Scientists have provided new evidence that using more fish oil than vegetable oil in the diet decreases the formation of chemicals called prostanoids, which, when produced in excess, increase inflammation in various tissues and organs. The results, by William L. Smith, Professor and Chair of Biological Chemistry at the University of Michigan, Ann Arbor, and colleagues, may help in designing new anti-inflammatory drugs with fewer side effects than the ones currently available.
“Prostanoids help control blood pressure, fight allergies, and modulate inflammation, but too much of them – especially those made from vegetable oils – can also lead to increased pain, swelling, and redness in various tissues,” Smith says. “Our study shows that prostanoids made from fish oil are less effective at causing pain and swelling than those made from vegetable oil and that adding fish oil to the diet decreases the amount of prostanoids made from vegetable oil.”
The new study, to be published in the August 3 issue of the Journal of Biological Chemistry (http://www.jbc.org/), was selected as a “Paper of the Week” by the journal’s editors, meaning that it belongs to the top one percent of papers reviewed in significance and overall importance.
Smith and colleagues looked at the mutual effects of both oils by changing their respective amounts in cultured cells. As expected, a relative increase in fish oil lowered the amount of prostanoids from vegetable oil, although not always in the expected proportions.
Both fish and vegetable oils are converted into prostanoids through chemical reactions that are aided by enzymes called cyclo-oxygenases (COX), two types of which – COX-1 and COX-2 – are involved in the reactions. The scientists showed that, in reactions involving COX-1, when more fish oil is present, it preferentially binds to COX-1, thus limiting vegetable oil’s access to this enzyme. But in reactions involving COX-2, increasing the amount of fish oil did not change the way it binds to COX-2, so a significant portion of vegetable oil was still converted to prostanoids.
“This was completely unexpected,” Smith says. “This new result shows that COX-2 does not ‘prefer’ fish oil to vegetable oil. Regardless of the amount of extra fish oil that we added, COX-2 still helped convert all the vegetable oil available.”
This finding reveals for the first time a limit to how the body naturally regulates levels of prostanoids produced by fish and vegetable oil. If both oil types are present in the body, levels of prostanoids from fish oil will, in general, be higher than those coming from vegetable oil, but mechanisms such as the one involving COX-2 can counter this trend.
The researchers are now investigating why COX-1 and COX-2 act differently. One possibility is that since COX-2 has two binding sites, it can bind to both fish and vegetable oils. When fish oil binds to one of the two sites, it may prepare the other site to bind more easily to vegetable oil, a process called allostery.
Smith and his colleagues hope that by further investigating how prostanoids are regulated in the body, they can design potential drugs that bind to COX-2 and decrease levels of the vegetable oil prostanoids.
“The drugs that are currently used to inhibit COX-1 and COX-2 provide relief from the symptoms of inflammation and pain, but they still have many side effects,” Smith says. “By better understanding how prostanoids work at the cellular level, we hope to find new ways to regulate inflammation and create better anti-inflammatory drugs.”
Thursday, July 26, 2007
Tuesday, July 24, 2007
Eat fish -- especially if you drink lots of alcohol
Essential fatty acids (EFAs) are a necessary part of an individual's healthy diet.
New findings indicate that binge-drinking men have lower intakes of n-3 fats, one type of EFA.
This low intake exacerbates the already very low EFA levels.
Essential fatty acids (EFAs) are just that; an "essential" part of the total fat intake necessary for a healthy human diet. Most EFAs come from plants, but some are animal-sourced. A new study has found that men who binge drink have substandard intake of n-3 fats, one of two types of EFAs, indicating poor dietary choices with negative long-term health consequences.
Results are published in the August issue of Alcoholism: Clinical & Experimental Research.
"Essential fatty acids are important building blocks of living cells, making up a substantial part of cell walls," explained Norman Salem, Jr., chief of the Laboratory of Membrane Biochemistry & Biophysics at the National Institute on Alcohol Abuse and Alcoholism "EFAs also have many biological functions, and a lack of them leads to loss of growth and development, infertility, and a host of physiological and biochemical abnormalities." Salem is also the study's corresponding author.
The most important EFAs are polyunsaturated fatty acids (PUFA), said J. Thomas Brenna, professor of human nutrition and of chemistry & chemical biology at Cornell University. Particularly two types, Brenna noted: the omega-6 PUFA linoleic acid (LA), also called n-6 fats, and the omega-3 PUFA linolenic acid (ALA), also called n-3 fats. "Most Americans consume adequate amounts of LA in their diets through the use of vegetable oils, but tend to have low intakes of ALA," said Brenna.
This imbalance, added Salem, has become pronounced only in the last century and many believe it is a source of the increase of many common diseases in Western society. Salem and his co-authors wanted to investigate what influence alcohol consumption might have on EFA imbalance in the Western diet.
Researchers used data from 4,168 adults who self-reported their alcohol consumption as part of the 2001-2002 National Health and Nutrition Examination Survey. Participants were also interviewed about their EFA intake during a single previous 24-hour period.
Results indicate that EFA intake drops as alcohol consumption increases, particularly among men.
"Our most important finding is the decrease in n-3 EFA intake in binge-drinking men," said Salem. "We really couldn’t evaluate women who binge drink two or more times per week due to the low numbers in this population, although it is quite possible that we would obtain similar findings. The changes we found indicate that those who drink alcohol make food selections in such a way as to decrease foods with this important nutrient. The binge-drinking men have decreases in the longer chain n-3 fatty acids, the ones that we typically get from eating fish, and so this suggests that they eat less fish."
"Previous studies by Dr. Salem and colleagues have shown that requirements for these nutrients actually increase with greater alcohol consumption," noted Brenna. "Considering that the ALA levels are already low compared to the LA levels, these results are further reason for concern over the ALA intake of alcoholics."
"This helps to explain why alcohol abuse leads to losses in polyunsaturated fats in the circulation and organs," said Salem. "However, dietary influence does not explain all of the changes observed in past studies of fatty-acid changes in organs of alcohol abusers. Alcohol also has an effect on fatty acid metabolism, mainly through increasing fat break down."
Furthermore, said Brenna, alcohol has strong, lasting, and deleterious effects on the brain. "The brain depends on a supply of omega-3 PUFA," he said. The brains of men consuming high levels of alcohol, particularly those who regularly binge drink, are further compromised by a low intake of EFA."
"In summary," said Salem, "for those who drink, especially binge drinkers or those who drink more than one drink per day on average: make sure that you obtain your sources of n-3 fatty acids in the diet, that is, eat more fish."
New findings indicate that binge-drinking men have lower intakes of n-3 fats, one type of EFA.
This low intake exacerbates the already very low EFA levels.
Essential fatty acids (EFAs) are just that; an "essential" part of the total fat intake necessary for a healthy human diet. Most EFAs come from plants, but some are animal-sourced. A new study has found that men who binge drink have substandard intake of n-3 fats, one of two types of EFAs, indicating poor dietary choices with negative long-term health consequences.
Results are published in the August issue of Alcoholism: Clinical & Experimental Research.
"Essential fatty acids are important building blocks of living cells, making up a substantial part of cell walls," explained Norman Salem, Jr., chief of the Laboratory of Membrane Biochemistry & Biophysics at the National Institute on Alcohol Abuse and Alcoholism "EFAs also have many biological functions, and a lack of them leads to loss of growth and development, infertility, and a host of physiological and biochemical abnormalities." Salem is also the study's corresponding author.
The most important EFAs are polyunsaturated fatty acids (PUFA), said J. Thomas Brenna, professor of human nutrition and of chemistry & chemical biology at Cornell University. Particularly two types, Brenna noted: the omega-6 PUFA linoleic acid (LA), also called n-6 fats, and the omega-3 PUFA linolenic acid (ALA), also called n-3 fats. "Most Americans consume adequate amounts of LA in their diets through the use of vegetable oils, but tend to have low intakes of ALA," said Brenna.
This imbalance, added Salem, has become pronounced only in the last century and many believe it is a source of the increase of many common diseases in Western society. Salem and his co-authors wanted to investigate what influence alcohol consumption might have on EFA imbalance in the Western diet.
Researchers used data from 4,168 adults who self-reported their alcohol consumption as part of the 2001-2002 National Health and Nutrition Examination Survey. Participants were also interviewed about their EFA intake during a single previous 24-hour period.
Results indicate that EFA intake drops as alcohol consumption increases, particularly among men.
"Our most important finding is the decrease in n-3 EFA intake in binge-drinking men," said Salem. "We really couldn’t evaluate women who binge drink two or more times per week due to the low numbers in this population, although it is quite possible that we would obtain similar findings. The changes we found indicate that those who drink alcohol make food selections in such a way as to decrease foods with this important nutrient. The binge-drinking men have decreases in the longer chain n-3 fatty acids, the ones that we typically get from eating fish, and so this suggests that they eat less fish."
"Previous studies by Dr. Salem and colleagues have shown that requirements for these nutrients actually increase with greater alcohol consumption," noted Brenna. "Considering that the ALA levels are already low compared to the LA levels, these results are further reason for concern over the ALA intake of alcoholics."
"This helps to explain why alcohol abuse leads to losses in polyunsaturated fats in the circulation and organs," said Salem. "However, dietary influence does not explain all of the changes observed in past studies of fatty-acid changes in organs of alcohol abusers. Alcohol also has an effect on fatty acid metabolism, mainly through increasing fat break down."
Furthermore, said Brenna, alcohol has strong, lasting, and deleterious effects on the brain. "The brain depends on a supply of omega-3 PUFA," he said. The brains of men consuming high levels of alcohol, particularly those who regularly binge drink, are further compromised by a low intake of EFA."
"In summary," said Salem, "for those who drink, especially binge drinkers or those who drink more than one drink per day on average: make sure that you obtain your sources of n-3 fatty acids in the diet, that is, eat more fish."
Monday, July 23, 2007
Childhood sun exposure may lower risk of MS
People who spent more time in the sun as children may have a lower risk of developing multiple sclerosis (MS) than people who had less sun exposure during childhood, according to a study published in the July 24, 2007, issue of Neurology®, the medical journal of the American Academy of Neurology.
For the study, researchers surveyed 79 pairs of identical twins with the same genetic risk for MS in which only one twin had MS. The twins were asked to specify whether they or their twin spent more time outdoors during hot days, cold days, and summer, and which one spent more time sun tanning, going to the beach and playing team sports as a child.
The study found the twin with MS spent less time in the sun as a child than the twin who did not have MS. Depending on the activity, the twin who spent more hours outdoors had a 25 to 57 percent reduced risk of developing MS. For example, the risk of developing MS was 49 percent lower for twins who spent more time sun tanning than their siblings.
