Thursday, February 28, 2013
Here's another reason why a healthy diet during pregnancy is critical to the future health of your children: New research published in the March 2013 issue of The FASEB Journal, suggests that pregnant mothers who consume junk food actually cause changes in the development of the opioid signaling pathway in the brains of their unborn children. This change results in the babies being less sensitive to opioids, which are released upon consumption of foods that are high in fat and sugar. In turn, these children, born with a higher "tolerance" to junk food need to eat more of it to achieve a "feel good" response.
"The results of this research will ultimately allow us to better inform pregnant women about the lasting effect their diet has on the development of their child's lifelong good preferences and risk of metabolic disease," said Beverly Muhlhausler, Ph.D., a researcher involved in the work from the FOODplus Research Centre at the School of Agriculture Food and Wine at The University of Adelaide in Adelaide, Australia. "Hopefully, this will encourage mothers to make healthier diet choices which will lead to healthier children."
To make this discovery, Muhlausler and colleagues studied the pups of two groups of rats, one of which had been fed a normal rat food and the other which had been fed a range of human "junk foods" during pregnancy and lactation. After weaning, the pups were given daily injections of an opioid receptor blocker, which blocks opioid signaling. Blocking opioid signaling lowers the intake of fat and sugar by preventing the release of dopamine. Results showed that the opioid receptor blocker was less effective at reducing fat and sugar intake in the pups of the junk food fed mothers, suggesting that the opioid signaling pathway in these offspring is less sensitive than for pups whose mothers are eating a standard rat feed.
"This study shows that addiction to junk food is true addiction." said Gerald Weissmann, M.D., Editor-in-Chief of The FASEB Journal. "Junk food engages the same body chemistry as opium, morphine or heroin. Sad to say, junk food during pregnancy turns the kids into junk food junkies."
Consuming omega-3 fish oils can help to prevent skin cancer, according to the first clinical trial exploring the influence of fish oils on the skin immunity of humans.
The study was conducted by a team of researchers from the University of Manchester and funded by the Association for International Cancer Research, and examined the effect of taking omega-3 on 79 healthy participants.
Findings of the study, published in The American Journal of Clinical Nutrition, revealed that consuming regular doses of fish oils increases immunity to sunlight.
It directly decreases sunlight-induced immunity suppression - called immunosuppression - which affects the body's power to combat skin cancer and infection.
Professor Lesley Rhodes, Professor of Experimental Dermatology from the Photobiology Unit Dermatology Centre at the University's School of Medicine and Salford Royal NHS Foundation Trust, said their study was the first of its kind conducted using humans:
"There has been research in this area carried out on mice in the past but this is the first time that there has been a clinical trial directly in people. It has taken a number of years to get to this stage and the findings are very exciting. This study adds to the evidence that omega-3 is a potential nutrient to protect against skin cancer. Although the changes we found when someone took the oil were small, they suggest that a continuous low level of chemoprevention from taking omega-3 could reduce the risk of skin cancer over an individual's lifetime."
The volunteers consumed a 4g dose of omega-3 - approximately one and a half portions of oily fish each day. Then they were exposed to either 8, 15, or 30 minutes of summer midday sun in Manchester using a specific light machine.
A number of other participants took a placebo before being exposed to the sunlight machine.
Immunosuppression was shown to be 50 percent lower in the subjects that took the omega-3 and were exposed to 8 and 15 minutes of sunshine compared with the volunteers who did not take the supplement. Little to no impact on those in the 30 minute group was shown.
The conclusions from this study are significant in the battle against skin cancer, because earlier studies have always shown that sunscreens are frequently applied incorrectly and only worn on vacation.
However, Professor Rhodes points out omega-3 is not a substitute for suntan lotion or physical protection, and that it should be seen as additional protection factor to help keep the skin from burning.
Historically, fish oil has already been associated with health benefits like protecting against cardiovascular disease, helping prevent age-related vision loss, and even slowing the growth of prostate cancer cells.
Tuesday, February 26, 2013
U.S. Preventive Services Task Force Recommendation Statement
The U.S. Preventive Services Task Force (USPSTF) makes recommendations about the effectiveness of specific clinical preventive services for patients without related signs or symptoms.
It bases its recommendations on the evidence of both the benefits and harms of the service and an assessment of the balance. The USPSTF does not consider the costs of providing a service in this assessment.
The USPSTF recognizes that clinical decisions involve more considerations than evidence alone. Clinicians should understand the evidence but individualize decision making to the specific patient or situation. Similarly, the USPSTF notes that policy and coverage decisions involve considerations in addition to the evidence of clinical benefits and harms.
Summary of Recommendations and Evidence
The USPSTF concludes that the current evidence is insufficient to assess the balance of the benefits and harms of combined vitamin D and calcium supplementation for the primary prevention of fractures in premenopausal women or in men (I statement).
The USPSTF concludes that the current evidence is insufficient to assess the balance of the benefits and harms of daily supplementation with greater than 400 IU of vitamin D3 and greater than 1,000 mg of calcium for the primary prevention of fractures in noninstitutionalized postmenopausal women (I statement).
The USPSTF recommends against daily supplementation with 400 IU or less of vitamin D3 and 1,000 mg or less of calcium for the primary prevention of fractures in noninstitutionalized postmenopausal women (D recommendation).
The USPSTF has previously concluded in a separate recommendation that vitamin D supplementation is effective in preventing falls in community-dwelling adults aged 65 years or older who are at increased risk for falls (B recommendation).
Fractures, particularly hip fractures, are associated with chronic pain and disability, loss of independence, decreased quality of life, and increased mortality (1). One half of all postmenopausal women will have an osteoporosis-related fracture during their lifetime.
Appropriate intake of vitamin D and calcium are essential to overall health. The Institute of Medicine has published recommended dietary allowances (Table). However, the benefits and harms of daily supplementation with greater than 400 IU of vitamin D3 and greater than 1,000 mg of calcium to prevent fractures are not clearly understood.
Benefits of Preventive Medication
In premenopausal women and in men, there is inadequate evidence to determine the effect of combined vitamin D3 and calcium supplementation on the incidence of fractures. In postmenopausal women, there is adequate evidence that daily supplementation with 400 IU of vitamin D3 combined with 1,000 mg of calcium has no effect on the incidence of fractures. However, there is inadequate evidence regarding the effect of higher doses of combined vitamin D and calcium supplementation on fracture incidence in noninstitutionalized postmenopausal women.
Harms of Preventive Medication
Adequate evidence indicates that supplementation with 400 IU or less of vitamin D3 and 1,000 mg or less of calcium increases the incidence of renal stones. The USPSTF assessed the magnitude of this harm as small.
Noninstitutionalized, community-dwelling postmenopausal women. The USPSTF concludes that evidence is lacking about the benefit of daily supplementation with greater than 400 IU of vitamin D3 and greater than 1,000 mg of calcium for the primary prevention of fractures, and the balance of benefits and harms cannot be determined.
The USPSTF concludes with moderate certainty that daily supplementation with 400 IU or less of vitamin D3 and 1,000 mg or less of calcium has no net benefit for the primary prevention of fractures.
Men and premenopausal women. The USPSTF concludes that evidence is lacking about the benefit of vitamin D supplementation with or without calcium for the primary prevention of fractures, and the balance of benefits and harms cannot be determined.
Results of the PREDIMED study, aimed at assessing the efficacy of the Mediterranean diet in the primary prevention of cardiovascular diseases, have been published in The New England Journal of Medicine. They show that the Mediterranean diet supplemented with extra-virgin olive oil or tree nuts reduces by 30 percent the risk of suffering a cardiovascular death, a myocardial infarction or a stroke.
The study has been coordinated by the researcher Ramon Estruch, from the Faculty of Medicine of the UB and the Hospital Clínic -- affiliated centres with the health campus of the UB, HUBc -- and has had the collaboration of the professor Rosa M. Lamuela and her team from the Natural Antioxidant Research Group of the Faculty of Pharmacy -- located at the campus of international excellence BKC -- which determined the biomarkers of Mediterranean diet consumption.
The research is part of the project PREDIMED, a multicentre trial carried out between 2003 and 2011 to study the effects of the Mediterranean diet on the primary prevention of cardiovascular diseases. The study was funded by the Carlos III Health Institute by means of the cooperative research thematic network (RETIC RD06/0045) and the CIBER of Physiopathology of Obesity and Nutrition (CIBERobn).
A total of 7,447 people with major cardiovascular risk factors participated in the study. They were divided into three dietary intervention groups: a Mediterranean diet supplemented with extra-virgin olive oil, a Mediterranean diet supplemented with nuts (walnuts, almonds, hazelnuts), and a low-fat diet (animal and vegetable). A dietician visited the patients every three months and they attended dietary training group sessions, in which they received detailed information about the Mediterranean and the low-fat diet, and the food included in each one. Moreover, they were provided with shopping lists, menus and recipes adapted to each type of diet and each season of the year.
During the study, those participants who followed any of the two types of Mediterranean diet received freely extra-virgin olive oil (one litre per week), and nuts (30 grams per day; 15 grams of walnuts, 7.5 grams of almonds and 7.5 grams of hazelnuts).
