the period of one school year, 2,112 students completed a standardized respiratory questionnaire and a dietary questionnaire. They also answered questions about medication use, smoking habits, and recent exercise, before participating in lung function testing. Dr. Burns explained that the researchers focused on teens because it is the ideal age at which to test lung capacity and eating habits.
“During late adolescence, physical stature has, on average, been attained and lung growth closely parallels this growth. Therefore we were observing a time when lung function was close to its optimal capacity,” she said. “Also, although our diet survey targeted eating habits only during the past year, it did give us some idea of the teens’ general past diet. However, their current respiratory health may be a reflection of diet during childhood, as well as during the past year.”
The majority of adolescents in the study were white, one third was overweight, and 72% did not consume multivitamins. Also, nearly 25% reported smoking on a daily basis. Researchers also found that at least one third of the students’ diets were below the recommended levels of fruit, vegetable, vitamins A and E, beta-carotene, and omega-3 fatty acid intake.
“Vitamin supplements can help teens meet their daily recommended levels,” said Dr. Burns, “and surprisingly, even relatively low levels of omega-3 fatty acids appeared to protect teens from higher reported respiratory symptoms.”
Results showed that low dietary intakes of fruit, vitamins C and E, and omega-3 fatty acids were associated with decreased lung function and a greater risk of chronic bronchitic symptoms, wheeze, and asthma. These risks were further increased among students with the lowest intakes and who also smoked.
“I wish we could say that an apple a day can keep asthma away, but it’s a complex disease with a genetic component. However, it may be that certain foods can lessen or prevent asthma symptoms,” said Dr. Burns. “The most important thing to remember is that diet can have a significant impact on teens’ respiratory health. I would encourage them to make healthy eating a part of their daily routine, and stress to them that smoking is bad.” Researchers emphasized that fresh fruits make for convenient snacks. They also suggest preparing a simple, daily family meal, as a method to promote both communication and good nutrition.
“A balanced diet is not only good for lung health, but for general health,” said Mark J. Rosen, MD, FCCP, President of the American College of Chest Physicians. “Parents and physicians should work together to monitor and maintain healthy diets and lifestyles for children of all ages.”
Apples, apple juice shown to prevent early atherosclerosis
A new study shows that apples and apple juice are playing the same health league as the often-touted purple grapes and grape juice. The study was published in the April 2008 issue of Molecular Nutrition and Food Research.
Researcher Kelly Decorde from the Universite Montpelier in France was part of the European research team that found apples have similar cardiovascular protective properties to grapes. The researchers also observed that processing the fruit into juice has the potential to increase the bioavailability of the naturally-occurring compounds and antioxidants found in the whole fruit.
Using a variety of established analytical techniques, aortic plaque was evaluated to determine the effectiveness in decreasing plaque that is associated with atherosclerosis.
According to the research, “This study demonstrates that processing apples and purple grapes into juice modifies the protective effect of their phenolics against diet induced oxidative stress and early atherosclerosis in hypercholesterolemic hamsters.”
Researchers also noted, “These results show for the first time that long-term consumption of antioxidants supplied by apples and purple grapes, especially phenolic compounds, prevents the development of atherosclerosis in hamsters, and that the processing can have a major impact on the potential health effects of a product.”
In summary, the researchers stated that their work would help provide encouragement that fruit and fruit juices may have significant clinical and public health relevance.
Apples, Apple Juice Lower Wheezing and Asthma Risk in Children
Published in the September 2007 issue of Thorax, the latest study finds that when women ate apples during pregnancy, researchers found a significant decrease in asthma and wheezing among their children when the children were followed over five years and reached five years of age.
This unique longitudinal study tracked dietary intake by 1253 mother-child pairs. According to the researchers that conducted medical evaluations for asthma and related symptoms (i.e., wheezing) in the children, they found no other association with decreased risk other than for apple consumption. The only other positive association found between prenatal food intake and risk reduction in the children was with fish intake by the mothers, for which the researchers found that children of mothers who ate fish had a lowered incidence of doctor-confirmed eczema.
A similar but different study published June 2007 also showed a link between apple juice consumption and a reduction in wheezing among children. That study was published in June’s European Respiratory Journal.