“Sun exposure appears to have a protective effect against MS,” said study authors Talat Islam, MBBS, PhD, and Thomas Mack, MD, MPH, with the Keck School of Medicine of the University of Southern California in Los Angeles. “Exposure to ultra violet rays may induce protection against MS by alternative mechanisms, either directly by altering the cellular immune response or indirectly by producing immunoactive vitamin D.”
The study also found the protective effect of sun exposure was seen only among female twin pairs, but Mack says this novel finding must be viewed with caution since only a few male twins were involved in the study.
“Our findings note the importance of sun exposure among people with identical genetic risk for MS,” said Mack. “High priority should be given to research into how sun exposure reduces MS risk if we are to unravel the mystery of what causes MS.”
For the study, researchers surveyed 79 pairs of identical twins with the same genetic risk for MS in which only one twin had MS. The twins were asked to specify whether they or their twin spent more time outdoors during hot days, cold days, and summer, and which one spent more time sun tanning, going to the beach and playing team sports as a child.
The study found the twin with MS spent less time in the sun as a child than the twin who did not have MS. Depending on the activity, the twin who spent more hours outdoors had a 25 to 57 percent reduced risk of developing MS. For example, the risk of developing MS was 49 percent lower for twins who spent more time sun tanning than their siblings.
“Sun exposure appears to have a protective effect against MS,” said study authors Talat Islam, MBBS, PhD, and Thomas Mack, MD, MPH, with the Keck School of Medicine of the University of Southern California in Los Angeles. “Exposure to ultra violet rays may induce protection against MS by alternative mechanisms, either directly by altering the cellular immune response or indirectly by producing immunoactive vitamin D.”
The study also found the protective effect of sun exposure was seen only among female twin pairs, but Mack says this novel finding must be viewed with caution since only a few male twins were involved in the study.
“Our findings note the importance of sun exposure among people with identical genetic risk for MS,” said Mack. “High priority should be given to research into how sun exposure reduces MS risk if we are to unravel the mystery of what causes MS.”
Association between low cholesterol levels and cancer
Study finds association between low cholesterol levels and cancer
Benefits of statin therapy outweigh potential small risk
Millions of Americans take statins to lower their cholesterol, but how low should you go" Many scientific studies support the benefits of lowering low-density lipoprotein (LDL) cholesterol, and achieving low LDL cholesterol levels is one of the most important steps in preventing heart disease. New research, however, provides evidence for an association between low LDL levels and cancer risk.
The authors of the study, published in the July 31, 2007, issue of the Journal of the American College of Cardiology (JACC), set out to understand how and why statins cause side effects, particularly damage to the liver and muscle cells. The study findings support taking multiple medications rather than high-dose statins to minimize those side effects. The researchers did not expect to find the increased cancer risk (one additional incident per 1,000 patients) from low LDL levels, and additional studies have already begun to investigate this potential risk further. A key component in future studies will be to confirm the risk and to identify whether the risk may be a side effect of statins or just low LDL.
“This analysis doesn’t implicate the statin in increasing the risk of cancer,” said lead author Richard H. Karas, M.D., F.A.C.C., professor of medicine at Tufts University School of Medicine. “The demonstrated benefits of statins in lowering the risk of heart disease remain clear; however, certain aspects of lowering LDL with statins remain controversial and merit further research.”
The researchers found one additional incident of cancer per 1,000 patients with low LDL levels when compared to patients with higher LDL levels. In their evaluation of randomized controlled statin trials published before November 2005, the researchers looked at 13 treatment arms consisting of 41,173 patients.
Researchers assessed absolute change and percentage of change in LDL reduction and the resulting achieved LDL levels in relation to rates of newly diagnosed cancer in each treatment arm. They also looked at the relationship between low, intermediate and high doses of statins and rates of newly diagnosed cancer. Although they did not find a relationship between percent of change and absolute change in LDL levels, they observed higher rates of newly diagnosed cancer among patients with lower achieved LDL levels. In addition, the new cancers were not of any specific type or location.
Recent data from large-scale statin trials have shown that more intensive LDL lowering can provide significant cardiovascular benefits to higher-risk patients. In response to these findings, recent national guidelines have advocated for lower LDL goals and higher doses of statins to reach them. However, informal observations linking intensive LDL lowering and higher incidence of reported health problems, including liver and muscle toxicity and cancer, has introduced some concern over the safety of such treatments.
These concerns in part prompted the current study. However, the current findings are not definitive, as limitations of the study show. Researchers performed their analysis from summary data taken directly from published manuscripts of each trial. An analysis based on data for each individual patient would have yielded more specific and potentially more compelling results, said Dr. Karas.
“These current findings provide insufficient evidence that there is any problem with LDL lowering that outweighs its significant benefits on vascular disease,” said John C. La Rosa, M.D., who wrote an accompanying editorial in the July 31 issue of JACC. However, “we must continue to be vigilant in ensuring that its benefit clearly outweighs its risk.”
Although the cancer risk was surprising, the researchers primarily sought to determine how and why statins cause side effects, particularly damage to the liver and muscle cells. For this portion of the study, researchers analyzed 23 statin treatment arms that included 75,317 patients with a combined 309,506 years of follow up. A link between LDL lowering and liver or muscle irritation was not found. However, liver toxicity levels increased with higher statin dosage. Based on their findings, the researchers concluded that moderate-dose therapy with multiple medications including statins may prove to be preferable to high-dose therapy with statins alone. Dr. Karas emphasized that patients are advised to continue their statin treatments and, as always, consult their doctor before discontinuing use of any medication.
“While these results raise important new questions about statin use, they do not demonstrate a causal relationship between statins and cancer,” said James Dove, M.D., F.A.C.C., president of the American College of Cardiology. “This study is hypothesis-generating, not hypothesis-proving.”
Benefits of statin therapy outweigh potential small risk
Millions of Americans take statins to lower their cholesterol, but how low should you go" Many scientific studies support the benefits of lowering low-density lipoprotein (LDL) cholesterol, and achieving low LDL cholesterol levels is one of the most important steps in preventing heart disease. New research, however, provides evidence for an association between low LDL levels and cancer risk.
The authors of the study, published in the July 31, 2007, issue of the Journal of the American College of Cardiology (JACC), set out to understand how and why statins cause side effects, particularly damage to the liver and muscle cells. The study findings support taking multiple medications rather than high-dose statins to minimize those side effects. The researchers did not expect to find the increased cancer risk (one additional incident per 1,000 patients) from low LDL levels, and additional studies have already begun to investigate this potential risk further. A key component in future studies will be to confirm the risk and to identify whether the risk may be a side effect of statins or just low LDL.
“This analysis doesn’t implicate the statin in increasing the risk of cancer,” said lead author Richard H. Karas, M.D., F.A.C.C., professor of medicine at Tufts University School of Medicine. “The demonstrated benefits of statins in lowering the risk of heart disease remain clear; however, certain aspects of lowering LDL with statins remain controversial and merit further research.”
The researchers found one additional incident of cancer per 1,000 patients with low LDL levels when compared to patients with higher LDL levels. In their evaluation of randomized controlled statin trials published before November 2005, the researchers looked at 13 treatment arms consisting of 41,173 patients.
Researchers assessed absolute change and percentage of change in LDL reduction and the resulting achieved LDL levels in relation to rates of newly diagnosed cancer in each treatment arm. They also looked at the relationship between low, intermediate and high doses of statins and rates of newly diagnosed cancer. Although they did not find a relationship between percent of change and absolute change in LDL levels, they observed higher rates of newly diagnosed cancer among patients with lower achieved LDL levels. In addition, the new cancers were not of any specific type or location.
Recent data from large-scale statin trials have shown that more intensive LDL lowering can provide significant cardiovascular benefits to higher-risk patients. In response to these findings, recent national guidelines have advocated for lower LDL goals and higher doses of statins to reach them. However, informal observations linking intensive LDL lowering and higher incidence of reported health problems, including liver and muscle toxicity and cancer, has introduced some concern over the safety of such treatments.
These concerns in part prompted the current study. However, the current findings are not definitive, as limitations of the study show. Researchers performed their analysis from summary data taken directly from published manuscripts of each trial. An analysis based on data for each individual patient would have yielded more specific and potentially more compelling results, said Dr. Karas.
“These current findings provide insufficient evidence that there is any problem with LDL lowering that outweighs its significant benefits on vascular disease,” said John C. La Rosa, M.D., who wrote an accompanying editorial in the July 31 issue of JACC. However, “we must continue to be vigilant in ensuring that its benefit clearly outweighs its risk.”
Although the cancer risk was surprising, the researchers primarily sought to determine how and why statins cause side effects, particularly damage to the liver and muscle cells. For this portion of the study, researchers analyzed 23 statin treatment arms that included 75,317 patients with a combined 309,506 years of follow up. A link between LDL lowering and liver or muscle irritation was not found. However, liver toxicity levels increased with higher statin dosage. Based on their findings, the researchers concluded that moderate-dose therapy with multiple medications including statins may prove to be preferable to high-dose therapy with statins alone. Dr. Karas emphasized that patients are advised to continue their statin treatments and, as always, consult their doctor before discontinuing use of any medication.
“While these results raise important new questions about statin use, they do not demonstrate a causal relationship between statins and cancer,” said James Dove, M.D., F.A.C.C., president of the American College of Cardiology. “This study is hypothesis-generating, not hypothesis-proving.”
NSAIDs treatment can reduce colorectal cancer risk
Study confirms that NSAIDs treatment can reduce colorectal cancer risk
Safer drugs needed before regular preventive therapy can be recommended
A study of Medicare patients with osteoarthritis provides additional evidence that non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin reduce the risk of colorectal cancer. Earlier investigations of the drugs’ impact on tumor development could not rule out the possibility that an observed protective effect was caused by other preventive health care measures. The current study, led by a Massachusetts General Hospital (MGH) physician, appears in the August 2007 Journal of General Internal Medicine.
“This is good news for people who take NSAIDs regularly for osteoarthritis,” says Elizabeth Lamont, MD, MS, of the MGH Cancer Center, the study’s lead author. “Although patients face risks such as bleeding or kidney damage from this therapy, they probably are at a lower risk of developing colorectal cancer.” Because of the risks posed by the dosage used to treat osteoarthritis, she and her co-authors stress that currently available NSAIDs should not be used solely to prevent cancer.
Earlier randomized trials clearly showed that NSAID treatment can prevent the development of precancerous colorectal polyps, but whether or not such therapy also reduces the risk of invasive colorectal cancer has not yet been confirmed. Those trials used relatively low doses of aspirin and showed no significant differences in colorectal cancer rates between the aspirin and placebo groups. While many observational studies have shown a protective effect of NSAIDs against colorectal cancer, interpretation of some of those results may have been clouded by other healthy behaviors of the participants.