After five years, it has been proved that participants who followed any of the two types of Mediterranean diet showed a substantial reduction in the risk of suffering a cardiovascular death, a myocardial infarction or a stroke.
According to the researchers, the results of PREDIMED study are relevant as they prove that a high-vegetable fat diet is healthier at a cardiovascular level than a low-fat diet. The authors state that the study has been controversial as it provides new data to reject the idea that it is necessary to reduce fats in order to improve cardiovascular health.
Hopefully, these results will provide new references to prevent cardiovascular diseases. In addition, the design and methodology used can be easily transferred to the biomedical sector.
Monday, February 25, 2013
University of Kansas researchers have found that the infants of mothers who were given 600 milligrams of the omega-3 fatty acid DHA during pregnancy weighed more at birth and were less likely to be very low birth weight and born before 34 weeks gestation than infants of mothers who were given a placebo. This result greatly strengthens the case for using the dietary supplement during pregnancy.
The results are from the first five years of a 10-year, double-blind randomized controlled trial to be published in the April issue of the American Journal of Clinical Nutrition. It is also available online. A followup of this sample of infants is ongoing to determine whether prenatal DHA nutritional supplementation will benefit children’s intelligence and school readiness.
“A reduction in early preterm and very low birth weight delivery could have clear clinical and public health significance,” said Susan Carlson, A.J. Rice Professor of Dietetics and Nutrition at the KU Medical Center, who directed the study with John Colombo, KU professor of psychology and director of the Life Span Institute.
“We believe that supplementing U.S. women with DHA could safely increase mean birth weight and gestational age to numbers that are closer to other developed countries such as Norway and Australia,” she said.
DHA (docosahexaenoic acid) occurs naturally in cell membranes with the highest levels in brain cells, but levels can be increased by diet or supplements. An infant obtains DHA from his or her mother in utero and postnatally from human milk, but the amount received depends upon the mother’s DHA status.
“U.S. women typically consume less DHA than women in most of the developed world,” said Carlson.
During the first five years of the study, children of women enrolled in the study received multiple developmental assessments at regular intervals throughout infancy and at 18 months of age. In the next phase of the study, the children will receive twice-yearly assessments until they are 6 years old. The researchers will measure developmental milestones that occur in later childhood and are linked to lifelong health and welfare.
Previous research has established the effects of postnatal feeding of DHA on infant cognitive and intellectual development, but DHA is accumulated most rapidly in the fetal brain during pregnancy, said Colombo. “That’s why we are so interested in the effects of DHA taken prenatally, because we will really be able to see how this nutrient affects development over the long term.”
Saturday, February 23, 2013
Aspirin and omega-3 fatty acids work together to fight inflammation
OMEGA-3s Inhibit Breast Cancer Tumor Growth
A lifelong diet rich in omega-3 fatty acids can inhibit growth of breast cancer tumors by 30 per cent, according to new research from the University of Guelph. The study, published recently in the Journal of Nutritional Biochemistry, is believed to be the first to provide unequivocal evidence that omega-3s reduce cancer risk.
Study: Resveratrol shows promise to protect hearing, cognition
Resveratrol, a substance found in red grapes and red wine, may have the potential to protect against hearing and cognitive decline, according to a published laboratory study in the journal Otolaryngology-Head and Neck Surgery.
Diet high in glycemic index foods/dairy products =acne
A diet high in glycemic index foods and dairy products is now linked to acne, according to a new study published in the Journal of the Academy of Nutrition and Dietetics. The study also suggests using medical nutrition therapy (MNT) as a form of acne treatment. The findings support rising evidence of a link between diet and acne.
Eat a large variety of foods = healthiest sleep patterns
People who eat a large variety of foods, considered an indicator of a healthy diet, are also the ones with the healthiest sleep patterns, according to a new study in the journal Appetite.
A diet of resistant starch helps the body resist colorectal cancer
Resistant starch is found in peas, beans and other legumes, green bananas, and also in cooked and cooled starchy products like sushi rice and pasta salad. You have to consume it at room temperate or below – as soon as you heat it, the resistant starch is gone. But consumed correctly, it appears to kill pre-cancerous cells in the bowel
Coffee Drinking and Mortality?
A large study in the Journal of Caffeine Research of nearly half a million older adults followed for about 12 years revealed a clear trend: as coffee drinking increased, the risk of death decreased.
Sitting Time Associated With Increased Risk of Chronic Diseases
The more you sit, the higher your risk of chronic diseases says a study that is published in the International Journal of Behavioral Nutrition and Physical Activity.
Physical activity enhances cognition
Calcium Supplements May Raise Odds of Heart Death in Women
Folic acid supplements early in pregnancy may reduce child's risk of autism
Vitamin D Potency Varies Widely in Dietary Supplements
Vitamin D, Omega-3 May Help Clear Amyloid Plaques Found in Alzheimer's
Green Tea and Red Wine Extracts Interrupt Alzheimer's Disease Pathway in Cells
Southern diet could raise your risk of stroke
In the first large-scale study on the relationship between Southern foods and stroke, researchers characterized a Southern diet by a high intake of foods such as fried chicken, fried fish, fried potatoes, bacon, ham, liver and gizzards, and sugary drinks such as sweet tea. In addition to being high in fat, fried foods tend to be heavily salted.
Large Amounts of Vitamin C Increase Risk of Kidney Stones
Sunlight may help ward off rheumatoid arthritis in women
High supplemental calcium intake may increase risk of cardiovascular disease death in men
Low vitamin D levels may increase risk of Type 1 diabetes
Alcohol + diet drinks may increase intoxication
Olive oil component alleviates intestinal inflammation
Thursday, February 21, 2013
Experts tout the health benefits of low-dose aspirin and omega-3 fatty acids found in foods like flax seeds and salmon, but the detailed mechanisms involved in their effects are not fully known. Now researchers reporting in the February 21 issue of the Cell Press journal Chemistry & Biology show that aspirin helps trigger the production of molecules called resolvins that are naturally made by the body from omega-3 fatty acids. These resolvins shut off, or "resolve," the inflammation that underlies destructive conditions such as inflammatory lung disease, heart disease, and arthritis.
"In this report, we found that one resolvin, termed resolvin D3 from the omega-3 fatty acid DHA, persists longer at sites of inflammation than either resolvin D1 or resolvin D2 in the natural resolution of inflammation in mice," explains senior author Dr. Charles Serhan of Brigham and Women's Hospital and Harvard Medical School. "This finding suggests that this late resolution phase resolvin D3 might display unique properties in fighting uncontrolled inflammation."
The researchers also confirmed that aspirin treatment triggered the production of a longer acting form of resolvin D3 through a different pathway. "Aspirin is able to modify an inflammatory enzyme to stop forming molecules that propagate inflammation and instead produce molecules from omega-3 fatty acids, like resolvin D3, that help inflammation to end," explains coauthor Dr. Nicos Petasis of the University of Southern California.
A lifelong diet rich in omega-3 fatty acids can inhibit growth of breast cancer tumours by 30 per cent, according to new research from the University of Guelph.
The study, published recently in the Journal of Nutritional Biochemistry, is believed to be the first to provide unequivocal evidence that omega-3s reduce cancer risk.
“It’s a significant finding,” said David Ma, a professor in Guelph’s Department of Human Health and Nutritional Sciences, and one of the study’s authors.
“We show that lifelong exposure to omega-3s has a beneficial role in disease prevention – in this case, breast cancer prevention. What’s important is that we have proven that omega-3s are the driving force and not something else.”
Breast cancer remains the most common form of cancer in women worldwide and is the second leading cause of female cancer deaths.
Advocates have long believed diet may significantly help in preventing cancer. But epidemiological and experimental studies to back up such claims have been lacking, and human studies have been inconsistent, Ma said.
“There are inherent challenges in conducting and measuring diet in such studies, and it has hindered our ability to firmly establish linkages between dietary nutrients and cancer risk,” he said.
“So we’ve used modern genetic tools to address a classic nutritional question.”
For their study, the researchers created a novel transgenic mouse that both produces omega-3 fatty acids and develops aggressive mammary tumours. The team compared those animals to mice genetically engineered only to develop the same tumours.
“This model provides a purely genetic approach to investigate the effects of lifelong omega-3s exposure on breast cancer development,” Ma said.
“To our knowledge, no such approach has been used previously to investigate the role of omega-3s and breast cancer.”
Mice producing omega-3s developed only two-thirds as many tumours – and tumours were also 30-per-cent smaller – as compared to the control mice.
“The difference can be solely attributed to the presence of omega-3s in the transgenic mice – that’s significant,” Ma said.
“The fact that a food nutrient can have a significant effect on tumour development and growth is remarkable and has considerable implications in breast cancer prevention.”
Known as an expert in how fats influence health and disease, Ma hopes the study leads to more research on using diet to reduce cancer risk and on the benefits of healthy living.
“Prevention is an area of growing importance. We are working to build a better planet, and that includes better lifestyle and diet,” he said.
“The long-term consequences of reducing disease incidence can have a tremendous effect on the health-care system.”
Wednesday, February 20, 2013
Resveratrol, a substance found in red grapes and red wine, may have the potential to protect against hearing and cognitive decline, according to a published laboratory study from Henry Ford Hospital in Detroit.