Among children who experienced what was characterized as “current wheeze” (where the child had wheezing or whistling in the chest in the last 12 months), there was a significant, dose response association between consumption of apple juice and a reduced incidence of the wheezing. The researchers found that drinking apple juice made from concentrate and consumption of bananas one or more times a day (compared to drinking apple juice or eating bananas less than once a month) was directly associated with improvement of wheezing occurences.
According to the authors of the Thorax paper, the protective effect from apples is attributable to their powerful phytochemical content, which includes flavonoids, isoflavonoids, and phenolic acids. Apples and apple products combined are the largest source of free phenolics in people’s diet in the US and in Europe.
The American Lung Association states that asthma remains a major public health concern. In 2003, approximately 20 million Americans had asthma and the condition accounted for an estimated 12.8 million lost school days in children. Asthma ranks within the top ten prevalent conditions causing limitation of activity and costs our nation $16.1 billion in health care costs annually.
Apple's benefits reach into the womb to fight asthma
Eating apples while pregnant may give new meaning to an apple a day keeping the doctor away. Compelling new research has concluded that mothers who eat apples during pregnancy may protect their children from developing asthma later in life. The study was published in Thorax online.
This unique longitudinal study tracked dietary intake by nearly 2000 pregnant women, then examined the effects of the maternal diet on airway development in more than 1200 of their children five years later. Among a wide variety of foods consumed and recorded by the pregnant women, the researchers concluded that the children of mothers who ate apples had a significantly reduced risk for the development of asthma and childhood wheezing.
This study focuses on medical evaluations for asthma and related symptoms (i.e., wheezing) when the children were five years old. As a result of the evaluations cited in this research, other than apples, there were no consistent associations found between prenatal consumption of a range of healthful foods and asthma in the 1253 children who were evaluated.
Children of mothers who ate apples during pregnancy were much less likely to exhibit symptoms of asthma (including wheezing), say the researchers who hail from institutions in The Netherlands and Scotland. These same researchers previously reported positive associations between maternal consumption of vitamins A, E, D and zinc with reduced risk of asthma, wheeze and eczema in children.
The only other positive association found between prenatal food intake and risk reduction in the children was with fish, for which the researchers found that children of mothers who ate fish had a lowered incidence of doctor-confirmed eczema.
According to the research, "The present study suggests beneficial associations between maternal apple intake during pregnancy and wheeze and asthma at age five years." They add that their findings "suggest an apple specific effect, possibly because of its phytochemical content, such as flavonoids." The research paper cites other related studies on apples, including those which found that "intake of apples as a significant source of flavonoids and other polyphenols has been beneficially associated with asthma, bronchial hypersensitivity, and lung function in adults."
In 2004, the National Center for Health Statistics reported that nine million U.S. children have been diagnosed with asthma at one point in their lives and four million children suffered from asthma attacks that year. Others suffer from "hidden asthma" – undetected or undiagnosed asthma, according the American Lung Association. The cost of this disease is great – statistics show asthma to be the third-ranking cause of hospitalization among children under 15 and is among the leading causes of school absenteeism.
Eating apples/fish helps vs asthma/allergies
Women who eat apples and fish during pregnancy may reduce the risk of their children developing asthma or allergic disease, suggests a new study presented at the American Thoracic Society 2007 International Conference, on Sunday, May 20.
The SEATON study, conducted at the University of Aberdeen, UK, found that the children of mothers who ate the most apples were less likely to ever have wheezed or have doctor-confirmed asthma at the age of 5 years, compared to children of mothers who had the lowest apple consumption. Children of mothers who ate fish once or more a week were less likely to have had eczema than children of mothers who never ate fish.
The study did not find any protective effect against asthma or allergic diseases from many other foods, including vegetables, fruit juice, citrus or kiwi fruit, whole grain products, fat from dairy products or margarine or other low-fat spreads.
The researchers studied 1212 children born to women who had filled out food questionnaires during their pregnancy. When the children were 5 years old, the mothers filled out a questionnaire about the children’s respiratory symptoms and allergies, as well as a questionnaire about their child’s food consumption.
The children were also given lung function and allergy tests. Previous studies in the same children have found evidence for protective effects of vitamin E and D and zinc during pregnancy in reducing the risk of children’s wheeze and asthma, notes researcher Saskia Willers, M.Sc. of Utrecht University in the Netherlands. If the new results are confirmed, she says, "recommendations on dietary modification during pregnancy may help to prevent childhood asthma and allergy."