“It would be ideal to conduct a randomized clinical trial – in which half the patients receive NSAIDs at doses higher than those used in prior trials and half receive placebos – and follow both groups for many years for evidence of cancer. But such trials are expensive, time consuming, and could present real health risks to participants. Therefore, we took advantage of a natural ‘experiment’ by comparing data from patients known to regularly take higher amounts of NSAIDs with that from those taking lower doses in order to evaluate any effect on colorectal cancer risk.”
First the researchers reviewed data from the 1993-94 National Ambulatory Medical Care Survey, in which physicians report on the diagnoses of and treatments prescribed to patients seen during a randomly selected week. Those results verified that older patients with osteoarthritis were more than four times as likely to take NSAIDs as were those without osteoarthritis. They then analyzed information from the Survival Epidemiology and End-Results (SEER)-Medicare program, studying groups of elderly Medicare patients with and without colorectal cancer, to search for associations with NSAID use.
Comparing information on 4,600 individuals with colorectal cancer to data from 100,000 controls, they found that a history of osteoarthritis was associated with a 15 percent reduction in the likelihood of a colorectal cancer diagnosis. A similar association was seen when total knee replacement was used as a marker for NSAID treatment.
“The magnitude of colorectal cancer risk reduction between patients with and without osteoarthritis is completely consistent with the risk reduction for pre-cancerous polyps reported in clinical trials of NSAIDs,” Lamont says. “Confirming this association supports the need for further research to identify NSAID agents safe enough to be used for regular, preventive therapy by the general population.”
Safer drugs needed before regular preventive therapy can be recommended
A study of Medicare patients with osteoarthritis provides additional evidence that non-steroidal anti-inflammatory drugs (NSAIDs) such as aspirin reduce the risk of colorectal cancer. Earlier investigations of the drugs’ impact on tumor development could not rule out the possibility that an observed protective effect was caused by other preventive health care measures. The current study, led by a Massachusetts General Hospital (MGH) physician, appears in the August 2007 Journal of General Internal Medicine.
“This is good news for people who take NSAIDs regularly for osteoarthritis,” says Elizabeth Lamont, MD, MS, of the MGH Cancer Center, the study’s lead author. “Although patients face risks such as bleeding or kidney damage from this therapy, they probably are at a lower risk of developing colorectal cancer.” Because of the risks posed by the dosage used to treat osteoarthritis, she and her co-authors stress that currently available NSAIDs should not be used solely to prevent cancer.
Earlier randomized trials clearly showed that NSAID treatment can prevent the development of precancerous colorectal polyps, but whether or not such therapy also reduces the risk of invasive colorectal cancer has not yet been confirmed. Those trials used relatively low doses of aspirin and showed no significant differences in colorectal cancer rates between the aspirin and placebo groups. While many observational studies have shown a protective effect of NSAIDs against colorectal cancer, interpretation of some of those results may have been clouded by other healthy behaviors of the participants.
“It would be ideal to conduct a randomized clinical trial – in which half the patients receive NSAIDs at doses higher than those used in prior trials and half receive placebos – and follow both groups for many years for evidence of cancer. But such trials are expensive, time consuming, and could present real health risks to participants. Therefore, we took advantage of a natural ‘experiment’ by comparing data from patients known to regularly take higher amounts of NSAIDs with that from those taking lower doses in order to evaluate any effect on colorectal cancer risk.”
First the researchers reviewed data from the 1993-94 National Ambulatory Medical Care Survey, in which physicians report on the diagnoses of and treatments prescribed to patients seen during a randomly selected week. Those results verified that older patients with osteoarthritis were more than four times as likely to take NSAIDs as were those without osteoarthritis. They then analyzed information from the Survival Epidemiology and End-Results (SEER)-Medicare program, studying groups of elderly Medicare patients with and without colorectal cancer, to search for associations with NSAID use.
Comparing information on 4,600 individuals with colorectal cancer to data from 100,000 controls, they found that a history of osteoarthritis was associated with a 15 percent reduction in the likelihood of a colorectal cancer diagnosis. A similar association was seen when total knee replacement was used as a marker for NSAID treatment.
“The magnitude of colorectal cancer risk reduction between patients with and without osteoarthritis is completely consistent with the risk reduction for pre-cancerous polyps reported in clinical trials of NSAIDs,” Lamont says. “Confirming this association supports the need for further research to identify NSAID agents safe enough to be used for regular, preventive therapy by the general population.”
Saturday, July 21, 2007
Prostate drug doesn't limit sex in most men
Finasteride, found earlier to reduce prostate cancer incidence by nearly 25 percent, has slight impact that lessens over time
Men and their physicians need not hesitate to use a drug proven effective in preventing prostate cancer out of concern that it is likely to cause sexual dysfunction, say authors of a study conducted by the Southwest Oncology Group.
The authors, who surveyed more than 17,000 men 55 and older for seven years, reported their results in the July 4 Journal of the National Cancer Institute. The study found that men given finasteride reported on average more dysfunction than did men given a placebo. That small effect diminished over the seven years.
The results allay concerns about a negative side effect associated with finasteride up till now. Physicians usually warn that sexual dysfunction is a possibility when they discuss the drug with patients. Finasteride is an FDA-approved drug for the treatment of benign prostatic hyperplasia, but it is not yet FDA-approved for the prevention or reduction in risk for prostate cancer.
The study’s large sample and long follow-up period allowed researchers to examine whether or not finasteride negatively affected sexual function and, if so, whether this effect was lasting, said Carol Moinpour, Ph.D., of the Fred Hutchison Cancer Research Center in Seattle, the study’s lead author. She coordinates quality-of-life studies for the Southwest Oncology Group, the nation’s largest National Cancer Institute-funded clinical trials network.
The study grew out of the Prostate Cancer Prevention Trial, a large double-blind National Cancer Institute-funded study which found that finasteride, a drug which curbs the proliferation of prostate gland cells, is effective at preventing prostate cancer in men age 55 and older. The 2003 results of that trial, conducted by the Southwest Oncology Group in more than 18,000 men, showed that finasteride could reduce a man’s chances of getting prostate cancer by almost 25 percent.
The authors of the newly published sexual function results wanted to assess how many men in the Prostate Cancer Prevention Trial reported experiencing sexual dysfunction, and whether the problems decreased or increased over time. In earlier studies, some men taking finasteride reported decreased libido, impotence and other signs of diminished sexual function. But these studies were short-term and didn’t try to assess the effects of age and other health factors, as well as individual variation.
The study authors used two surveys, a widely used Sexual Problems Scale and another questionnaire which they created, the Sexual Activity Scale. They also gathered other data to take into account other health factors that affect sexual function, such as age, medical conditions and smoking status. They surveyed the subjects three times in the first year and then annually for seven years.
“Was this average decrease (in sexual function) an important difference" We concluded it was not,” Moinpour said, adding that there were much larger differences due simply to individual variation among men in the trial.
The study suggests that finasteride will cause little or no sexual dysfunction for most men who decide to take it, conclude the authors.
Men and their physicians need not hesitate to use a drug proven effective in preventing prostate cancer out of concern that it is likely to cause sexual dysfunction, say authors of a study conducted by the Southwest Oncology Group.
The authors, who surveyed more than 17,000 men 55 and older for seven years, reported their results in the July 4 Journal of the National Cancer Institute. The study found that men given finasteride reported on average more dysfunction than did men given a placebo. That small effect diminished over the seven years.
The results allay concerns about a negative side effect associated with finasteride up till now. Physicians usually warn that sexual dysfunction is a possibility when they discuss the drug with patients. Finasteride is an FDA-approved drug for the treatment of benign prostatic hyperplasia, but it is not yet FDA-approved for the prevention or reduction in risk for prostate cancer.
The study’s large sample and long follow-up period allowed researchers to examine whether or not finasteride negatively affected sexual function and, if so, whether this effect was lasting, said Carol Moinpour, Ph.D., of the Fred Hutchison Cancer Research Center in Seattle, the study’s lead author. She coordinates quality-of-life studies for the Southwest Oncology Group, the nation’s largest National Cancer Institute-funded clinical trials network.
The study grew out of the Prostate Cancer Prevention Trial, a large double-blind National Cancer Institute-funded study which found that finasteride, a drug which curbs the proliferation of prostate gland cells, is effective at preventing prostate cancer in men age 55 and older. The 2003 results of that trial, conducted by the Southwest Oncology Group in more than 18,000 men, showed that finasteride could reduce a man’s chances of getting prostate cancer by almost 25 percent.
The authors of the newly published sexual function results wanted to assess how many men in the Prostate Cancer Prevention Trial reported experiencing sexual dysfunction, and whether the problems decreased or increased over time. In earlier studies, some men taking finasteride reported decreased libido, impotence and other signs of diminished sexual function. But these studies were short-term and didn’t try to assess the effects of age and other health factors, as well as individual variation.
The study authors used two surveys, a widely used Sexual Problems Scale and another questionnaire which they created, the Sexual Activity Scale. They also gathered other data to take into account other health factors that affect sexual function, such as age, medical conditions and smoking status. They surveyed the subjects three times in the first year and then annually for seven years.
“Was this average decrease (in sexual function) an important difference" We concluded it was not,” Moinpour said, adding that there were much larger differences due simply to individual variation among men in the trial.
The study suggests that finasteride will cause little or no sexual dysfunction for most men who decide to take it, conclude the authors.
Wednesday, July 11, 2007
Poor diets = more respiratory symptoms in teens
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.”
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.”
Selenium = increased risk for diabetes
A new analysis of data from a large national study found that people who took a 200 microgram selenium supplement each day for almost eight years had an increased risk of developing type 2 diabetes than those who took a placebo or dummy pill.
The data came from the Nutritional Prevention of Cancer Trial (NPC), a large randomized, multi-center, clinical trial from the eastern United States, designed to evaluate whether selenium supplements prevent skin cancer. In the study being published, researchers selected 1,202 participants who did not have diabetes when they were enrolled in the NPC Trial. Half received a 200 microgram selenium supplement and half received a placebo pill for an average of 7.7 years.
Saverio Stranges, MD, PhD, lead author of the study, says that the findings from this study suggest that selenium supplements do not prevent diabetes and that they might be harmful. “At this time, the evidence that people should take selenium supplements is extremely limited. We have observed an increased risk for diabetes over the long term in the group of participants who took selenium supplements.”
Dr. Stranges is currently working at Warwick Medical School, UK, but previously worked at the State University of New York at Buffalo. Other authors of the article include Mary E. Reid, PhD, and James R. Marshall, PhD, researchers at the Roswell Park Cancer Institute in Buffalo.
Selenium is a naturally occurring trace mineral present in soil and foods. The body need selenium in minute amounts to aid in metabolism. Selenium supplements are widely promoted on the Internet for conditions ranging from cold sores and shingles to arthritis and multiple sclerosis. They are sold to prevent aging, enhance fertility, prevent cancer and get rid of toxic minerals such as mercury, lead and cadmium.