The study shows that healthy rats are less likely to suffer the long-term effects of noise-induced hearing loss when given resveratrol before being exposed to loud noise for a long period of time.
"Our latest study focuses on resveratrol and its effect on bioinflammation, the body's response to injury and something that is believed to be the cause of many health problems including Alzheimer's disease, cancer, aging and hearing loss," says study lead author Michael D. Seidman, director of the Division of Otologic/Neurotologic Surgery in the Department of Otolaryngology-Head & Neck Surgery at Henry Ford Hospital.
"Resveratrol is a very powerful chemical that seems to protect against the body's inflammatory process as it relates to aging, cognition and hearing loss."
The study is published online this week ahead of print in the journal Otolaryngology-Head and Neck Surgery: http://oto.sagepub.com.
Hearing loss affects nearly one in five Americans. For most, hearing steadily declines with age. Noise-induced hearing loss, too, is a growing medical issue among American troops, with more than 12 percent returning home from Iraq and Afghanistan with significant hearing loss.
Noise-induced hearing loss not only impacts a person's ability to hear, it can cause difficulties with sleep and communication, and even raises the risk for heart disease by increasing a person's blood pressure, lipids and blood sugar.
Dr. Seidman and his colleagues have published multiple papers exploring noise-induced hearing loss, as well as the use of resveratrol, a grape constituent noted for its antioxidant and anti-inflammatory properties.
The latest study focuses the inflammatory process as it relates to aging, cognition and hearing loss.
It was designed to identify the potential protective mechanism of resveratrol following noise exposure by measuring its effect on cyclooxygenase-2 (or COX-2, key to the inflammatory process) protein expression and formation of reactive oxygen species, which plays an important role in cell signaling and homeostasis.
The study reveals that acoustic overstimulation causes a time-depended, up-regulation of COX-2 protein expression. And, resveratrol significantly reduces reactive oxygen species formation, inhibits COX-2 expression and reduces noise-induced hearing loss following noise exposure in rats.
"We've shown that by giving animals resveratrol, we can reduce the amount of hearing and cognitive decline," notes Dr. Seidman.
Ultimately, these findings suggest that resveratrol may exert a protective effect from noise-induced hearing loss by the inhibition of COX-2 expression and reactive oxygen species formation, although other mechanism may also be involved.
A diet high in glycemic index foods and dairy products is now linked to acne, according to a new study published in the Journal of the Academy of Nutrition and Dietetics.
The study also suggests using medical nutrition therapy (MNT) as a form of acne treatment. The findings support rising evidence of a link between diet and acne.
Over 17 million people in the United States have acne, which generally occurs during their teen and young adult years. Acne can affect quality of life and lead to:
* social withdraw
Because of these unfavorable consequences associated with the skin condition, treatment for acne is crucial.
Previous studies have always associated diet to this common skin condition. Since the 1800s, research pinpointed chocolate, sugar, and fat as diet factors contributing to acne. However, starting in the 1960s, studies began disassociating diet from acne.
Jennifer Burris, MS, RD, of the Department of Nutrition, Food Studies, and Public Health, Steinhardt School of Culture, Education, and Human Development, New York University said:
"This change occurred largely because of the results of two important research studies that are repeatedly cited in the literature and popular culture as evidence to refute the association between diet and acne. More recently, dermatologists and registered dietitians have revisited the diet-acne relationship and become increasingly interested in the role of medical nutritional therapy in acne treatment."
The researchers, led by Burris, conducted a literature review to examine evidence for the link between acne and diet during three time periods: early history, the rise of diet-acne myth, and recent studies.
The investigators took information from studies between 1960 and 2012 that examined acne and diet. The study factors that were analyzed were:
* intervention method
* results and conclusions
* primary outcome
* covariate considerations
The study showed that a high glycemic index/glycemic load diet and high dairy intake are the primary factors in establishing the association between acne and diet.
The researchers write about their findings in a paper that is available to read online, ahead of the May print issue of the journal Appetite.
First author Michael A. Grandner, Instructor in Psychiatry and member of the Center for Sleep and Circadian Neurobiology at Penn, says in a statement:
"Although many of us inherently recognize that there is a relationship between what we eat and how we sleep, there have been very few scientific studies that have explored this connection, especially in a real-world situation."
He says we already know from previous studies that in general, people who report sleeping between 7 and 8 hours of sleep a night are also the ones most likely to be in better health and feeling well, so he and his colleagues just wanted to know:
"Are there differences in the diet of those who report shorter sleep, longer sleep, or standard sleep patterns?"
The team looked for an answer by analyzing data from NHANES (short for National Health and Nutrition Examination Survey), an annual national survey that is sponsored by the Centers for Disease Control and Prevention (CDC).
The survey selects a representative sample of the US population, by age and demographics. The survey questions gather data about respondents' demographics, socioeconomic cicumstances, diet, and health.
Grandner describes what they found:
"Overall, people who sleep 7 - 8 hours each night differ in terms of their diet, compared to people who sleep less or more. We also found that short and long sleep are associated with lower food variety."
For their analysis, the team used data from the 2007-2008 NHANES, and focused on responses to questions about sleep and diet. They put the respondents into groups, depending on how much sleep they said they were getting each night.
The groups were: very short sleep (less than 5 hours a night), short sleep (5 to 6 hours a night) standard or normal sleep (7 to 8 hours a night), and long sleep (9 hours or more a night).
The NHANES data contains detailed information about respondents' daily diet, gathered in interviews with specially trained staff. This includes, for example, details about occasional glasses of water to comprehensive accounts of every part of each meal, allowing the researchers to calculate the nutrient and calorie intake of each of the sleep duration groups.
Diet Variations Linked to Sleep Patterns
Grandner and colleagues found that calorie intake varied across the groups, with short sleepers consuming the most calories, followed by normal sleepers, followed by very short sleepers, followed by long sleepers.
When they looked at food variety, they found this was highest in the normal sleep group and lowest in the very short sleep group.
There were differences among the groups in intake of proteins, carbohydrates, vitamins and minerals, but when the researchers analyzed these with statistical tools they found the differences were largely driven by a handful of key nutrients.
This analysis showed that, compared to the diet of the normal sleep group:
* Very short sleep was linked to less intake of tap water, lycopene (present in foods that are red and orange in colour, for instance tomatoes), and total carbohydrates.
* Short sleep was linked to lower intake of vitamin C, tap water, selenium (found in nuts, shellfish and meat), and higher intake of lutein/zeaxanthin (found in green, leafy vegetables).
* Long sleep was tied to lower intake of choline (found in eggs and fatty meats), theobromine (present in chocolate and tea), dodecanoic acid (a saturated fat) , and total carbohydrates, and a higher intake of alcohol.
These links remained even when they took into account other factors that might explain this relationship, such as demographics, socioeconomics, physical activity, and obesity.
Grandner points out that the study does not tell us, if people were to change their diet, would it affect their sleep pattern?
"This will be an important area to explore going forward as we know that short sleep duration is associated with weight gain and obesity, diabetes, and cardiovascular disease."
He says people who sleep too long also have health problems.
"If we can pinpoint the ideal mix of nutrients and calories to promote healthy sleep, the healthcare community has the potential to make a major dent in obesity and other cardiometabolic risk factors," he urges.
Tuesday, February 19, 2013
A large study of nearly half a million older adults followed for about 12 years revealed a clear trend: as coffee drinking increased, the risk of death decreased. Study author Neal Freedman, PhD, MPH, National Cancer Institute, discusses the significance of these findings and the potential links between coffee drinking, caffeine consumption, and various specific causes of disease in an interview in Journal of Caffeine Research, a peer-reviewed journal from Mary Ann Liebert, Inc., publishers. The article is available on the Journal of Caffeine Research website.
"Epidemiology of Caffeine Consumption and Association of Coffee Drinking with Total and Cause-specific Mortality" presents an in-depth interview exploring the many factors that could contribute to the association between coffee, disease, and mortality.
Dr. Freedman examines the relationship between coffee drinking and behaviors such as smoking and alcohol abuse, the physiological effects of caffeine on blood pressure and cardiac function, and the importance of differentiating between the effects of coffee and caffeine.
As the name suggests, you can’t digest resistant starch so it ends up in the bowel in pretty much the same form it entered your mouth. As unlovely as that seems, once in the bowel this resistant starch does some important things, including decreasing bowel pH and transit time, and increasing the production of short-chain fatty acids. These effects promote the growth of good bugs while keeping bad bugs at bay. A University of Colorado Cancer Center review published in this month’s issue of the journal Current Opinion in Gastroenterology shows that resistant starch also helps the body resist colorectal cancer through mechanisms including killing pre-cancerous cells and reducing inflammation that can otherwise promote cancer.
“Resistant starch is found in peas, beans and other legumes, green bananas, and also in cooked and cooled starchy products like sushi rice and pasta salad. You have to consume it at room temperate or below – as soon as you heat it, the resistant starch is gone. But consumed correctly, it appears to kill pre-cancerous cells in the bowel,” says Janine Higgins, PhD, CU Cancer Center investigator and associate professor of Pediatrics at the University of Colorado School of Medicine.