Willers concludes that at least until age 5, a mother’s diet during pregnancy might be more influential on a child’s respiratory health than the child’s own diet. She notes that further study of this group of children will be needed to see whether the association with the mothers’ diet declines in older children, and if mothers’ and their childrens’ diets interact in older children.
Willers suggests that the beneficial effect of apples may come from powerful antioxidants called flavonoids, while fish’s protective effect may come from omega-3 fatty acids, which other studies have suggested have a protective effect on the heart and may have a protective effect in asthma. "Other studies have looked at individual nutrients’ effect on asthma in pregnancy, but our study looked at specific foods during pregnancy and the subsequent development of childhood asthma and allergies, which is quite new," Willers says. "Foods contain mixtures of nutrients that may contribute more than the sum of their parts."
Naturally-occurring apple compounds reduce risk of pancreatic cancer
Smokers benefit most from intake of 'hidden' plant nutrients
Eating flavonol-rich foods like apples may help reduce the risk of pancreatic cancer, says a team of international researchers. Quercetin, which is found naturally in apples and onions, has been identified as one of the most beneficial flavonols in preventing and reducing the risk of pancreatic cancer. Although the overall risk was reduced among the study participants, smokers who consumed foods rich in flavonols had a significantly greater risk reduction.
This study, published in the October 15 issue of the American Journal of Epidemiology, is the first of its kind to evaluate the effect of flavonols – compounds found specifically in plants – on developing pancreatic cancer. According to the research paper, “only a few prospective studies have investigated flavonols as risk factors for cancer, none of which has included pancreatic cancer. “
Researchers from Germany, the Univ. of Hawaii and Univ. of Southern California tracked food intake and health outcomes of 183,518 participants in the Multiethnic Cohort Study for eight years. The study evaluated the participants’ food consumption and calculated the intake of the three flavonols quercetin, kaempferol, and myricetin. The analyses determined that flavonol intake does have an impact on the risk for developing pancreatic cancer.
The most significant finding was among smokers. Smokers with the lowest intake of flavonols presented with the most pancreatic cancer. Smoking is an established risk factor for the often fatal pancreatic cancer, notes the research.
Among the other findings were that women had the highest intake of total flavonols and seventy percent of the flavonol intake came from quercetin, linked to apple and onion consumption.
It is believed that these compounds may have anticancer effects due to their ability to reduce oxidative stress and alter other cellular functions related to cancer development.
“Unlike many of the dietary components, flavonols are concentrated in specific foods rather than in broader food groups, for example, in apples rather than in all fruit,” notes the research study. Previously, the most consistent inverse association was found between flavonols, especially quercetin in apples and lung cancer, as pointed out in this study. No other epidemiological flavonol studies have included evaluation of pancreatic cancer.
While found in many plants, flavonols are found in high concentrations in apples, onions, tea, berries, kale, and broccoli. Quercetin is most plentiful in apples and onions.
Compound in Apples Inhibits E. coli
A compound that is abundant in apples and strawberries inhibits the highly pathogenic E. coli O157:H7 biofilms while sparing a beneficial strain of E. coli that also forms biofilms in the human gut, according to a paper in the December 2011 issue of the journal Infection and Immunology.
Transcriptome analysis revealed that the compound, called phloretin, suppresses toxin and other genes involved in O157:H7 pathology and biofilm formation. And in a rat model of colitis, phloretin, reduced colon inflammation and body weight loss. "Phloretin has a triple biological activity as an antioxidant compound, a biofilm inhibitor, and an anti-inflammatory agent," says corresponding author Jintae Lee of Yeungnam University, Gyeongsan, Korea.
E. coli O157:H7 causes hemorrhages in the intestine. To date, no effective therapy for O157:H7 biofilms has been found. Biofilms generally are notoriously resistant to antimicrobial therapy. So in the study, Lee screened a dozen flavonoids, including phloretin, for their ability to inhibit these biofilms. "We found that phloretin markedly reduced E. coli O157:H7 biofilm formation on abiotic surface and human colon epithelial cells, while phloretin did not harm commensal E. coli K-12 biofilms," says Lee. Commensal E. coli can actually fortify the human immune system, he says.
In addition to its anti- E. coli O157:H7 biofilm activity, phloretin "accounts in part for the antioxidant capacity of apples, and it also shows anti-inflammatory activity," says Lee. "This study suggests that phloretin in apples could reduce the risk of E. coli O157:H7 infection and intestinal inflammation."