Selenium supplements have shown some promise in preventing prostate cancer. Because of selenium’s antioxidant activities, some scientists feel it might be effective against diabetes.
In the current study, 58 out of 600 participants in the selenium group and 39 out of 602 participants in the placebo group developed type 2 diabetes. After 7.7 years of follow-up, the relative risk rate was approximately 50 percent higher among those randomly selected for the selenium group than among those randomly placed in the placebo group.
The results consistently showed higher risks of disease among participants receiving selenium across subgroups of baseline age, gender, and smoking status. However, the selenium supplements had no impact on the most overweight participants. The risk of developing diabetes tended to be higher in people who had higher blood selenium levels at the start of the study.
Dr. Stranges said, “No single study can provide the answer to a scientific question, but at this time, selenium supplementation does not appear to prevent type 2 diabetes, and it may increase risk of the disease. However, our understanding of the mechanisms whereby selenium would increase risk of diabetes is very limited at this time and this issue needs to be further explored. Nevertheless, I would not advise patients to take selenium supplements greater than those in multiple vitamins.”
About 60 percent of Americans take multivitamin pills, many of which contain between 33 and 200 micrograms of selenium, in addition to the selenium taken in from food and the air. The RDA (recommended dietary allowance) for selenium varies by age. For people aged 14 and over, 55 micrograms per day is recommended for the body to function normally.
Dr. Stranges said that selenium levels in soil in United States are higher than the minimum needed to optimize metabolism, so people in the United States should not need to take selenium supplements greater than those in multivitamin supplements.
In an accompanying editorial, Eliseo Guallar, MD, DrPH, from Johns Hopkins University Bloomberg School of Public Health, says the article is “more bad news for supplements.” He says that the NPC trial is the largest and longest experimental study available comparing selenium supplements to placebo, that selenium has a narrow therapeutic range and that at high levels, it can be toxic.
“What the U.S. public needs to know,” Dr. Guallar says, “is that most people in the United States have adequate selenium in their diet. Moreover, taking selenium supplements on top of an adequate dietary intake may cause diabetes.”
The data came from the Nutritional Prevention of Cancer Trial (NPC), a large randomized, multi-center, clinical trial from the eastern United States, designed to evaluate whether selenium supplements prevent skin cancer. In the study being published, researchers selected 1,202 participants who did not have diabetes when they were enrolled in the NPC Trial. Half received a 200 microgram selenium supplement and half received a placebo pill for an average of 7.7 years.
Saverio Stranges, MD, PhD, lead author of the study, says that the findings from this study suggest that selenium supplements do not prevent diabetes and that they might be harmful. “At this time, the evidence that people should take selenium supplements is extremely limited. We have observed an increased risk for diabetes over the long term in the group of participants who took selenium supplements.”
Dr. Stranges is currently working at Warwick Medical School, UK, but previously worked at the State University of New York at Buffalo. Other authors of the article include Mary E. Reid, PhD, and James R. Marshall, PhD, researchers at the Roswell Park Cancer Institute in Buffalo.
Selenium is a naturally occurring trace mineral present in soil and foods. The body need selenium in minute amounts to aid in metabolism. Selenium supplements are widely promoted on the Internet for conditions ranging from cold sores and shingles to arthritis and multiple sclerosis. They are sold to prevent aging, enhance fertility, prevent cancer and get rid of toxic minerals such as mercury, lead and cadmium.
Selenium supplements have shown some promise in preventing prostate cancer. Because of selenium’s antioxidant activities, some scientists feel it might be effective against diabetes.
In the current study, 58 out of 600 participants in the selenium group and 39 out of 602 participants in the placebo group developed type 2 diabetes. After 7.7 years of follow-up, the relative risk rate was approximately 50 percent higher among those randomly selected for the selenium group than among those randomly placed in the placebo group.
The results consistently showed higher risks of disease among participants receiving selenium across subgroups of baseline age, gender, and smoking status. However, the selenium supplements had no impact on the most overweight participants. The risk of developing diabetes tended to be higher in people who had higher blood selenium levels at the start of the study.
Dr. Stranges said, “No single study can provide the answer to a scientific question, but at this time, selenium supplementation does not appear to prevent type 2 diabetes, and it may increase risk of the disease. However, our understanding of the mechanisms whereby selenium would increase risk of diabetes is very limited at this time and this issue needs to be further explored. Nevertheless, I would not advise patients to take selenium supplements greater than those in multiple vitamins.”
About 60 percent of Americans take multivitamin pills, many of which contain between 33 and 200 micrograms of selenium, in addition to the selenium taken in from food and the air. The RDA (recommended dietary allowance) for selenium varies by age. For people aged 14 and over, 55 micrograms per day is recommended for the body to function normally.
Dr. Stranges said that selenium levels in soil in United States are higher than the minimum needed to optimize metabolism, so people in the United States should not need to take selenium supplements greater than those in multivitamin supplements.
In an accompanying editorial, Eliseo Guallar, MD, DrPH, from Johns Hopkins University Bloomberg School of Public Health, says the article is “more bad news for supplements.” He says that the NPC trial is the largest and longest experimental study available comparing selenium supplements to placebo, that selenium has a narrow therapeutic range and that at high levels, it can be toxic.
“What the U.S. public needs to know,” Dr. Guallar says, “is that most people in the United States have adequate selenium in their diet. Moreover, taking selenium supplements on top of an adequate dietary intake may cause diabetes.”
Low vitamin D levels common in children
Low vitamin D levels may be common in otherwise healthy children
Many otherwise healthy children and adolescents have low vitamin D levels, which may put them at risk for bone diseases such as rickets. African American children, children above age nine and with low dietary vitamin D intake were the most likely to have low levels of vitamin D in their blood, according to researchers from The Children’s Hospital of Philadelphia.
A study in the current issue of the American Journal of Clinical Nutrition measured blood levels of vitamin D in 382 healthy children between six years and 21 years of age living in the northeastern U.S. Researchers assessed dietary and supplemental vitamin D intake, as well as body mass, and found that more than half of the children had low blood levels of vitamin D. Of the subjects, 55 percent of the children had inadequate vitamin D blood levels and 68 percent overall had low blood levels of the vitamin in the wintertime.
“The best indicator of a person’s vitamin D status is the blood level of a vitamin D compound called 25-hydroxyvitamin D,” said Babette Zemel, Ph.D., a nutritional anthropologist at Children’s Hospital and primary investigator of this study. “Vitamin D deficiency remains an under-recognized problem overall, and is not well studied in children.”
Vitamin D is crucial for musculoskeletal health. The primary dietary source of the vitamin is fortified milk, but the best way to increase vitamin D levels is from exposure to sunshine. Severe deficits in vitamin D may lead to muscle weakness, defective bone mineralization and rickets. In addition to musculoskeletal effects, vitamin D is important for immune function, and low blood levels of the vitamin may contribute to diseases such as hypertension, cancer, multiple sclerosis and type 1 diabetes. Decreased blood levels of vitamin D have also been linked to obesity.
Further study is needed to determine the appropriate blood levels of vitamin D in children, said Dr. Zemel, who added that a review of the current recommendations for vitamin D intake is needed.
Many otherwise healthy children and adolescents have low vitamin D levels, which may put them at risk for bone diseases such as rickets. African American children, children above age nine and with low dietary vitamin D intake were the most likely to have low levels of vitamin D in their blood, according to researchers from The Children’s Hospital of Philadelphia.
A study in the current issue of the American Journal of Clinical Nutrition measured blood levels of vitamin D in 382 healthy children between six years and 21 years of age living in the northeastern U.S. Researchers assessed dietary and supplemental vitamin D intake, as well as body mass, and found that more than half of the children had low blood levels of vitamin D. Of the subjects, 55 percent of the children had inadequate vitamin D blood levels and 68 percent overall had low blood levels of the vitamin in the wintertime.
“The best indicator of a person’s vitamin D status is the blood level of a vitamin D compound called 25-hydroxyvitamin D,” said Babette Zemel, Ph.D., a nutritional anthropologist at Children’s Hospital and primary investigator of this study. “Vitamin D deficiency remains an under-recognized problem overall, and is not well studied in children.”
Vitamin D is crucial for musculoskeletal health. The primary dietary source of the vitamin is fortified milk, but the best way to increase vitamin D levels is from exposure to sunshine. Severe deficits in vitamin D may lead to muscle weakness, defective bone mineralization and rickets. In addition to musculoskeletal effects, vitamin D is important for immune function, and low blood levels of the vitamin may contribute to diseases such as hypertension, cancer, multiple sclerosis and type 1 diabetes. Decreased blood levels of vitamin D have also been linked to obesity.
Further study is needed to determine the appropriate blood levels of vitamin D in children, said Dr. Zemel, who added that a review of the current recommendations for vitamin D intake is needed.
A spoonful of sugar helps your waistline go down
New study challenges conventional thinking that high carbohydrate, low fat slimming plan should contain little or no added sugar (sucrose).
A team of scientists at Queen Margaret University, Edinburgh has found that a low-fat, high-carbohydrate diet (containing sucrose) combined with physical activity achieved the greatest health benefits in overweight subjects. The study, which will be published in the August issue of International Journal of Food Sciences and Nutrition, provides evidence that the exclusion of sucrose, as is normally advocated in a weight loss diet, is not necessary to achieve weight reduction. In fact, the palatability of sucrose may even help dieters stick to their eating plans.
As part of a 12-week programme, 69 overweight women (average age 41 years; average body mass index [BMI] 32 kg/m2) were given advice on either diet, physical activity or both. A fourth group acting as the ‘control’ received no advice. Measures of body fat and markers of heart disease risk (such as waist circumference and cholesterol levels) were collected at the beginning and end of the trial.
The advice followed healthy eating guidelines and recommended:
- a reduced daily calorie intake, which was low in fat (35% of calorie intake) and high in carbohydrates (55% of calorie intake)
- that one tenth of their total calorie intake included sugar - around the average for a British adult. To achieve this goal, subjects were advised to include high carbohydrate snacks such as low fat cereal bars and low fat yogurts (containing at least 20g sugar) between two and four times per day, depending on their energy needs.
- an increase in activity levels focused on including sixty minutes of brisk walking per day.
Writing in the International Journal of Food Sciences and Nutrition, the researchers noted that after three months, the group combining the sugar-containing diet and activity changes recorded the greatest positive health outcomes, compared with diet or exercise alone. Significant reductions were observed in body weight (4.7% loss), waist circumference and percentage body fat. Measures of blood fats (total cholesterol and LDL) had also significantly improved.