Higgins describes studies showing that rats fed resistant starch show decreased numbers and sizes of lesions due to colorectal cancer, and an increased number of cells that express the protein IL-10, which acts to regulate the body’s inflammatory response.
”Resistant starch may also have implications for the prevention of breast cancer,” Higgins says. “For example, if you let rats get obese, get them to lose the weight, and then feed half of the rats a diet high in resistant starch – these rats don’t gain back the weight as fast as rats fed a regular, digestible starch diet. This effect on obesity may help to reduce breast cancer risk as well as having implications for the treatment of colorectal cancer.”
“There are a lot of things that feed into the same model of resistant starch as a cancer-protective agent,” Higgins says. “Much of this information currently comes from rodent models and small clinical trials but the evidence is encouraging.” On the table now is a menu of benefits and while it’s just now being studied which benefits, exactly, will pan out as mechanisms of cancer prevention, one thing is clear: resistant starch should be on the menu.
The more you sit, the higher your risk of chronic diseases. Kansas State University researcher Richard Rosenkranz, assistant professor of human nutrition, examined the associations of sitting time and chronic diseases in middle-aged Australian males in a study that is published in the International Journal of Behavioral Nutrition and Physical Activity.
The study's sample included 63,048 males ages 45-65 from the Australian state of New South Wales. Study participants reported the presence or absence of various chronic diseases, along with their daily sitting time: categorized as less than four hours, four to six hours, six to eight hours, or more than eight hours.
Compared with those who reported sitting four hours or less per day, those who sat for more than four hours per day were significantly more likely to report having a chronic disease such as cancer, diabetes, heart disease and high blood pressure. The reporting of chronic diseases rose as participants indicated they sat more. Those sitting for at least six hours were significantly more likely to report having diabetes.
"We saw a steady stair-step increase in risk of chronic diseases the more participants sat," Rosenkranz said. "The group sitting more than eight hours clearly had the highest risk."
The study is relevant to office workers sitting at desks and those sitting for long periods of time such as truck drivers, he said.
"We know that with very high confidence that more physically active people do better with regard to chronic disease compared with less physically active people, but we should also be looking at reducing sitting," Rosenkranz said. "A lot of office jobs that require long periods of sitting may be hazardous to your health because of inactivity and the low levels of energy expenditure."
Researchers discovered consistent findings in those who had a similar physical activity level, age, income, education, weight and height. Participants who sat more reported more chronic diseases -- even if they had a similar body mass index compared with those who sat less.
In general, people should get more physical activity and sit less, Rosenkranz said.
"It's not just that people aren't getting enough physical activity, but it's that they're also sitting too much," he said. "And on top of that, the more you sit, the less time you have for physical activity."
The study focused on males, because they have higher rates of diabetes and heart disease, but it is probably applicable in adults across gender, race and ethnicity, Rosenkranz said. Little is known about children and sitting with regard to chronic disease.
The research is part of the 45 and Up Study, the largest long-term study of aging in Australia, involving more than 267,000 people.
Researchers said that although most of the current evidence is suggestive of a causal connection, they cannot be certain in this study whether volumes of sitting time led to the development of chronic diseases or whether the chronic diseases influenced sitting time.
"It's a classic case of, 'Which came first: The chicken or the egg?'" Rosenkranz said.
Maternal nutrition is important to a developing embryo and to the health of the child later in life. Supplementing the diet with specific vitamins is known to increase health of the fetus for example folic acid (vitamin B9) reduces the risk of spina bifida. However not everything an adult might consume is beneficial to a developing baby. New research published in BioMed Central's open access journal BMC Medicine shows that caffeine is linked to low birth weight babies and that caffeine from coffee in linked to increasing length of pregnancy.
Along with nutrients and oxygen, caffeine freely passes the placental barrier, but the developing embryo does not express the enzymes required to inactivate it efficiently. The WHO currently suggests a limit of 300mg per day during pregnancy but some countries recommend a limit of 200mg, which can be less than a single cup of coffee from some high street cafes.
To investigate the impact of maternal caffeine during pregnancy on babies, a research team from the Norwegian Institute for Public Health used information about mother's diet and birth details collected over ten years. After excluding women with medical and pregnancy-related conditions almost 60,000 pregnancies were included in the study. All sources of caffeine were monitored in the study: coffee, tea, fizzy drinks, as well as food including cocoa-containing cakes and deserts and chocolate.
Explaining their results, Dr Verena Sengpiel, from Sahlgrenska University Hospital, Sweden, who led the project said, "Although caffeine consumption is strongly correlated with smoking which is known to increase the risk for both preterm delivery and the baby being small for gestational age at birth (SGA). In this study we found no association between either total caffeine or coffee caffeine and preterm delivery but we did find an association between caffeine and SGA. This association remained even when we looked only at non-smoking mothers which implies that the caffeine itself is also having an effect on birth weight."
In fact they found that caffeine from all sources reduced birth weight. For a child of expected average weight (3.6kg) this equates to 21-28g lost per 100mg caffeine per day. But it was not just caffeine, but the source of caffeine, which affected pregnancy outcomes. Caffeine from all sources increased the length of the pregnancy by 5hr per 100mg caffeine per day, but caffeine intake from coffee was associated with an even longer gestational length -- 8hr extra for every 100mg caffeine per day.
This association means that it is not just the caffeine in coffee which increases gestational length but either there must be a substance in coffee which is responsible for the extra time or there is a behaviour associated with coffee drinking not present in women who drink only tea (for example). SGA babies are at higher risk of both short term and lifelong health problems and it seems from these results that since even 200-300mg caffeine per day can increase the risk of SGA by almost a third these recommendations need to be re-evaluated.
Monday, February 18, 2013
Exercise doesn't only strengthen your heart and muscles – it also beefs up your brain. Dozens of studies now show that aerobic exercise can increase the size of critical brain structures and improve cognition in children and older adults.
University of Illinois psychology professor Art Kramer, a nationally recognized expert on the role of physical fitness on cognition, will discuss these brain-changing outcomes at a session of the 2013 meeting of the American Association for the Advancement of Science in Boston on Feb. 16. Kramer is the director of the Beckman Institute for Advanced Science and Technology at the U. of I.
"Populations throughout the industrialized world are becoming increasing sedentary as a result of the changing nature of work and leisure activities," Kramer said. "As a result of these societal changes, increases in diseases such as hypertension, diabetes, osteoporosis and some cancers are increasing. Physical activity serves to reduce susceptibility to these diseases."
"Increased physical activity also has direct, and relatively rapid effects on cognition and brain health," he said. "Such results have now been reported, over the course of several decades, in animal studies of physical activity."
Studies in humans, many conducted in Kramer's lab, also show that regular exercise, such as walking three times per week, also increases brain power.
Kramer will present research from his own lab and others that demonstrates that older adults who participate in fitness training and physical activity benefit from significant improvements in their brain structure and function. He will detail how scientists use both behavioral measures and non-invasive neuroimaging techniques such as magnetic resonance imaging (MRI), functional MRI, event-related brain potential, and event-related optical signals to assess cognition. He will conclude his presentation with a dissection of the gaps present in human and animal cognitive and brain health literature and describe how future research can remedy this.
Thursday, February 14, 2013
Individuals who have a high preference for sweets and a high aversion to bitter flavors may be at an increased risk of developing metabolic syndrome, according to a new study in the Journal of Food Science, published by the Institute of Food Technologists (IFT).
Researchers at the University of North Carolina at Chapel Hill analyzed how two tasting profiles, sweet likers (SL) and supertasters (ST), interact and affect dietary intake and health, particularly metabolic syndrome. Metabolic syndrome is a name for a group of risk factors that occur together and increase the risk for coronary artery disease, stroke, and type-2 diabetes.
What researchers found is that those with both taste profiles or neither taste profiles were more likely to have an increased risk of metabolic syndrome compared to those who were only an SL or ST. The interaction between SL and ST was also significantly associated with fiber and beverage intake suggesting that tasting patterns may have an effect on both dietary intake and disease risk.
Wednesday, February 13, 2013
Women eating a high-calcium diet and taking calcium supplements adding up to more than 1,400 milligrams a day may be running nearly twice the risk of dying from heart disease, a large Swedish study suggests.
Both men and women take calcium supplements to prevent bone loss. The new findings come on the heels of another recent study that found a similar increased risk of death related to calcium intake among men.
"Many older adults increase dietary intake of calcium or take calcium supplements to prevent bone loss and there had been speculation that increased calcium intake with or without vitamin D could improve cardiovascular health," said Dr. Gregg Fonarow, an American Heart Association spokesman who wasn't involved in the study.
However, a number of recent studies have suggested that higher dietary intake or calcium supplementation may not only not improve cardiovascular health -- they may be associated with increased risk for cardiovascular events and mortality, said Fonarow, a professor of cardiology at University of California, Los Angeles.
The new report was published in the Feb. 12 online edition of the BMJ.
To see if calcium supplements raised the risk of dying from heart disease, a team led by Dr. Karl Michaelsson, a clinical professor in the department of orthopedic surgical sciences at Uppsala University in Sweden, analyzed data collected on more than 61,000 women enrolled in a study on mammograms.
Over 19 years of follow-up, nearly 12,000 women died -- almost 4,000 dying from cardiovascular disease, about 1,900 from heart disease and 1,100 from stroke, the researchers found.