"This study demonstrated for the first time that phloretin, a natural flavonoid, is a nontoxic inhibitor of enterohemorrhagic E. coli O157:H7 biofilms, but does not harm commensal E. coli K-12 biofilms," Lee writes. "Also, importantly, our results confirmed that phloretin shows anti-inflammatory properties in both the in vitro and in vivo inflammatory colitis models. The effect of phloretin was noticeably more pronounced than that of the conventional [inflammatory bowel disease] drug 5-aminosalicylic acid."
Friday, February 17, 2012
Vitamin B and omega-3 supplementation and cancer: New data
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Researchers from the Nutritional Epidemiology Joint Research Unit have just published a study showing that, in men with a previous history of cardiovascular pathologies, supplementation with B vitamins and omega-3 polyunsaturated fatty acids did not significantly increase the occurrence of cancer.
However, women with a previous history of cardiovascular pathologies seem to have a higher cancer risk after five years of supplementation. The research is published in detail in the Archives of Internal Medicine.
Although some studies have suggested that supplementation with B vitamins has some benefits for protecting against cancer, the few randomised clinical trials conducted internationally in recent years remain equivocal.
The results of studies of the influence of supplementation with polyunsaturated fatty acids have been mixed.
That is why Valentina Andreeva and Pilar Galan and their staff wanted to study the effects of B vitamins and omega-3 polyunsaturated fatty acids (PUFAs) on cancer by monitoring, for five years from 2003 to 2009, more than 2500 people aged between 45 and 80 who had survived a heart attack, stroke or angina in the last 12 months.
The aim of the trial was to check the hypothesis that supplementation with en5-methyl-THF (and vitamins B6 and B12) and/or omega-3 was of value in preventing the recurrence of ischaemic pathologies in subjects who had suffered a heart attack or stroke.
The results, published this week in the Archives of Internal Medicine, are the outcome of a specific analysis performed as part of the intervention study SU.FOL.OM3, the results of which were published in 2010 in the British Medical Journal
SU.FOL.OM3 is a randomised double-blind placebo-controlled secondary prevention trial in which participants aged from 45 to 80 years with a previous history of cardiovascular pathologies were given daily supplements for five years of B vitamins (3 mg of vitamin B6, 560 μg of folates and 20 μg of vitamin B12) and/or omega-3 PUFAs (600 mg of eicosapentaenoic acid, EPA, and docosapentaenoic acid, DHA, in a ratio of 2:1), according to a factorial design.
It tested the effect of supplementation on cancer development over the five-year monitoring period in 145 men and 29 women.
All types of cancer were monitored
"Despite the low numbers, the results are significant," the authors believe, because the "methodology used – a randomised double-blind trial – is stringent".
The researchers conclude that "Neither B vitamin supplementation nor omega-3 PUFA supplementation has a significant effect on the occurrence of cancer in men. However, women receiving omega-3 fatty acids tended to present a higher risk of cancer compared with the placebo group (adjusted HR =3.02; CI of 95 % = [1.33; 6.89]). Although the underlying mechanisms are not clear, a potential mediating effect on the metabolism of oestrogens is suggested," they add.
To confirm or contradict these results, it is necessary to await new studies: randomised trials, cohort studies and mechanistic studies.
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Researchers from the Nutritional Epidemiology Joint Research Unit have just published a study showing that, in men with a previous history of cardiovascular pathologies, supplementation with B vitamins and omega-3 polyunsaturated fatty acids did not significantly increase the occurrence of cancer.
However, women with a previous history of cardiovascular pathologies seem to have a higher cancer risk after five years of supplementation. The research is published in detail in the Archives of Internal Medicine.
Although some studies have suggested that supplementation with B vitamins has some benefits for protecting against cancer, the few randomised clinical trials conducted internationally in recent years remain equivocal.
The results of studies of the influence of supplementation with polyunsaturated fatty acids have been mixed.
That is why Valentina Andreeva and Pilar Galan and their staff wanted to study the effects of B vitamins and omega-3 polyunsaturated fatty acids (PUFAs) on cancer by monitoring, for five years from 2003 to 2009, more than 2500 people aged between 45 and 80 who had survived a heart attack, stroke or angina in the last 12 months.