‘This research contributes to the growing body of evidence that an effective way to lose weight is by adhering to a high-carbohydrate, low-fat diet and by being physically active.’ commented Dr Drummond, adding ‘ it also provides evidence that the exclusion of sucrose, as is normally advocated in a weight loss diet, is not necessary to achieve weight reduction.’
Part of its effectiveness may be due to the palatability of sucrose, making it easier to stick to the diet. As Dr Drummond points out ‘Compliance with this palatable low fat diet was excellent and when combined with increased physical activity resulted in significant improvements in body composition for this group of overweight women.’ This study highlights the need for dietary advice to accompany increased physical activity in order to achieve weight loss. It also demonstrates that a low-fat, high-carbohydrate, sucrose-containing diet combined with increased exercise can be effective for slimming. Further studies are now required to investigate which methods will motivate overweight individuals to adopt these lifestyle changes.
A team of scientists at Queen Margaret University, Edinburgh has found that a low-fat, high-carbohydrate diet (containing sucrose) combined with physical activity achieved the greatest health benefits in overweight subjects. The study, which will be published in the August issue of International Journal of Food Sciences and Nutrition, provides evidence that the exclusion of sucrose, as is normally advocated in a weight loss diet, is not necessary to achieve weight reduction. In fact, the palatability of sucrose may even help dieters stick to their eating plans.
As part of a 12-week programme, 69 overweight women (average age 41 years; average body mass index [BMI] 32 kg/m2) were given advice on either diet, physical activity or both. A fourth group acting as the ‘control’ received no advice. Measures of body fat and markers of heart disease risk (such as waist circumference and cholesterol levels) were collected at the beginning and end of the trial.
The advice followed healthy eating guidelines and recommended:
- a reduced daily calorie intake, which was low in fat (35% of calorie intake) and high in carbohydrates (55% of calorie intake)
- that one tenth of their total calorie intake included sugar - around the average for a British adult. To achieve this goal, subjects were advised to include high carbohydrate snacks such as low fat cereal bars and low fat yogurts (containing at least 20g sugar) between two and four times per day, depending on their energy needs.
- an increase in activity levels focused on including sixty minutes of brisk walking per day.
Writing in the International Journal of Food Sciences and Nutrition, the researchers noted that after three months, the group combining the sugar-containing diet and activity changes recorded the greatest positive health outcomes, compared with diet or exercise alone. Significant reductions were observed in body weight (4.7% loss), waist circumference and percentage body fat. Measures of blood fats (total cholesterol and LDL) had also significantly improved.
‘This research contributes to the growing body of evidence that an effective way to lose weight is by adhering to a high-carbohydrate, low-fat diet and by being physically active.’ commented Dr Drummond, adding ‘ it also provides evidence that the exclusion of sucrose, as is normally advocated in a weight loss diet, is not necessary to achieve weight reduction.’
Part of its effectiveness may be due to the palatability of sucrose, making it easier to stick to the diet. As Dr Drummond points out ‘Compliance with this palatable low fat diet was excellent and when combined with increased physical activity resulted in significant improvements in body composition for this group of overweight women.’ This study highlights the need for dietary advice to accompany increased physical activity in order to achieve weight loss. It also demonstrates that a low-fat, high-carbohydrate, sucrose-containing diet combined with increased exercise can be effective for slimming. Further studies are now required to investigate which methods will motivate overweight individuals to adopt these lifestyle changes.
Link between tomatoes and reduced cancer risk
FDA finds possible link between tomatoes and reduced cancer risk
A U.S. Food and Drug Administration (FDA) review has found only limited evidence for an association between eating tomatoes and a decreased risk of certain cancers, according to an article published online July 10 in the Journal of the National Cancer Institute.
Several studies have reported an association between the consumption of tomatoes or lycopene, an antioxidant that gives tomatoes their red hue, and a decreased risk of some cancers, particularly prostate cancer. In order for foods and dietary supplements to be labeled with such health claims, the FDA must review and approve these claims based on the available scientific evidence.
In a review article, Claudine Kavanaugh, Ph.D., of the FDA in College Park, Md., and colleagues describe the agency’s November 2005 evaluation of the scientific evidence linking tomatoes or tomato-based foods, lycopene, and reduced cancer risk.
Their review found very limited evidence for associations between tomato consumption and reduced risk of prostate, ovarian, gastric, and pancreatic cancers. Based on this assessment, the FDA decided to allow qualified health claims for a very limited association between tomatoes and these four cancers. Their analysis found no credible evidence that lycopene, either in food or in a dietary supplement, was associated with reduced risk of any of the cancers evaluated.
For prostate cancer, for example, the FDA issued this statement: “Very limited and preliminary scientific research suggests that eating one-half to one cup of tomatoes and/or tomato sauce a week may reduce the risk of prostate cancer. [The] FDA concludes that there is little scientific evidence supporting this claim.”
In one of the accompanying editorials, Paul Coates, Ph.D., of the National Institutes of Health in Bethesda, Md., discusses some of the issues the FDA had to contend with in conducting their review, such as the limited number of available clinical trials and the challenge of communicating to the public the subtleties of the FDA’s decision.
“Neither of these concerns, however, diminishes the importance of using evidence-based review principles to evaluate important diet-health relationships. In fact, it may be argued that evaluating a diet-health relationship is precisely the circumstance in which systematic review techniques can be most appropriate and effective because they are transparent and objective, and the search and review strategies could be exactly reproduced by others,” Coates writes.
In the second editorial, Edward Giovannucci, M.D., Sc.D., of the Harvard School of Public Health in Boston suggests that the widespread use of PSA (prostate-specific antigen) screening may influence the data on the association between tomato and lycopene consumption and prostate cancer risk.
“Given the complexities of studying the relationship between tomato or lycopene intake and prostate cancer risk, both in terms of the exposures and the outcome, one should not be too surprised that no firm conclusion of benefit would be made in the FDA review…Although it may be premature to espouse increased consumption of tomato sauce or lycopene for prostate cancer prevention, this area of research remains promising,” Giovannucci writes.
A U.S. Food and Drug Administration (FDA) review has found only limited evidence for an association between eating tomatoes and a decreased risk of certain cancers, according to an article published online July 10 in the Journal of the National Cancer Institute.
Several studies have reported an association between the consumption of tomatoes or lycopene, an antioxidant that gives tomatoes their red hue, and a decreased risk of some cancers, particularly prostate cancer. In order for foods and dietary supplements to be labeled with such health claims, the FDA must review and approve these claims based on the available scientific evidence.
In a review article, Claudine Kavanaugh, Ph.D., of the FDA in College Park, Md., and colleagues describe the agency’s November 2005 evaluation of the scientific evidence linking tomatoes or tomato-based foods, lycopene, and reduced cancer risk.
Their review found very limited evidence for associations between tomato consumption and reduced risk of prostate, ovarian, gastric, and pancreatic cancers. Based on this assessment, the FDA decided to allow qualified health claims for a very limited association between tomatoes and these four cancers. Their analysis found no credible evidence that lycopene, either in food or in a dietary supplement, was associated with reduced risk of any of the cancers evaluated.
For prostate cancer, for example, the FDA issued this statement: “Very limited and preliminary scientific research suggests that eating one-half to one cup of tomatoes and/or tomato sauce a week may reduce the risk of prostate cancer. [The] FDA concludes that there is little scientific evidence supporting this claim.”
In one of the accompanying editorials, Paul Coates, Ph.D., of the National Institutes of Health in Bethesda, Md., discusses some of the issues the FDA had to contend with in conducting their review, such as the limited number of available clinical trials and the challenge of communicating to the public the subtleties of the FDA’s decision.
“Neither of these concerns, however, diminishes the importance of using evidence-based review principles to evaluate important diet-health relationships. In fact, it may be argued that evaluating a diet-health relationship is precisely the circumstance in which systematic review techniques can be most appropriate and effective because they are transparent and objective, and the search and review strategies could be exactly reproduced by others,” Coates writes.
In the second editorial, Edward Giovannucci, M.D., Sc.D., of the Harvard School of Public Health in Boston suggests that the widespread use of PSA (prostate-specific antigen) screening may influence the data on the association between tomato and lycopene consumption and prostate cancer risk.
“Given the complexities of studying the relationship between tomato or lycopene intake and prostate cancer risk, both in terms of the exposures and the outcome, one should not be too surprised that no firm conclusion of benefit would be made in the FDA review…Although it may be premature to espouse increased consumption of tomato sauce or lycopene for prostate cancer prevention, this area of research remains promising,” Giovannucci writes.
More Meat = More Breast Cancer
Study finds western-style 'meat-sweet' diet increases risk of breast cancer in postmenopausal women
A new study finds that the more “western” the diet -- marked by red meat, starches and sweets -- the greater the risk for breast cancer among postmenopausal Chinese women. According to researchers who conducted the analysis at Fox Chase Cancer Center in Philadelphia, Harvard University, Shanghai Cancer Institute, and Vanderbilt University, the findings mark the first time a specific association between a western diet and breast cancer has been identified in Asian women.
The study, published in the July issue of Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research, is the latest set of findings derived from the Shanghai Breast Cancer Study, conducted in the 1990s by Wei Zheng, M.D., Ph.D., M.P.H, and colleagues at Vanderbilt University. The Fox Chase researchers identified dietary habits among women in the study based on their reported eating habits, classifying them as either “meat-sweet” or “vegetable-soy” eaters.
“The Shanghai data gave us a unique look at a population of Chinese women who were beginning to adopt more western-style eating habits,” said, Marilyn Tseng, Ph.D. associate member in the population science division at Fox Chase. “We found an association between a western-style diet and breast cancer was pronounced in postmenopausal women, especially heavier women with estrogen receptor-positive tumors.”
Breast cancers marked by the excessive production of estrogen receptors (ER+ breast cancers) form the majority of breast cancers and are often associated with obesity. According to Tseng, there seems to be a specific interaction between obesity and western cuisine among postmenopausal women that drives breast cancer, although the study did not offer a specific mechanism.
Tseng and her colleagues examined cases of women from the Shanghai Breast Cancer Study, 25 to 64 years of age, who were newly diagnosed with breast cancer from August 1996 to March 1998. Controls were selected from the Shanghai Resident Registry of permanent residents in urban Shanghai.
Through in-person interviews with the Shanghai study participants and residents of Shanghai, researchers established the existence of two primary dietary patterns – a“meat-sweet” diet and a “vegetable-soy” diet. The “meat-sweet” diet is characterized by various meats, primarily pork but also poultry, organ meats, beef and lamb, and shrimp, saltwater fish, and shellfish, as well as candy, dessert, bread, and milk. The “vegetable-soy” pattern is associated with various vegetables, soy-based products, and freshwater fish.
Of 1,602 breast cancer cases identified during the study period, in-person interviews were completed for 1,459 (91.1%). In-person interviews were completed for 1,556 (90.3%) of the 1,724 control group participants.