The highest rates of death were seen among women whose calcium intake was higher than 1,400 milligrams a day, the researchers noted. On the other hand, women who took less than 600 milligrams of calcium a day were also at an increased risk of death.
Moreover, women taking 1,400 milligrams of calcium a day and also using a supplement had even a higher risk of dying than women not using supplements, Michaelsson's group found.
All in all, women getting more than 1,400 milligrams of calcium a day were more than twice as likely to die than women getting 600 to 999 milligrams a day, the researchers said.
The U.S. Office of Dietary Supplements recommends 1,000 to 1,200 milligrams of calcium a day for most adults.
According to the study authors, diets very low or very high in calcium can override normal control by the body, causing changes in blood levels of calcium.
Rather than worry about increasing calcium intake of those getting enough through their diet, emphasis should be placed on people with a low intake of calcium, the authors suggest.
Taylor Wallace, a representative of the supplement industry, faults this study because, he said, it was not specifically meant to address calcium supplements and heart disease.
"We are comparing apples and oranges," said Wallace, who is senior director for Scientific & Regulatory Affairs at the Council for Responsible Nutrition. He noted that in the new study, the data that researchers used to draw their conclusions looked at diet and cancer, not whether calcium supplements were bad for the heart.
"Still, there is not a single human cause-and-effect study that demonstrates a hazard for calcium either from the diet or supplements and cardiovascular disease," he said.
Although the new study tied total calcium intake to increased risk of death from heart disease in women, it didn't establish a cause-and-effect relationship.
Wallace did say it's important to know how much calcium a person is getting from diet and supplements. "It is important to talk with your doctor to make sure you are getting the right amount for you," he said.
For his part, heart association spokesman Fonarow said: "While further studies are needed, calcium supplements should be used only after careful consideration of whether the potential benefits in terms of bone health outweigh the potential cardiovascular risks."
Tuesday, February 12, 2013
Prenatal folic acid supplements appear to reduce the risk for autistic spectrum disorders, according to a study published today (February 13) in the Journal of the American Medical Association (JAMA).
The Centers for Disease Control and Prevention estimate that about 1 in 88 children in the U.S. have been identified with an Autism Spectrum Disorder (ASD). ASDs are amongst the most heritable of mental disorders, but little is known about how the disorder develops. Consequently, methods for diagnosis, prevention, and treatment are limited.
Folic acid (Vitamin B9) is required for DNA synthesis and repair in the human body, and its naturally occurring form—folate—is found in leafy vegetables, peas, lentils, beans, eggs, yeast, and liver. Taking folic acid supplements during early pregnancy is known to protect against spina bifida and other neural tube defects in children. In the United States, Canada, and Chile, folic acid is added to flour, so as to automatically provide these supplements to consumers. Norway does not enrich its flour, and since 1998, the Norwegian Directorate of Health has recommended that all women planning to become pregnant take a daily supplement of folic acid from one month before the start of pregnancy through the first trimester.
Despite this policy, studies from North America and Europe have shown that many pregnant women have a lower dietary intake of folate than what is necessary to prevent neural tube defects.
The report in JAMA emerged from the Norwegian Mother and Child Cohort Study (MoBa) and its sub-study of autism, the Autism Birth Cohort (ABC) Study. This international collaboration (see list of members below) comprises the largest prospective birth cohort devoted to the investigation of gene-environment interactions and biomarker discovery for neuropsychiatric disorders.
A total of 85,176 MoBa babies—born from 2002-2008—and their parents participated in the study. Prenatal dietary habits were recorded, and families were regularly surveyed for 3-10 years to measure the development of autism spectrum disorders. A total of 270 cases of autism spectrum disorders were identified in the study population (114 autistic disorder; 56 Asperger syndrome; 100 atypical or unspecified autism; i.e., pervasive developmental disorder not otherwise specified, PDD-NOS).
Mothers who took folic acid supplements in early pregnancy had a 40% reduced risk of having children with autistic disorder compared with mothers who did not take folic acid. The reduction in risk was observed in those who took folic acid during the time interval from 4 weeks before to 8 weeks after the start of pregnancy. Autistic disorder is the most severe form of autism spectrum disorders in children. No reduction in risk was observed for PDD-NOS. For Asperger syndrome, the number of children was too low to obtain sufficient statistical power in the analyses.
The use of folic acid in early pregnancy increased substantially from 2002 to 2008 among women who participated in MoBa. In 2002, 43% of mothers took folic acid supplements; by 2008, 85% of mothers did. However, many women began taking folic acid later than recommended, and only half started before the beginning of pregnancy.
The timing of a mother's intake of folate appears to be a critical factor. Her child's risk of autism was reduced only when the supplements were taken between 4 weeks before to 8 weeks after the start of pregnancy.
"We examined the rate of autism spectrum disorders in children born to mothers who did or did not take folic acid during pregnancy. There was a dramatic reduction in the risk of autistic disorder in children born to mothers who took folic acid supplements," says Pål Surén, first author and epidemiologist at the Norwegian Institute of Public Health (NIPH).
The researchers also analyzed whether the risk of autistic disorder was influenced by the use of other dietary supplements. They did not find any association between the mother's use of fish oil supplements (cod liver oil and omega-3 fatty acids) in early pregnancy and the risk of autistic disorder, and no association for the mother's use of other vitamins and minerals.
In recent years, researchers have started to investigate whether folic acid has other beneficial effects on the development of the fetus' brain and spinal cord. A study of language development from MoBa, published in 2011, showed that children whose mothers took folic acid supplements in early pregnancy had only half the risk of severe language delay at age three years compared with other children. A separate 2011 study from the University of California, Davis, demonstrated a lower risk of autism spectrum disorders in children of mothers who had used prenatal vitamin supplements during pregnancy. Prenatal vitamin supplements contain folic acid in combination with other vitamins and minerals.
Joint senior author Ezra Susser, professor of Epidemiology at Columbia University's Mailman School of Public Health and professor of Psychiatry at the College of Physicians and Surgeons, stated, "Our findings extend earlier work on the significance of folate in brain development and raise the possibility of an important and inexpensive public health intervention for reducing the burden of autism spectrum disorders."
"This elegant work illustrates the power of the ABC cohort for not only chipping away at the riddle of what causes autism, but for developing new methods for early recognition, prevention and treatment," says W. Ian Lipkin, John Snow Professor of Epidemiology at the Mailman School of Public Health and principal investigator of the ABC cohort.
Vitamin D supplement potency varies widely, and the amount of vitamin D in over-the-counter and compounded supplements does not necessarily match the amount listed on the label, according to a research letter published in the journal JAMA Internal Medicine.
The analysis showed that the amount of vitamin D in these supplements ranged from 9 percent to 146 percent of the amount listed on the label. Not only was there variation among different brands and manufacturers, but also among different pills from the same bottle.
"We were surprised by the variation in potency among these vitamin D pills," says Erin S. LeBlanc, MD, MPH, lead author and investigator with the Kaiser Permanente Center for Health Research in Portland, Ore. "The biggest worry is for someone who has low levels of vitamin D in their blood. If they are consistently taking a supplement with little vitamin D in it, they could face health risks."
According to a recent editorial in the New England Journal of Medicine, more than 100 million Americans spend a combined $28 billion on vitamins, herbs and supplements each year. The U.S. Food and Drug Administration is considering new safety guidelines for some supplements but, for the most part, the industry remains unregulated.
Some manufacturers participate in a voluntary quality verification program operated by the U.S. Pharmacopeial Convention -- an independent, nonprofit organization that sets public standards for the quality of dietary supplements. In order to receive the USP verification mark, manufacturers' facilities undergo annual good manufacturing-practice audits, and their products are tested for quality, potency and purity. Dr. LeBlanc and her colleagues included one supplement from a USP Verified manufacturer in their sample. They found the amount of vitamin D in pills from that bottle was generally more accurate than the other bottles tested.
"The USP verification mark may give consumers some reassurance that the amount of vitamin D in those pills is close to the amount listed on the label," said Dr. LeBlanc. "There are not many manufacturers that have the USP mark, but it may be worth the extra effort to look for it."
Thursday, February 7, 2013
According to the position paper: "In contrast to the total diet approach, classification of specific foods as 'good' or 'bad' is overly simplistic and may foster unhealthy eating behaviors." The Academy's position paper stresses that moderation, portion size and exercise are the key concepts for balancing food and beverage intakes.
The position paper has been published in the February Journal of the Academy of Nutrition and Dietetics and can be found on the Academy's website. It states:
It is the position of the Academy of Nutrition and Dietetics that the total diet or overall pattern of food eaten is the most important focus of healthy eating. All foods can fit within this pattern, if consumed in moderation with appropriate portion size and combined with physical activity. The Academy strives to communicate healthy eating messages that emphasize a balance of food and beverages within energy needs, rather than any one food or meal.The Academy's position paper has been updated to reflect the most current nutrition guidance, such as the 2010 Dietary Guidelines for Americans and the USDA's MyPlate food guidance system; the White House's Let's Move! campaign to reduce childhood obesity and Healthy People 2020. Each of these public policies and dietary patterns supports the total diet approach.