The aim of the trial was to check the hypothesis that supplementation with en5-methyl-THF (and vitamins B6 and B12) and/or omega-3 was of value in preventing the recurrence of ischaemic pathologies in subjects who had suffered a heart attack or stroke.
The results, published this week in the Archives of Internal Medicine, are the outcome of a specific analysis performed as part of the intervention study SU.FOL.OM3, the results of which were published in 2010 in the British Medical Journal
SU.FOL.OM3 is a randomised double-blind placebo-controlled secondary prevention trial in which participants aged from 45 to 80 years with a previous history of cardiovascular pathologies were given daily supplements for five years of B vitamins (3 mg of vitamin B6, 560 μg of folates and 20 μg of vitamin B12) and/or omega-3 PUFAs (600 mg of eicosapentaenoic acid, EPA, and docosapentaenoic acid, DHA, in a ratio of 2:1), according to a factorial design.
It tested the effect of supplementation on cancer development over the five-year monitoring period in 145 men and 29 women.
All types of cancer were monitored
"Despite the low numbers, the results are significant," the authors believe, because the "methodology used – a randomised double-blind trial – is stringent".
The researchers conclude that "Neither B vitamin supplementation nor omega-3 PUFA supplementation has a significant effect on the occurrence of cancer in men. However, women receiving omega-3 fatty acids tended to present a higher risk of cancer compared with the placebo group (adjusted HR =3.02; CI of 95 % = [1.33; 6.89]). Although the underlying mechanisms are not clear, a potential mediating effect on the metabolism of oestrogens is suggested," they add.
To confirm or contradict these results, it is necessary to await new studies: randomised trials, cohort studies and mechanistic studies.
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Cranky today? Even mild dehydration can alter our moods
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Most people only think about drinking water when they are thirsty; but by then it may already be too late.
Even mild dehydration can alter a person's mood, energy level, and ability to think clearly, according to two studies recently conducted at the University of Connecticut's Human Performance Laboratory.
The tests showed that it didn't matter if a person had just walked for 40 minutes on a treadmill or was sitting at rest – the adverse effects from mild dehydration were the same. Mild dehydration is defined as an approximately 1.5 percent loss in normal water volume in the body.
The test results affirm the importance of staying properly hydrated at all times and not just during exercise, extreme heat, or exertion, says Lawrence E. Armstrong, one of the studies' lead scientists and a professor of physiology in UConn's Department of Kinesiology in the Neag School of Education.
"Our thirst sensation doesn't really appear until we are 1 [percent] or 2 percent dehydrated. By then dehydration is already setting in and starting to impact how our mind and body perform," says Armstrong, an international expert on hydration who has conducted research in the field for more than 20 years. "Dehydration affects all people, and staying properly hydrated is just as important for those who work all day at a computer as it is for marathon runners, who can lose up to 8 percent of their body weight as water when they compete."
Separate groups of young women and men were tested. Twenty-five women took part in one study. Their average age was 23. The men's group consisted of 26 men with an average age of 20. All of the participants were healthy, active individuals, who were neither high-performance athletes nor sedentary – typically exercising for 30 to 60 minutes per day.
Each participant took part in three evaluations that were separated by 28 days. All of the participants walked on a treadmill to induce dehydration, and all of the subjects were hydrated the evening before the evaluations commenced. As part of the evaluation, the subjects were put through a battery of cognitive tests that measured vigilance, concentration, reaction time, learning, memory, and reasoning. The results were compared against a separate series of tests when the individuals were not dehydrated.
In the tests involving the young women, mild dehydration caused headaches, fatigue, and difficulty concentrating, according to one of the studies, which appears in the February issue of The Journal of Nutrition. The female subjects also perceived tasks as more difficult when slightly dehydrated, although there was no substantive reduction in their cognitive abilities.
In the tests involving the young men, mild dehydration caused some difficulty with mental tasks, particularly in the areas of vigilance and working memory, according to the results of the second UConn study. While the young men also experienced fatigue, tension, and anxiety when mildly dehydrated, adverse changes in mood and symptoms were "substantially greater in females than in males, both at rest and during exercise," according to the study. The men's study was published in the British Journal of Nutrition in November 2011.