The “meat-sweet” pattern was significantly associated with increased risk of breast cancer among overweight postmenopausal women. Specifically, high intake of the “meat-sweet” pattern was associated with a greater than twofold increased risk of ER+ breast cancer among these women. The results showed no overall association of breast cancer risk with the “vegetable-soy” pattern.
“Our study suggests the possibility that the “meat-sweet” pattern interacts with obesity to increase breast cancer risk,” Tseng said. “Low consumption of a western dietary pattern plus successful weight control may protect against breast cancer in a traditionally low-risk Asian population that is poised to more broadly adopt foods characteristic of western societies.”
A new study finds that the more “western” the diet -- marked by red meat, starches and sweets -- the greater the risk for breast cancer among postmenopausal Chinese women. According to researchers who conducted the analysis at Fox Chase Cancer Center in Philadelphia, Harvard University, Shanghai Cancer Institute, and Vanderbilt University, the findings mark the first time a specific association between a western diet and breast cancer has been identified in Asian women.
The study, published in the July issue of Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research, is the latest set of findings derived from the Shanghai Breast Cancer Study, conducted in the 1990s by Wei Zheng, M.D., Ph.D., M.P.H, and colleagues at Vanderbilt University. The Fox Chase researchers identified dietary habits among women in the study based on their reported eating habits, classifying them as either “meat-sweet” or “vegetable-soy” eaters.
“The Shanghai data gave us a unique look at a population of Chinese women who were beginning to adopt more western-style eating habits,” said, Marilyn Tseng, Ph.D. associate member in the population science division at Fox Chase. “We found an association between a western-style diet and breast cancer was pronounced in postmenopausal women, especially heavier women with estrogen receptor-positive tumors.”
Breast cancers marked by the excessive production of estrogen receptors (ER+ breast cancers) form the majority of breast cancers and are often associated with obesity. According to Tseng, there seems to be a specific interaction between obesity and western cuisine among postmenopausal women that drives breast cancer, although the study did not offer a specific mechanism.
Tseng and her colleagues examined cases of women from the Shanghai Breast Cancer Study, 25 to 64 years of age, who were newly diagnosed with breast cancer from August 1996 to March 1998. Controls were selected from the Shanghai Resident Registry of permanent residents in urban Shanghai.
Through in-person interviews with the Shanghai study participants and residents of Shanghai, researchers established the existence of two primary dietary patterns – a“meat-sweet” diet and a “vegetable-soy” diet. The “meat-sweet” diet is characterized by various meats, primarily pork but also poultry, organ meats, beef and lamb, and shrimp, saltwater fish, and shellfish, as well as candy, dessert, bread, and milk. The “vegetable-soy” pattern is associated with various vegetables, soy-based products, and freshwater fish.
Of 1,602 breast cancer cases identified during the study period, in-person interviews were completed for 1,459 (91.1%). In-person interviews were completed for 1,556 (90.3%) of the 1,724 control group participants.
The “meat-sweet” pattern was significantly associated with increased risk of breast cancer among overweight postmenopausal women. Specifically, high intake of the “meat-sweet” pattern was associated with a greater than twofold increased risk of ER+ breast cancer among these women. The results showed no overall association of breast cancer risk with the “vegetable-soy” pattern.
“Our study suggests the possibility that the “meat-sweet” pattern interacts with obesity to increase breast cancer risk,” Tseng said. “Low consumption of a western dietary pattern plus successful weight control may protect against breast cancer in a traditionally low-risk Asian population that is poised to more broadly adopt foods characteristic of western societies.”
Tuesday, July 10, 2007
Antibiotics don't stop new urinary tract infections
Antibiotics don't prevent future urinary tract infections, may cause resistance in future infections
After a first childhood urinary tract infection (UTI), daily antibiotics may not prevent another such infection, and may actually increase the risk that the next urinary tract infection is caused by resistant bacteria, according to a new study in the July 11 issue of the Journal of the American Medical Association.
In the first large study of children diagnosed with UTI in a primary care pediatric setting, researchers from The Children’s Hospital of Philadelphia reviewed the electronic health records of 74,974 children with at least two clinic visits in The Children’s Hospital of Philadelphia’s pediatric healthcare network between July 2001 and May 2006. The researchers found that 611 children had a first urinary tract infection and 83 had a recurrent UTI. Children between ages three and five, Caucasians, and those with severe vesicoureteral reflux had the highest risk of recurrent UTI. Receiving a daily dose of preventive antibiotics was not associated with a lower risk of recurrent UTI.
“The majority of children with first UTI were female, Caucasian and two through six years old. Most did not have an imaging study performed and did not receive daily antibiotics to prevent infections,” said Patrick Conway, M.D. M.Sc., primary investigator of the study. “We found that daily antibiotic treatment was not associated with a decreased risk of recurrent UTIs, but was associated with an increased risk of resistant infections.” Currently at Cincinnati Children’s Hospital Medical Center, Dr. Conway conducted the research while at The Children’s Hospital of Philadelphia and a Robert Wood Johnson Clinical Scholar at the University of Pennsylvania.
“More definitive studies, such as clinical trials, are needed to look at this issue.” said Ron Keren, M.D., M.P.H., a general pediatrician at The Children’s Hospital of Philadelphia and senior author on this study. “But given these findings, it is appropriate for pediatricians to discuss with families the risks and unclear benefits of daily preventive antibiotic treatment after a child has had a first UTI.”
UTIs are common in children. In fact, of all the children born in one year, 70,000 to 180,000 will have a UTI by age six.
The American Academy of Pediatrics (AAP) practice guideline for management of children after a first UTI recommends an imaging study to evaluate the presence and degree of vesicoureteral reflux (VUR), a condition found in approximately 30 to 40 percent of children who have had a UTI. If the child has VUR, daily antibiotic treatment is recommended in an attempt to prevent recurrent UTIs.
Vesicoureteral reflux (VUR) occurs when urine in the bladder flows back into the ureters or kidneys during urination. It is thought that a child who has VUR is at risk for developing recurrent kidney infections, which, over time, can cause damage to the kidneys. However, Dr. Conway summarized, “The majority of children have lower grade VUR and this lower grade VUR was not associated with an increased risk of recurrent UTI in our study.”
After a first childhood urinary tract infection (UTI), daily antibiotics may not prevent another such infection, and may actually increase the risk that the next urinary tract infection is caused by resistant bacteria, according to a new study in the July 11 issue of the Journal of the American Medical Association.
In the first large study of children diagnosed with UTI in a primary care pediatric setting, researchers from The Children’s Hospital of Philadelphia reviewed the electronic health records of 74,974 children with at least two clinic visits in The Children’s Hospital of Philadelphia’s pediatric healthcare network between July 2001 and May 2006. The researchers found that 611 children had a first urinary tract infection and 83 had a recurrent UTI. Children between ages three and five, Caucasians, and those with severe vesicoureteral reflux had the highest risk of recurrent UTI. Receiving a daily dose of preventive antibiotics was not associated with a lower risk of recurrent UTI.
“The majority of children with first UTI were female, Caucasian and two through six years old. Most did not have an imaging study performed and did not receive daily antibiotics to prevent infections,” said Patrick Conway, M.D. M.Sc., primary investigator of the study. “We found that daily antibiotic treatment was not associated with a decreased risk of recurrent UTIs, but was associated with an increased risk of resistant infections.” Currently at Cincinnati Children’s Hospital Medical Center, Dr. Conway conducted the research while at The Children’s Hospital of Philadelphia and a Robert Wood Johnson Clinical Scholar at the University of Pennsylvania.
“More definitive studies, such as clinical trials, are needed to look at this issue.” said Ron Keren, M.D., M.P.H., a general pediatrician at The Children’s Hospital of Philadelphia and senior author on this study. “But given these findings, it is appropriate for pediatricians to discuss with families the risks and unclear benefits of daily preventive antibiotic treatment after a child has had a first UTI.”
UTIs are common in children. In fact, of all the children born in one year, 70,000 to 180,000 will have a UTI by age six.
The American Academy of Pediatrics (AAP) practice guideline for management of children after a first UTI recommends an imaging study to evaluate the presence and degree of vesicoureteral reflux (VUR), a condition found in approximately 30 to 40 percent of children who have had a UTI. If the child has VUR, daily antibiotic treatment is recommended in an attempt to prevent recurrent UTIs.
Vesicoureteral reflux (VUR) occurs when urine in the bladder flows back into the ureters or kidneys during urination. It is thought that a child who has VUR is at risk for developing recurrent kidney infections, which, over time, can cause damage to the kidneys. However, Dr. Conway summarized, “The majority of children have lower grade VUR and this lower grade VUR was not associated with an increased risk of recurrent UTI in our study.”
Birth weight affects adult health and success
Birth weight has significant and lasting effects, a new study finds. Weighing less than 5.5 pounds at birth increases the probability of dropping out of high school by one-third, reduces yearly earnings by about 15 percent and burdens people in their 30s and 40s with the health of someone who is 12 years older.
The study, presented May 22 in Washington, D.C. at the National Summit on America's Children, is the first to link birth weight with adult health and socioeconomic success using a full, nationally representative sample of the U.S. population. It is based on an analysis of more than 35 years of data on more than 12,000 individuals from the Panel Study of Income Dynamics, conducted since 1968 by the University of Michigan Institute for Social Research (ISR).
Funded by the National Institute on Aging, the analysis includes data from the original study families, plus their descendants who have gone on to form families of their own. Because of the study's unique genealogical design, the researchers were able to compare outcomes for siblings to isolate the impact of low birth weight apart from other common family conditions siblings share.
According to the authors, economists Rucker Johnson at the University of California, Berkeley, and Robert Schoeni at U-M, the study provides the most detailed look to date at how well-being and disadvantage are transmitted across generations within families.
"The poor economic status of parents at the time of pregnancy leads to worse birth outcomes for their children," Johnson and Schoeni write in a working paper from the U-M National Poverty Center. "In turn, these negative birth outcomes have harmful effects on the children's cognitive development, health, and human capital accumulation, and also health and economic status in adulthood. These effects then get passed on to the subsequent generation when the children, who are now adults, have their own children."
Among the key findings:
• Compared to their normal birth weight siblings, low birth-weight children are 30 percent less likely to be in excellent or very good health in childhood. They also score significantly lower on reading, passage comprehension, and math achievement tests. Low birth-weight children are roughly one-third more likely to drop out of high school relative other children.
• Low birth weight has significant negative effects on adult health, equivalent to being 12 years older in one's 30s and 40s. Weighing less than 5.5 pounds at birth increases the probability of being in fair or poor health as an adult by over 70 percent. Not only does birth weight have large and lasting effects across the life course, the researchers note, but its effects become larger later in life. For example, low birth weight children are nearly twice as likely as their normal birth-weight siblings to be in problematic health by ages 37-52 (23 percent versus 12 percent).