According to the position paper, while studies including the Academy's "Nutrition and You" national consumer survey show Americans are "conscious of the importance of healthy diets and physical activity," most people do not meet the recommendations of the Dietary Guidelines. For example, large majorities do not eat fruit (68 percent) or vegetables (74 percent) more than twice a day, and a substantial number (36 percent) engage in no leisure-time physical activity.
In that environment, according to the Academy: "Labeling specific foods in an overly simplistic manner as 'good foods' and 'bad foods' is not only inconsistent with the total diet approach, but it may cause many people to abandon efforts to make dietary improvements."
The position paper adds: "In 2011, 82 percent of U.S. adults cited not wanting to give up foods they like as a reason for not eating healthier. For these reasons, the concepts of moderation and proportionality are necessary components of a practical, action-oriented understanding of the total diet approach."
The Academy's position paper notes that the most recent Dietary Reference Intakes use a total diet approach because it allows for a broad range of foods to meet a person's nutrition needs over time. Therefore, a person can make diet choices based on individual preferences, genetic background, personal health status and food availability.
The position paper was written by registered dietitians Jeanne Freeland-Graves, Bess Heflin Centennial Professor in the department of nutritional sciences at the University of Texas -- Austin; and Susan Nitzke, professor emerita and extension specialist in nutritional sciences at the University of Wisconsin -- Madison.
The Academy's position paper contains advice and recommendations for health professionals as well as consumers. It explains how food and nutrition practitioners can use behavioral theories and models to develop effective nutrition communications; and how food and beverage choices are affected by multiple factors that influence people's ability to make use of expert advice on healthy eating.
Updated sections of the position paper look at new indicators of nutrient quality, such as the Nutrient Rich Food Index, the European Union Nutrient Profiling System and the Overall Nutrient Quality Index. In addition, the Social Ecological model, used in the Dietary Guidelines, is incorporated into the Academy's position as "a guide for understanding why we eat what we do."
According to the Academy's position paper: "Food and nutrition practitioners have a responsibility to communicate unbiased food and nutrition information that is culturally sensitive, scientifically accurate, medically appropriate and tailored to the needs and preferences of the target audience. Some health and nutrition professionals and many 'pseudo-experts' promote specific types of foods to choose or avoid. A more responsible and effective approach is to help consumers understand and apply the principles of healthy diet and lifestyle choices. Unless there are extenuating circumstances (severe cognitive or physical limitations), the total diet approach is preferred because it is more consistent with research on effective communication and inclusive of cultural/personal differences."
A team of academic researchers has pinpointed how vitamin D3 and omega-3 fatty acids may enhance the immune system's ability to clear the brain of amyloid plaques, one of the hallmarks of Alzheimer's disease.
In a small pilot study published in the Feb. 5 issue of the Journal of Alzheimer's Disease, the scientists identified key genes and signaling networks regulated by vitamin D3 and the omega-3 fatty acid DHA (docosahexaenoic acid) that may help control inflammation and improve plaque clearance.
Previous laboratory work by the team helped clarify key mechanisms involved in helping vitamin D3 clear amyloid-beta, the abnormal protein found in the plaque. The new study extends the previous findings with vitamin D3 and highlights the role of omega-3 DHA.
"Our new study sheds further light on a possible role for nutritional substances such as vitamin D3 and omega-3 in boosting immunity to help fight Alzheimer's," said study author Dr. Milan Fiala, a researcher at the David Geffen School of Medicine at UCLA.
For the study, scientists drew blood samples from both Alzheimer's patients and healthy controls, then isolated critical immune cells called macrophages from the blood. Macrophages are responsible for gobbling up amyloid-beta and other waste products in the brain and body.
The team incubated the immune cells overnight with amyloid-beta. They added either an active form of vitamin D3 called 1alpha,25–dihydroxyvitamin D3 or an active form of the omega-3 fatty acid DHA called resolvin D1 to some of the cells to gauge the effect they had on inflammation and amyloid-beta absorption.
Both 1alpha, 25-dihydroxyvitamin D3 and resolvin D1 improved the ability of the Alzheimer's disease patients' macrophages to gobble-up amyloid-beta, and they inhibited the cell death that is induced by amyloid-beta. Researchers observed that each nutrition molecule utilized different receptors and common signaling pathways to do this.
Previous work by the team, based on the function of Alzheimer's patients' macrophages, showed that there are two groups of patients and macrophages. In the current study, researchers found that the macrophages of the Alzheimer's patients differentially expressed inflammatory genes, compared with the healthy controls, and that two distinct transcription patterns were found that further define the two groups: Group 1 had an increased transcription of inflammatory genes, while Group 2 had decreased transcription. Transcription is the first step leading to gene expression.
"Further study may help us identify if these two distinct transcription patterns of inflammatory genes could possibly distinguish either two stages or two types of Alzheimer's disease," said study author Mathew Mizwicki, an assistant researcher at the David Geffen School of Medicine at UCLA.
While researchers found that 1alpha,25-dihydroxyvitamin D3 and resolvin D1 greatly improved the clearance of amyloid-beta by macrophages in patients in both groups, they discovered subtleties in the effects the two substances had on the expression of inflammatory genes in the two groups. In Group 1, the increased-inflammation group, macrophages showed a decrease of inflammatory activation; in Group 2, macrophages showed an increase of the inflammatory genes IL1 and TLRs when either 1alpha,25-Dihydroxyvitamin D3 or resolvin D1 were added.
More study is needed, Fiala said, but these differences could be associated with the severity of patients' nutritional and/or metabolic deficiencies of vitamin D3 and DHA, as well as the omega-3 fatty acid EPA (eicosapentaenoic acid).
"We may find that we need to carefully balance the supplementation with vitamin D3 and omega-3 fatty acids, depending on each patient in order to help promote efficient clearing of amyloid-beta," Fiala said. "This is a first step in understanding what form and in which patients these nutrition substances might work best."
According to Fiala, an active (not oxidized) form of omega-3 DHA, which is the precursor of the resolvin D1 used in this study, may work better than more commercially available forms of DHA, which generally are not protected against the oxidation that can render a molecule inactive.
Natural chemicals found in green tea and red wine may disrupt a key step of the Alzheimer's disease pathway, according to new research from the University of Leeds.
In early-stage laboratory experiments, the researchers identified the process which allows harmful clumps of protein to latch on to brain cells, causing them to die. They were able to interrupt this pathway using the purified extracts of EGCG from green tea and resveratrol from red wine.
The findings, published in the Journal of Biological Chemistry, offer potential new targets for developing drugs to treat Alzheimer's disease, which affects some 800,000 people in the UK alone, and for which there is currently no cure.
"This is an important step in increasing our understanding of the cause and progression of Alzheimer's disease," says lead researcher Professor Nigel Hooper of the University's Faculty of Biological Sciences. "It's a misconception that Alzheimer's is a natural part of aging; it's a disease that we believe can ultimately be cured through finding new opportunities for drug targets like this."
Alzheimer's disease is characterised by a distinct build-up of amyloid protein in the brain, which clumps together to form toxic, sticky balls of varying shapes. These amyloid balls latch on to the surface of nerve cells in the brain by attaching to proteins on the cell surface called prions, causing the nerve cells to malfunction and eventually die.
"We wanted to investigate whether the precise shape of the amyloid balls is essential for them to attach to the prion receptors, like the way a baseball fits snugly into its glove," says co-author Dr Jo Rushworth. "And if so, we wanted to see if we could prevent the amyloid balls binding to prion by altering their shape, as this would stop the cells from dying."
The team formed amyloid balls in a test tube and added them to human and animal brain cells. Professor Hooper said: "When we added the extracts from red wine and green tea, which recent research has shown to re-shape amyloid proteins, the amyloid balls no longer harmed the nerve cells. We saw that this was because their shape was distorted, so they could no longer bind to prion and disrupt cell function.
"We also showed, for the first time, that when amyloid balls stick to prion, it triggers the production of even more amyloid, in a deadly vicious cycle," he added.
Professor Hooper says that the team's next steps are to understand exactly how the amyloid-prion interaction kills off neurons.
"I'm certain that this will increase our understanding of Alzheimer's disease even further, with the potential to reveal yet more drug targets," he said.
Dr Simon Ridley, Head of Research at Alzheimer's Research UK, the UK's leading dementia research charity, which part-funded the study, said: "Understanding the causes of Alzheimer's is vital if we are to find a way of stopping the disease in its tracks. While these early-stage results should not be a signal for people to stock up on green tea and red wine, they could provide an important new lead in the search for new and effective treatments. With half a million people affected by Alzheimer's in the UK, we urgently need treatments that can halt the disease -- that means it's crucial to invest in research to take results like these from the lab bench to the clinic."
Eating Southern-style foods may be linked to a higher risk of stroke, according to research presented at the American Stroke Association's International Stroke Conference 2013.
In the first large-scale study on the relationship between Southern foods and stroke, researchers characterized a Southern diet by a high intake of foods such as fried chicken, fried fish, fried potatoes, bacon, ham, liver and gizzards, and sugary drinks such as sweet tea. In addition to being high in fat, fried foods tend to be heavily salted.