"Even mild dehydration that can occur during the course of our ordinary daily activities can degrade how we are feeling – especially for women, who appear to be more susceptible to the adverse effects of low levels of dehydration than men," says Harris Lieberman, one of the studies' co-authors and a research psychologist with the Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine in Natick, Mass. "In both sexes these adverse mood changes may limit the motivation required to engage in even moderate aerobic exercise. Mild dehydration may also interfere with other daily activities, even when there is no physical demand component present."
Why women and men are so adversely affected by mild dehydration is unclear, and more research is necessary. But other research has shown that neurons in the brain detect dehydration and may signal other parts of the brain regulating mood when dehydration occurs. This process could be part of an ancient warning system protecting humans from more dire consequences, and alerting them to the need for water to survive.
In order to stay properly hydrated, experts like Armstrong recommend that individuals drink eight, 8-ounce glasses of water a day, which is approximately equivalent to about 2 liters of water. People can check their hydration status by monitoring the color of their urine. Urine should be a very pale yellow in individuals who are properly hydrated. Urine that is dark yellow or tan in color indicates greater dehydration. Proper hydration is particularly important for high-risk groups, such as the elderly, people with diabetes, and children.
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Most people only think about drinking water when they are thirsty; but by then it may already be too late.
Even mild dehydration can alter a person's mood, energy level, and ability to think clearly, according to two studies recently conducted at the University of Connecticut's Human Performance Laboratory.
The tests showed that it didn't matter if a person had just walked for 40 minutes on a treadmill or was sitting at rest – the adverse effects from mild dehydration were the same. Mild dehydration is defined as an approximately 1.5 percent loss in normal water volume in the body.
The test results affirm the importance of staying properly hydrated at all times and not just during exercise, extreme heat, or exertion, says Lawrence E. Armstrong, one of the studies' lead scientists and a professor of physiology in UConn's Department of Kinesiology in the Neag School of Education.
"Our thirst sensation doesn't really appear until we are 1 [percent] or 2 percent dehydrated. By then dehydration is already setting in and starting to impact how our mind and body perform," says Armstrong, an international expert on hydration who has conducted research in the field for more than 20 years. "Dehydration affects all people, and staying properly hydrated is just as important for those who work all day at a computer as it is for marathon runners, who can lose up to 8 percent of their body weight as water when they compete."
Separate groups of young women and men were tested. Twenty-five women took part in one study. Their average age was 23. The men's group consisted of 26 men with an average age of 20. All of the participants were healthy, active individuals, who were neither high-performance athletes nor sedentary – typically exercising for 30 to 60 minutes per day.
Each participant took part in three evaluations that were separated by 28 days. All of the participants walked on a treadmill to induce dehydration, and all of the subjects were hydrated the evening before the evaluations commenced. As part of the evaluation, the subjects were put through a battery of cognitive tests that measured vigilance, concentration, reaction time, learning, memory, and reasoning. The results were compared against a separate series of tests when the individuals were not dehydrated.
In the tests involving the young women, mild dehydration caused headaches, fatigue, and difficulty concentrating, according to one of the studies, which appears in the February issue of The Journal of Nutrition. The female subjects also perceived tasks as more difficult when slightly dehydrated, although there was no substantive reduction in their cognitive abilities.
In the tests involving the young men, mild dehydration caused some difficulty with mental tasks, particularly in the areas of vigilance and working memory, according to the results of the second UConn study. While the young men also experienced fatigue, tension, and anxiety when mildly dehydrated, adverse changes in mood and symptoms were "substantially greater in females than in males, both at rest and during exercise," according to the study. The men's study was published in the British Journal of Nutrition in November 2011.
"Even mild dehydration that can occur during the course of our ordinary daily activities can degrade how we are feeling – especially for women, who appear to be more susceptible to the adverse effects of low levels of dehydration than men," says Harris Lieberman, one of the studies' co-authors and a research psychologist with the Military Nutrition Division, U.S. Army Research Institute of Environmental Medicine in Natick, Mass. "In both sexes these adverse mood changes may limit the motivation required to engage in even moderate aerobic exercise. Mild dehydration may also interfere with other daily activities, even when there is no physical demand component present."
Why women and men are so adversely affected by mild dehydration is unclear, and more research is necessary. But other research has shown that neurons in the brain detect dehydration and may signal other parts of the brain regulating mood when dehydration occurs. This process could be part of an ancient warning system protecting humans from more dire consequences, and alerting them to the need for water to survive.