The study, presented May 22 in Washington, D.C. at the National Summit on America's Children, is the first to link birth weight with adult health and socioeconomic success using a full, nationally representative sample of the U.S. population. It is based on an analysis of more than 35 years of data on more than 12,000 individuals from the Panel Study of Income Dynamics, conducted since 1968 by the University of Michigan Institute for Social Research (ISR).
Funded by the National Institute on Aging, the analysis includes data from the original study families, plus their descendants who have gone on to form families of their own. Because of the study's unique genealogical design, the researchers were able to compare outcomes for siblings to isolate the impact of low birth weight apart from other common family conditions siblings share.
According to the authors, economists Rucker Johnson at the University of California, Berkeley, and Robert Schoeni at U-M, the study provides the most detailed look to date at how well-being and disadvantage are transmitted across generations within families.
"The poor economic status of parents at the time of pregnancy leads to worse birth outcomes for their children," Johnson and Schoeni write in a working paper from the U-M National Poverty Center. "In turn, these negative birth outcomes have harmful effects on the children's cognitive development, health, and human capital accumulation, and also health and economic status in adulthood. These effects then get passed on to the subsequent generation when the children, who are now adults, have their own children."
Among the key findings:
• Compared to their normal birth weight siblings, low birth-weight children are 30 percent less likely to be in excellent or very good health in childhood. They also score significantly lower on reading, passage comprehension, and math achievement tests. Low birth-weight children are roughly one-third more likely to drop out of high school relative other children.
• Low birth weight has significant negative effects on adult health, equivalent to being 12 years older in one's 30s and 40s. Weighing less than 5.5 pounds at birth increases the probability of being in fair or poor health as an adult by over 70 percent. Not only does birth weight have large and lasting effects across the life course, the researchers note, but its effects become larger later in life. For example, low birth weight children are nearly twice as likely as their normal birth-weight siblings to be in problematic health by ages 37-52 (23 percent versus 12 percent).
Friday, July 6, 2007
Fitness may reduce inflammation
Although a number of studies have suggested that regular exercise reduces inflammation – a condition that is predictive of cardiovascular and other diseases, such as diabetes – it’s still not clear whether there is a definitive link. And if such a link exists, the nature of the relationship is by no means fully understood.
A recent study by kinesiology and community health researchers at the University of Illinois provides new evidence that may help explain some of the underlying biological mechanisms that take place as the result of regular exercise. According to the researchers, that knowledge could potentially lead to a better understanding of the relationship between exercise and inflammation.
The objective of their research was to examine the independent effect of parasympathetic tone – in this case, determined by assessing heart-rate recovery after exercise – on circulating levels of C-reactive protein (CRP). Parasympathetic tone and its inverse function – sympathetic tone – are components of the autonomic nervous system. CRP, which is secreted by the liver, circulates in the bloodstream and is a biomarker for inflammation in the body.
“The sympathetic nervous system speeds things up, and the parasympathetic slows things down,” said Victoria J. Vieira, a predoctoral fellow in kinesiology and community health and in nutritional sciences, and the primary author and designer of the study, published in a recent issue of the Journal of the American Geriatrics Society. “So when you’re exercising, your sympathetic nervous system will be on, increasing your heart rate, your respiration, etc. Once you stop, your body always tries to get back to homeostasis. So the parasympathetic nervous system kicks in to get everything back down to baseline levels.”
Co-author and kinesiology and community health professor Jeffrey A. Woods said cardiologists are already routinely gauging CRP levels in much the same way they look at lipids panels to assess cholesterol levels.
“Certainly, that’s being done in the cardiovascular disease realm, but I think (it may be effectively used as a monitor) for other diseases, such as Alzheimer’s, diabetes and metabolic syndrome,” he said.
Woods said the main question motivating the current research was, “What factors are related to CRP in the elderly?”
“We’ve known that as people age, their CRP levels go up,” Vieira said. “That’s one of the reasons why older individuals are more prone to develop inflammation-related diseases such as diabetes and heart disease. So we just wanted to look at what’s predicting those levels of CRP in an average older population that is relatively healthy.”
Perhaps the most notable result of the study, according to the researchers, relates to heart-rate recovery following exercise.
“The quicker the individuals were able to get back to their resting heart rate after a strenuous exercise test was inversely related to their CRP,” Vieira said. “In other words, individuals who had better parasympathetic tone had lower levels of inflammation.
“And the reason we’re excited about this is that exercise is a great way to improve parasympathetic tone. When you exercise – that is the sympathetic/parasympathetic communication – your sympathetic goes up, and when you stop exercising, your parasympathetic kicks in to bring you back to normal. An untrained person will take a while to get their heart rate back down to resting. A trained person’s heart rate will come back down very quickly.”
The cross-sectional study focused on baseline test results from 132 sedentary, independently living individuals aged 60 to 83 (47 males; 85 females) who had been recruited to participate in the Immune Function Intervention Trial (ImFIT), a randomized longitudinal trial designed by Woods and funded by the National Institute on Aging to examine the relationship between exercise and immune function.
Participants included only individuals who did not take medications that included corticosteroids, which could interfere with immune measurements. Smokers and/or those with severe arthritis, a history of cancer or inflammatory disease, chronic obstructive pulmonary disorder, uncontrolled diabetes mellitus, congestive heart failure, recent illness or vaccination, or a positive stress test were excluded.
The physical fitness of subjects was assessed through a battery of tests that measured such variables as fatigue, blood pressure, oxygen intake and carbon dioxide elimination and heart-rate recovery in conjunction with exercise on a walking treadmill. Tests also were administered to determine the subjects’ levels of physical activity, physical fitness, emotional stress and body composition (bone density and body fat). Blood samples also were drawn to measure CRP levels.
“The major criterion we were looking at was their fitness level,” Vieira said. “A strength of our study is that we have very good data on their fitness levels.”
And while other studies have explored the relationship between exercise and inflammation, another unique aspect of the U. of I. research, Vieira said, is that “no other studies have adjusted for fitness and body fat percentages simultaneously to really get at that question, ‘Is exercise independently reducing CRP levels, or is it modulated through a decrease in adiposity (body fat)?’ ”
Because the study was cross-sectional – meaning the researchers essentially took a snapshot of the participants’ reactions and measurements at a single, fixed point only – Vieira said it was important to note that “we can’t say anything about cause and effect relationships.”
However, Woods said, “it gives you some idea of what factors are related, and then you test those in a more rigorous manner.”
Vieira said the research “certainly suggests that fitness may be associated with a decrease in inflammation even independent of body fat and several things, and the mechanism may involve a parasympathetic anti-inflammatory reflex.”
“We know inflammation is bad. We know it increases as we age, with stress and other things,” she said. “So if we can decrease that to protect ourselves somehow by just adopting a physically active lifestyle, that’s definitely an advantage.”
And while the study confirms the conclusions of previous research by others indicating that high body fat is related to high inflammation and high fitness to low inflammation, “the unique part of this paper is that controlling for those, we also show that high parasympathetic tone is related to low inflammation,” Woods said.
“And it’s even independent of their fitness level,” Vieira interjected.
“Fitness, fatness and parasympathetic tone appear to be important,” Woods said, summing up the findings. “And at least according to our results, parasympathetic tone might even be more important than those other factors.”
A recent study by kinesiology and community health researchers at the University of Illinois provides new evidence that may help explain some of the underlying biological mechanisms that take place as the result of regular exercise. According to the researchers, that knowledge could potentially lead to a better understanding of the relationship between exercise and inflammation.
The objective of their research was to examine the independent effect of parasympathetic tone – in this case, determined by assessing heart-rate recovery after exercise – on circulating levels of C-reactive protein (CRP). Parasympathetic tone and its inverse function – sympathetic tone – are components of the autonomic nervous system. CRP, which is secreted by the liver, circulates in the bloodstream and is a biomarker for inflammation in the body.
“The sympathetic nervous system speeds things up, and the parasympathetic slows things down,” said Victoria J. Vieira, a predoctoral fellow in kinesiology and community health and in nutritional sciences, and the primary author and designer of the study, published in a recent issue of the Journal of the American Geriatrics Society. “So when you’re exercising, your sympathetic nervous system will be on, increasing your heart rate, your respiration, etc. Once you stop, your body always tries to get back to homeostasis. So the parasympathetic nervous system kicks in to get everything back down to baseline levels.”
Co-author and kinesiology and community health professor Jeffrey A. Woods said cardiologists are already routinely gauging CRP levels in much the same way they look at lipids panels to assess cholesterol levels.
“Certainly, that’s being done in the cardiovascular disease realm, but I think (it may be effectively used as a monitor) for other diseases, such as Alzheimer’s, diabetes and metabolic syndrome,” he said.
Woods said the main question motivating the current research was, “What factors are related to CRP in the elderly?”
“We’ve known that as people age, their CRP levels go up,” Vieira said. “That’s one of the reasons why older individuals are more prone to develop inflammation-related diseases such as diabetes and heart disease. So we just wanted to look at what’s predicting those levels of CRP in an average older population that is relatively healthy.”
Perhaps the most notable result of the study, according to the researchers, relates to heart-rate recovery following exercise.
“The quicker the individuals were able to get back to their resting heart rate after a strenuous exercise test was inversely related to their CRP,” Vieira said. “In other words, individuals who had better parasympathetic tone had lower levels of inflammation.
“And the reason we’re excited about this is that exercise is a great way to improve parasympathetic tone. When you exercise – that is the sympathetic/parasympathetic communication – your sympathetic goes up, and when you stop exercising, your parasympathetic kicks in to bring you back to normal. An untrained person will take a while to get their heart rate back down to resting. A trained person’s heart rate will come back down very quickly.”
The cross-sectional study focused on baseline test results from 132 sedentary, independently living individuals aged 60 to 83 (47 males; 85 females) who had been recruited to participate in the Immune Function Intervention Trial (ImFIT), a randomized longitudinal trial designed by Woods and funded by the National Institute on Aging to examine the relationship between exercise and immune function.
Participants included only individuals who did not take medications that included corticosteroids, which could interfere with immune measurements. Smokers and/or those with severe arthritis, a history of cancer or inflammatory disease, chronic obstructive pulmonary disorder, uncontrolled diabetes mellitus, congestive heart failure, recent illness or vaccination, or a positive stress test were excluded.
The physical fitness of subjects was assessed through a battery of tests that measured such variables as fatigue, blood pressure, oxygen intake and carbon dioxide elimination and heart-rate recovery in conjunction with exercise on a walking treadmill. Tests also were administered to determine the subjects’ levels of physical activity, physical fitness, emotional stress and body composition (bone density and body fat). Blood samples also were drawn to measure CRP levels.