"We've got three major factors working together in the Southern-style diet to raise risks of cardiovascular disease: fatty foods are high in cholesterol, sugary drinks are linked to diabetes and salty foods lead to high blood pressure," said Suzanne Judd, Ph.D., M.P.H., lead researcher and a nutritional epidemiologist at the University of Alabama Birmingham's biostatistics department.
Previous research has shown that Southerners are about 20 percent more likely to have a stroke than the rest of Americans.
Comparing the dietary habits of more than 20,000 black and white adults, researchers found:
- Stroke frequency was directly proportional to how much Southern food participants ate.
- People who ate Southern foods about six times a week had a 41 percent higher stroke risk compared to those who ate it about once a month.
- Eating a Southern diet accounted for 63 percent of the higher risk of stroke among African-Americans above that of their white counterparts.
- Those whose diets were highest in fruits, vegetables, legumes and whole grains (eaten about five times a week) had a 29 percent lower stroke risk than those whose diets were the lowest in these foods (eaten about three times a week).
The study raises red flags for African-Americans who are five times more likely to eat Southern foods than whites, Judd said. And first-time stroke risk among blacks is almost double that of whites, according to American Stroke Association statistics.
Participants from 48 states answered telephone questionnaires about what foods they eat as part of the ongoing Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study (begun in 2003). Participants were evenly divided between men and women, and the minimum age was 45.
Each person underwent an in-person medical assessment including height, weight and blood pressure measurements; an electrocardiogram; and a blood test. Every six months after, participants answered follow-up telephone questions about their stroke incidence, sleep habits and overall health.
Researchers designed a mathematical model to group foods commonly eaten together into 56 different categories. Each person's eating habits were scored based on the categories. The scores were further analyzed in relation to how often they had a stroke.
About two-thirds of the participants who ate the most Southern-style foods lived in the southeastern United States. But, no matter where they live, people eating a lot of Southern foods should be more aware of their risks of stroke, Judd said.
Healthcare providers should educate patients about nutrition earlier, and ask patients about what they're eating, how much and how often, she said.
Men who consume high levels of vitamin C are at twice the risk of kidney stones than men who do not.
In the current study, published in JAMA Internal Medicine, the investigators followed over 23,000 Swedish men who were between 45 and 79 years old in 1997 up to the year 2009. None of them had kidney stones at baseline.
Close to 900 of the men took 1,000-milligram doses of vitamin C, and 3 percent of them (31 men) later had kidney stones. Less than 2 percent of those in the rest of the group developed kidney stones.
The researchers adjusted for factors which could undermine the reliability of the findings, such as education levels, ages, and body weights.
They revealed that those men who received the high-dose supplements had an elevated kidney stone risk ranging between 1.7 and 2.2 times.
The authors point out that there are no significantly proven reasons for any person to take such large amounts of vitamin C. The results of the study do not apply to vitamin C that comes from food.
Another outcome of the study was that multivitamin supplements that don't have large doses of vitamin C did not increase the risk of kidney stones.
The authors point out that more studies are needed to back up these findings, and they emphasize that people should not stop consuming vitamin C after reading this report. If you are concerned about your vitamin C intake or any health consequences related to vitamin supplementation, talk to your doctor.
Last year, a study presented at the Endocrine Society's 94th Annual Meeting in Houston, revealed that vitamin C and vitamin D supplements are associated with high calcium levels in the urine and blood,. High urine/blood calcium levels are linked to a higher risk of kidney stones.
Tuesday, February 5, 2013
Use of sunblock could lessen protective effects, suggest authors
[Exposure to ultraviolet-B and risk of developing rheumatoid arthritis among women in the Nurses' Health Study Online First doi 10.1136/annrheumdis-2012-202302]
Regular exposure to sunlight—specifically ultraviolet B (UVB)—may reduce the risk of developing rheumatoid arthritis, indicates a large long term study published online in the Annals of the Rheumatic Diseases.
But the effect of UVB exposure was only evident among older women, possibly because younger women are more aware of the hazards of sunlight and so cover up with sun block, suggest the authors.
They base their findings on participants in two phases of the US Nurses' Health Study (NHS), the first of which has tracked the health of more than 120,000 nurses since 1976, when they were aged between 30 and 55, until 2008.
The second (NHSII) has tracked the health of a further 115,500 nurses since 1989, when they were aged between 25 and 42, until 2009.
Rather than simply relying on geography to quantify likely levels of UVB exposure, the researchers used a more sensitive assessment, known as UV-B flux, which is a composite measure of UVB radiation, based on latitude, altitude, and cloud cover.
It is measured in R-B units: a count of 440 R-B units over 30 minutes, for example, is sufficient to produce slight redness in untanned white skin.
Exposure was then estimated according to the US state of residence, and ranged from an annual average of 93 in Alaska and Oregon to 196 in Hawaii and Arizona. Likely estimates of UV exposure at birth and by the age of 15 were also included.
Over the study period, 1314 women developed rheumatoid arthritis. Among nurses in the first NHS cohort, higher cumulative exposure to UVB was associated with a reduced risk of developing the disease.
Those with the highest levels of exposure were 21% less likely to develop rheumatoid arthritis than those with the least, the analysis showed.
This backs up the findings of other studies, showing a link between geography and the risk of rheumatoid arthritis as well as other autoimmune conditions, including type 1 diabetes, inflammatory bowel disease, and multiple sclerosis, say the authors.
But no such association for UV-B exposure was found among women in NHSII. These women were younger than those in the first NHS, and so might have been more savvy about the potential hazards of acquiring a tan, suggest the authors.
"Differences in sun protective behaviours (eg greater use of sun block in younger generations) may explain the disparate results," they explain.
They add that it is unclear at what stage of life the protective effect of UV-B occurs. Many of the study participants didn't move house between birth and their teens, and there was no difference in the results for these time points.
But they conclude: "Our study adds to the growing evidence that exposure to UV-B light is associated with decreased risk of rheumatoid arthritis. The mechanisms are not yet understood, but could be mediated by the cutaneous production of vitamin D and attenuated by use of sunscreen or sun avoidant behaviour."
A high intake of supplemental calcium appears to be associated with an increased risk of cardiovascular disease (CVD) death in men but not in women in a study of more 388,000 participants between the ages of 50 and 71 years, according to a report published Online First by JAMA Internal Medicine, a JAMA Network publication.
Calcium supplementation has become widely used, especially among the elderly population, because of its proposed bone health benefits. However, beyond calcium's established role in the prevention and treatment of osteoporosis, its health effect on nonskeletal outcomes, including cardiovascular health, remains largely unknown and has become "increasingly contentious," the authors write in the study background.
Qian Xiao, Ph.D., of the National Cancer Institute, Bethesda, Md., and colleagues examined whether the intake of dietary and supplemental calcium was associated with mortality from total CVD, heart disease and cerebrovascular diseases. The study participants were 388,229 men and women ages 50 to 71 years from the National Institutes of Health-AARP Diet and Health Study in six states and two metropolitan areas from 1995 through 1996.
"In this large, prospective study we found that supplemental but not dietary calcium intake was associated with an increased CVD mortality in men but not in women," the authors conclude.
During an average 12 years of follow-up, 7,904 CVD deaths in men and 3,874 CVD deaths in women were identified and supplements containing calcium were used by 51 percent of men and 70 percent of women. Compared with non-supplement users, men with an intake of supplemental calcium of more than 1,000 mg/day had an increased risk of total CVD death (risk ratio [RR], 1.20), more specifically with heart disease (RR, 1.19), but not significantly with cerebrovascular disease death (RR, 1.14).
For women, supplemental calcium intake was not associated with CVD death, heart disease death or cerebrovascular disease death. Dietary calcium intake also was not associated with CVD death in men or women.
"Whether there is a sex difference in the cardiovascular effect of calcium supplement warrants further investigation. Given the extensive use of calcium supplement in the population, it is of great importance to assess the effect of supplemental calcium use beyond bone health," the authors conclude.
20 hours of TV weekly may nearly halve sperm count; 15 or more hours of moderate to vigorous exercise weekly may boost sperm count
Men's sperm quality may be significantly affected by their levels of physical activity, according to a new study led by researchers at Harvard School of Public Health (HSPH). They found that healthy young men who were sedentary, as measured by hours of TV viewing, had lower sperm counts than those who were the most physically active.
"We know very little about how lifestyle may impact semen quality and male fertility in general so identifying two potentially modifiable factors that appear to have such a big impact on sperm counts is truly exciting," said lead author Audrey Gaskins, a doctoral student at HSPH.
The study will be published online February 4, 2013 in the British Journal of Sports Medicine.
Gaskins and her colleagues analyzed the semen quality of 189 men between the ages of 18 to 22 participating in the Rochester Young Men's Study during 2009 at the University of Rochester. The men were asked about their physical activity and TV-watching habits, in addition to health issues that may affect their sperm quality, such as diet, stress levels, and smoking.
Results showed that men who watched more than 20 hours of TV weekly had a 44% lower sperm count than those who watched almost no TV. Men who exercised for 15 or more hours weekly at a moderate to vigorous rate had a 73% higher sperm count than those who exercised less than 5 hours per week. Mild exercise did not affect sperm quality.