In order to stay properly hydrated, experts like Armstrong recommend that individuals drink eight, 8-ounce glasses of water a day, which is approximately equivalent to about 2 liters of water. People can check their hydration status by monitoring the color of their urine. Urine should be a very pale yellow in individuals who are properly hydrated. Urine that is dark yellow or tan in color indicates greater dehydration. Proper hydration is particularly important for high-risk groups, such as the elderly, people with diabetes, and children.
Ω
Thursday, February 16, 2012
Trouble Sleeping? It May Affect Your Memory Later On
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The amount and quality of sleep you get at night may affect your memory later in life, according to research that was recently released and will be presented at the American Academy of Neurology's 64th Annual Meeting in New Orleans April 21 to April 28, 2012.
"Disrupted sleep appears to be associated with the build-up of amyloid plaques, a hallmark marker of Alzheimer's disease, in the brains of people without memory problems," said study author Yo-El Ju, MD, with Washington University School of Medicine in St. Louis and a member of the American Academy of Neurology. "Further research is needed to determine why this is happening and whether sleep changes may predict cognitive decline."
Researchers tested the sleep patterns of 100 people between the ages of 45 and 80 who were free of dementia. Half of the group had a family history of Alzheimer's disease. A device was placed on the participants for two weeks to measure sleep. Sleep diaries and questionnaires were also analyzed by researchers.
After the study, it was discovered that 25 percent of the participants had evidence of amyloid plaques, which can appear years before the symptoms of Alzheimer's disease begin. The average time a person spent in bed during the study was about eight hours, but the average sleep time was 6.5 hours due to short awakenings in the night.
The study found that people who woke up more than five times per hour were more likely to have amyloid plaque build-up compared to people who didn't wake up as much. The study also found those people who slept "less efficiently" were more likely to have the markers of early stage Alzheimer's disease than those who slept more efficiently. In other words, those who spent less than 85 percent of their time in bed actually sleeping were more likely to have the markers than those who spent more than 85 percent of their time in bed actually sleeping.
"The association between disrupted sleep and amyloid plaques is intriguing, but the information from this study can't determine a cause-effect relationship or the direction of this relationship. We need longer-term studies, following individuals' sleep over years, to determine whether disrupted sleep leads to amyloid plaques, or whether brain changes in early Alzheimer's disease lead to changes in sleep," Ju said. "Our study lays the groundwork for investigating whether manipulating sleep is a possible strategy in the prevention or slowing of Alzheimer disease."
Ω
The amount and quality of sleep you get at night may affect your memory later in life, according to research that was recently released and will be presented at the American Academy of Neurology's 64th Annual Meeting in New Orleans April 21 to April 28, 2012.
"Disrupted sleep appears to be associated with the build-up of amyloid plaques, a hallmark marker of Alzheimer's disease, in the brains of people without memory problems," said study author Yo-El Ju, MD, with Washington University School of Medicine in St. Louis and a member of the American Academy of Neurology. "Further research is needed to determine why this is happening and whether sleep changes may predict cognitive decline."
Researchers tested the sleep patterns of 100 people between the ages of 45 and 80 who were free of dementia. Half of the group had a family history of Alzheimer's disease. A device was placed on the participants for two weeks to measure sleep. Sleep diaries and questionnaires were also analyzed by researchers.
After the study, it was discovered that 25 percent of the participants had evidence of amyloid plaques, which can appear years before the symptoms of Alzheimer's disease begin. The average time a person spent in bed during the study was about eight hours, but the average sleep time was 6.5 hours due to short awakenings in the night.
The study found that people who woke up more than five times per hour were more likely to have amyloid plaque build-up compared to people who didn't wake up as much. The study also found those people who slept "less efficiently" were more likely to have the markers of early stage Alzheimer's disease than those who slept more efficiently. In other words, those who spent less than 85 percent of their time in bed actually sleeping were more likely to have the markers than those who spent more than 85 percent of their time in bed actually sleeping.
"The association between disrupted sleep and amyloid plaques is intriguing, but the information from this study can't determine a cause-effect relationship or the direction of this relationship. We need longer-term studies, following individuals' sleep over years, to determine whether disrupted sleep leads to amyloid plaques, or whether brain changes in early Alzheimer's disease lead to changes in sleep," Ju said. "Our study lays the groundwork for investigating whether manipulating sleep is a possible strategy in the prevention or slowing of Alzheimer disease."
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