"The majority of the previous studies on physical activity and semen quality had focused on professional marathon runners and cyclists, who reach physical activity levels that most people in the world cannot match. We were able to examine a range of physical activity that is more relevant to men in the general population," said Jorge Chavarro, senior author of the study and assistant professor of nutrition and epidemiology at HSPH.
People tend to lose muscle mass as they age; researchers are investigating ways to delay or counteract age-related muscle loss. A study conducted by the Exercise Metabolism Research Group at McMaster University suggests that current guidelines for meat consumption are based on the protein needed to prevent deficiency without consideration for preservation of muscle mass, particularly for older individuals who are looking to maintain their muscle as they age. This research was published in the journal Applied Physiology, Nutrition, and Metabolism.
Thirty-five middle-aged men (~59 years old) participated in a study that found that eating a 6-ounce serving of 85% lean ground beef resulted in significant improvements in the rate of muscle protein synthesis following exercise. The investigators measured muscle protein synthesis (MPS), which is essential to the body’s ongoing growth, repair and maintenance of skeletal muscle in men who did and did not lift weights. What researchers determined was that the quantity of beef needed for optimal MPS for this age group is double the current recommended serving size of meat.
“Canada's Food Guide now suggests that consuming about 3oz (0.80 g/kg/d) of meat per serving is adequate to provide protein at the recommended level,” says Dr. Stuart Phillips, the study’s senior author and a researcher with the Exercise Metabolism Research Group at McMaster University. “However, our work shows that the quantity of beef needed to maximize the renewal of new muscle proteins was at least 6oz in middle-aged men. Our findings have clear ramifications for the current recommendations regarding protein to prevent muscle loss in aging.”
The article “Dose-dependent responses of myofibrillar protein synthesis with beef ingestion are enhanced with resistance exercise in middle-aged men” is available Open Access in the journal Applied Physiology, Nutrition, and Metabolism, DOI: 10.1139/apnm-2012-0092
"It is surprising that a serious disease such as type 1 diabetes could perhaps be prevented by a simple and safe intervention," said lead author Kassandra Munger, research associate in the Department of Nutrition at HSPH.
This study provides the strongest findings to date to suggest that vitamin D may be protective against type 1 diabetes.
In type 1 diabetes (once called juvenile-onset or insulin-dependent diabetes), the body's immune system attacks and permanently disables the insulin-making cells in the pancreas. About 5% of the estimated 25.8 million people in the United States with diabetes have type 1, according to the American Diabetes Association. Although it often starts in childhood, about 60% of type 1 diabetes cases occur after age 20.
Previous studies have suggested that a shortage of vitamin D might boost type 1 diabetes risk, although those studies mostly examined the link between vitamin D levels in pregnancy or childhood and the risk of type 1 diabetes in children. Other research, in young adults, uncovered an association between high vitamin D levels and a lowered risk of multiple sclerosis—an autoimmune disease genetically and epidemiologically related to type 1 diabetes—suggesting that inadequate vitamin D in adulthood may be an important risk factor for autoimmune diseases in general.
Long-term study of military personnel
The researchers conducted a prospective case-control study of U.S. military personnel on active duty, using blood samples from the Department of Defense Serum Repository, which contains more than 40 million samples collected from 8 million military personnel since the mid-1980s. Identifying 310 individuals diagnosed with type 1 diabetes between 1997 and 2009, the team examined blood samples taken before onset of the disease, and compared the samples with those of 613 people in a control group.
The researchers found that white, non-Hispanic, healthy young adults with higher serum levels (>75 nmol/L) of vitamin D had about half the risk of developing type 1 diabetes than those with the lowest levels of vitamin D (<75 nmol/L). Although the researchers found no significant association among Hispanics and blacks, the authors said this may be due to the small number of individuals in these groups.
"The risk of type 1 diabetes appears to be increased even at vitamin D levels that are commonly regarded as normal, suggesting that a substantial proportion of the population could benefit from increased vitamin D intake," said Alberto Ascherio, professor of epidemiology and nutrition at HSPH, the study's senior author.
About vitamin D
Worldwide, an estimated 1 billion people have inadequate levels of vitamin D in their blood, and deficiencies can be found in all ethnicities and age groups. While sun exposure is an excellent source of vitamin D, sunscreen, clothing, skin pigmentation, and winter months reduce vitamin D production. Food tends to be a poor source of vitamin D, with "good" sources, such as salmon and fortified milk, containing 400IU or less per serving. "Whereas it is premature to recommend universal use of vitamin D supplements for prevention of type 1 diabetes, the possibility that many cases could be prevented by supplementation with 1,000-4,000 IU/day, which is largely considered safe, is enticing," the authors said.
Alcohol + diet drinks may increase intoxication more than alcohol + regular drinks
A person's breath alcohol concentration (BrAC) after drinking is influenced by factors such as food.
New findings show that mixing alcohol with a diet soft drink can result in a higher BrAC than mixing alcohol with a regular or sugar-sweetened drink.
Individuals were unaware of these differences, which may pose safety risks such as drinking and driving.
An individual's breath alcohol concentration (BrAC) following alcohol intake is influenced by several factors, including food. While it is known that food delays the stomach emptying, thus reducing BrAC, only recently has the role of nonalcoholic drink mixers used with alcohol been explored as a factor influencing BrAC. A new comparison of BrACs of alcohol consumed with an artificial sweetener versus alcohol consumed with a sugared beverage has found that mixing alcohol with a diet soft drink can result in a higher BrAC.
Results will be published in the April 2013 issue of Alcoholism: Clinical & Experimental Research and are currently available at Early View.
"More attention needs to be paid to how alcohol is being consumed in the 'real world,'" said Cecile A. Marczinski, assistant professor of psychology at Northern Kentucky University. She referenced an earlier field study of bar patrons. "Researchers found that, one, individuals who reported consuming alcohol with diet beverages had the highest BrACs, as compared to all other bar patrons, and two, that women tended to be more frequent consumers of diet mixers with their alcohol. These good naturalistic observations give researchers many ideas to explore in a controlled laboratory setting."
Dennis L. Thombs, professor and chair of the department of behavioral and community health at UNT Health Science Center, was the author of the field study referenced by Marczinski. "Research on artificially sweetened drink mixers is new," he said. "I believe this might be only the third study published to date on this issue, and the findings are quite consistent with ours."
"I am really interested in drinking and driving as a problem, so I wanted to know if the simple choice of mixer could be the factor that puts a person above or below the legal limit," added Marczinski. "I also wanted to determine if any BrAC difference would be something that subjects would notice, since this has implications for safe drinking practices, including decisions to drive."
Study authors had 16 participants (8 females, 8 males) attend three sessions where they received one of three doses – 1.97 ml/kg vodka mixed with 3.94 ml/kg Squirt, 1.97 ml/kg vodka mixed with 3.94 ml/kg diet Squirt, and a placebo beverage – in random order. The participants' BrACs were recorded, as well as their self-reported ratings of subjective intoxication, fatigue, impairment, and willingness to drive. Their objective performance was assessed using a cued go/no-go reaction time task.
"Alcohol consumed with a diet mixer results in higher BrACs as compared to the same amount of alcohol consumed with a sugar-sweetened mixer," said Marczinski. "The subjects were unaware of this difference, as measured by various subjective ratings including feelings of intoxication, impairment, and willingness to drive. Moreover, their behavior was more impaired when subjects consumed the diet mixer."
When asked why mixing alcohol with a diet drink appears to elevate BrACs, Thombs explained that the stomach seems to treat sugar-sweetened beverages like food, which delays the stomach from emptying. "The best way to think about these effects is that sugar-sweetened alcohol mixers slow down the absorption of alcohol into bloodstream," he said. "Artificially sweetened alcohol mixers do not really elevate alcohol intoxication. Rather, the lack of sugar simply allows the rate of alcohol absorption to occur without hindrance."
Both Marczinski and Thombs were concerned about the risk that diet mixers can pose for alcohol-impaired driving. "In this study, subjects felt the same whether they drank the diet or regular mixed alcoholic beverage," said Marczinski. "However, they were above the limit of .08 when they consumed the diet mixer, and below it when they drank the regular mixed beverage. Choices to drink and drive, or engage in any other risky behavior, often depend on how people feel, rather than some objective measurement of impairment. Now alcohol researchers who are interested in prevention have something new to consider when developing or modifying intervention programs."
Thombs agreed. "Research on alcohol mixers is critically important for improving serving practices in on-premise drinking establishments," he said. "About one-half of all drinking and driving incidents are estimated to occur in persons leaving these settings. This type of research can provide guidance to policy-makers interested in improving the safety of bars and nightclubs."
"We have an obesity crisis in this country," added Marczinski. "As such, individuals tend to be conscious about how many calories they are consuming, and they might think that mixing alcohol with diet drinks is a healthy choice. Yet the average reader needs to know that while mixing alcohol with a diet beverage mixer may limit the amount of calories being consumed, higher BrACs are a much more significant health risk than a few extra calories."
"In natural drinking settings, such as bars and nightclubs, young women are significantly more likely than young men to order drinks mixed with diet cola," said Thombs. "I suspect this occurs because young women tend to be more weight conscious than young men. Thus, from a public health perspective, artificially sweetened alcohol mixers may place young women at greater risk for a range of problems associated with acute alcohol intoxication."