“The major criterion we were looking at was their fitness level,” Vieira said. “A strength of our study is that we have very good data on their fitness levels.”
And while other studies have explored the relationship between exercise and inflammation, another unique aspect of the U. of I. research, Vieira said, is that “no other studies have adjusted for fitness and body fat percentages simultaneously to really get at that question, ‘Is exercise independently reducing CRP levels, or is it modulated through a decrease in adiposity (body fat)?’ ”
Because the study was cross-sectional – meaning the researchers essentially took a snapshot of the participants’ reactions and measurements at a single, fixed point only – Vieira said it was important to note that “we can’t say anything about cause and effect relationships.”
However, Woods said, “it gives you some idea of what factors are related, and then you test those in a more rigorous manner.”
Vieira said the research “certainly suggests that fitness may be associated with a decrease in inflammation even independent of body fat and several things, and the mechanism may involve a parasympathetic anti-inflammatory reflex.”
“We know inflammation is bad. We know it increases as we age, with stress and other things,” she said. “So if we can decrease that to protect ourselves somehow by just adopting a physically active lifestyle, that’s definitely an advantage.”
And while the study confirms the conclusions of previous research by others indicating that high body fat is related to high inflammation and high fitness to low inflammation, “the unique part of this paper is that controlling for those, we also show that high parasympathetic tone is related to low inflammation,” Woods said.
“And it’s even independent of their fitness level,” Vieira interjected.
“Fitness, fatness and parasympathetic tone appear to be important,” Woods said, summing up the findings. “And at least according to our results, parasympathetic tone might even be more important than those other factors.”
Thursday, July 5, 2007
A little dark chocolate = less blood pressure
Consumption of small amounts of dark chocolate associated with reduction in blood pressure
Eating about 30 calories a day of dark chocolate was associated with a lowering of blood pressure, without weight gain or other adverse effects, according to a study in the July 4 issue of JAMA.
Previous research has indicated that consumption of high amounts of cocoa-containing foods can lower blood pressure (BP), believed to be due to the action of the cocoa polyphenols (a group of chemical substances found in plants, some of which, such as the flavanols, are believed to be beneficial to health). “A particular concern is that the potential BP reduction contributed by the flavanols could be offset by the high sugar, fat and calorie intake with the cocoa products,” the authors write. The effect of low cocoa intake on BP is unclear.
Dirk Taubert, M.D., Ph.D., of University Hospital of Cologne, Germany, and colleagues assessed the effects of low regular amounts of cocoa on BP. The trial, conducted between January 2005 and December 2006, included 44 adults (age 56 through 73 years; 24 women, 20 men) with untreated upper-range prehypertension (BP 130/85 – 139/89) or stage 1 hypertension (BP 140/90 – 160/100). Participants were randomly assigned to receive for 18 weeks either 6.3 g (30 calories) per day of dark chocolate containing 30 mg polyphenols or matching polyphenol-free white chocolate.
The researchers found that from baseline to 18 weeks, dark chocolate intake reduced average systolic BP by −2.9 (1.6) mm Hg and diastolic BP by −1.9 (1.0) mm Hg without changes in body weight, plasma levels of lipids or glucose. Hypertension prevalence declined from 86 percent to 68 percent. Systolic and diastolic BP remained unchanged throughout the treatment period among those in the white chocolate group. Dark chocolate consumption resulted in the short-term appearance of cocoa phenols in plasma and increased vasodilatory S-nitrosoglutathione. There was no change in plasma biomarkers in the white chocolate group.
“Although the magnitude of the BP reduction was small, the effects are clinically noteworthy. On a population basis, it has been estimated that a 3-mm Hg reduction in systolic BP would reduce the relative risk of stroke mortality by 8 percent, of coronary artery disease mortality by 5 percent, and of all-cause mortality by 4 percent,” the authors write.
“The most intriguing finding of this study is that small amounts of commercial cocoa confectionary convey a similar BP-lowering potential compared with comprehensive dietary modifications that have proven efficacy to reduce cardiovascular event rate. Whereas long-term adherence to complex behavioral changes is often low and requires continuous counseling, adoption of small amounts of flavanol-rich cocoa into the habitual diet is a dietary modification that is easy to adhere to and therefore may be a promising behavioral approach to lower blood pressure in individuals with above-optimal blood pressure. Future studies should evaluate the effects of dark chocolate in other populations and evaluate long-term outcomes,” the authors conclude.
Eating about 30 calories a day of dark chocolate was associated with a lowering of blood pressure, without weight gain or other adverse effects, according to a study in the July 4 issue of JAMA.
Previous research has indicated that consumption of high amounts of cocoa-containing foods can lower blood pressure (BP), believed to be due to the action of the cocoa polyphenols (a group of chemical substances found in plants, some of which, such as the flavanols, are believed to be beneficial to health). “A particular concern is that the potential BP reduction contributed by the flavanols could be offset by the high sugar, fat and calorie intake with the cocoa products,” the authors write. The effect of low cocoa intake on BP is unclear.
Dirk Taubert, M.D., Ph.D., of University Hospital of Cologne, Germany, and colleagues assessed the effects of low regular amounts of cocoa on BP. The trial, conducted between January 2005 and December 2006, included 44 adults (age 56 through 73 years; 24 women, 20 men) with untreated upper-range prehypertension (BP 130/85 – 139/89) or stage 1 hypertension (BP 140/90 – 160/100). Participants were randomly assigned to receive for 18 weeks either 6.3 g (30 calories) per day of dark chocolate containing 30 mg polyphenols or matching polyphenol-free white chocolate.
The researchers found that from baseline to 18 weeks, dark chocolate intake reduced average systolic BP by −2.9 (1.6) mm Hg and diastolic BP by −1.9 (1.0) mm Hg without changes in body weight, plasma levels of lipids or glucose. Hypertension prevalence declined from 86 percent to 68 percent. Systolic and diastolic BP remained unchanged throughout the treatment period among those in the white chocolate group. Dark chocolate consumption resulted in the short-term appearance of cocoa phenols in plasma and increased vasodilatory S-nitrosoglutathione. There was no change in plasma biomarkers in the white chocolate group.
“Although the magnitude of the BP reduction was small, the effects are clinically noteworthy. On a population basis, it has been estimated that a 3-mm Hg reduction in systolic BP would reduce the relative risk of stroke mortality by 8 percent, of coronary artery disease mortality by 5 percent, and of all-cause mortality by 4 percent,” the authors write.
“The most intriguing finding of this study is that small amounts of commercial cocoa confectionary convey a similar BP-lowering potential compared with comprehensive dietary modifications that have proven efficacy to reduce cardiovascular event rate. Whereas long-term adherence to complex behavioral changes is often low and requires continuous counseling, adoption of small amounts of flavanol-rich cocoa into the habitual diet is a dietary modification that is easy to adhere to and therefore may be a promising behavioral approach to lower blood pressure in individuals with above-optimal blood pressure. Future studies should evaluate the effects of dark chocolate in other populations and evaluate long-term outcomes,” the authors conclude.
Tuesday, July 3, 2007
1 cigarette can lead to nicotine addiction
Kids show signs of addiction almost immediately
A new study published in the Archives of Pediatric and Adolescent Medicine shows that 10 percent of youth who become hooked on cigarettes are addicted within two days of first inhaling from a cigarette, and 25 percent are addicted within a month. The study found that adolescents who smoke even just a few cigarettes per month suffer withdrawal symptoms when deprived of nicotine, a startling finding that is contrary to long-held beliefs that only people with established smoking habits of at least five cigarettes per day experience such symptoms.
The study monitored 1,246 sixth-grade students in six Massachusetts communities over four years. Students were interviewed frequently about smoking and symptoms of addiction, such as difficulty quitting, strong urges to smoke, or nicotine withdrawal symptoms such as cravings, restlessness, irritability, and trouble concentrating. Of those who were hooked, half were already addicted by the time they were smoking seven cigarettes per month. As amazing as it may seem, some youth find they are unable to quit smoking after just a few cigarettes. This confirms an earlier study by the same researchers.
Recent research has revealed that the nicotine from one cigarette is enough to saturate the nicotine receptors in the human brain. “Laboratory experiments confirm that nicotine alters the structure and function of the brain within a day of the very first dose. In humans, nicotine-induced alterations in the brain can trigger addiction with the first cigarette,” commented Joseph R. DiFranza, MD, professor of family medicine & community health at the University of Massachusetts Medical School and leader of the UMMS research team. “Nobody expects to get addicted from smoking one cigarette.” Many smokers struggle for a lifetime trying to overcome nicotine addiction. The National Institutes of Health estimates that as many as 6.4 million children who are living today will die prematurely as adults because they began to smoke cigarettes during adolescence.
“While smoking one cigarette will keep withdrawal symptoms away for less than an hour in long-time smokers, novice smokers find that one cigarette suppresses withdrawal for weeks at a time,” explained Dr. DiFranza. “One dose of nicotine affects brain function long after the nicotine is gone from the body. The important lesson here is that youth have all the same symptoms of nicotine addiction as adults do, even though they may be smoking only a few cigarettes per month.”
Symptoms of nicotine addiction can appear when youth are smoking as little as one cigarette per month. At first, one cigarette will relieve the craving produced by nicotine withdrawal for weeks, but as tolerance to nicotine builds, the smoker finds that he or she must smoke ever more frequently to cope with withdrawal.
According to DiFranza, the addiction-related changes in the brain caused by nicotine are permanent and remain years after a smoker has quit. This explains why one cigarette can trigger an immediate relapse in an ex-smoker. It also explains why an ex-smoker who relapses after many years of abstinence cannot keep the craving away by smoking one cigarette per month. Unlike the newly addicted novice smoker, a newly relapsed smoker must smoke several cigarettes each day to cope with the craving.
A new study published in the Archives of Pediatric and Adolescent Medicine shows that 10 percent of youth who become hooked on cigarettes are addicted within two days of first inhaling from a cigarette, and 25 percent are addicted within a month. The study found that adolescents who smoke even just a few cigarettes per month suffer withdrawal symptoms when deprived of nicotine, a startling finding that is contrary to long-held beliefs that only people with established smoking habits of at least five cigarettes per day experience such symptoms.
The study monitored 1,246 sixth-grade students in six Massachusetts communities over four years. Students were interviewed frequently about smoking and symptoms of addiction, such as difficulty quitting, strong urges to smoke, or nicotine withdrawal symptoms such as cravings, restlessness, irritability, and trouble concentrating. Of those who were hooked, half were already addicted by the time they were smoking seven cigarettes per month. As amazing as it may seem, some youth find they are unable to quit smoking after just a few cigarettes. This confirms an earlier study by the same researchers.
Recent research has revealed that the nicotine from one cigarette is enough to saturate the nicotine receptors in the human brain. “Laboratory experiments confirm that nicotine alters the structure and function of the brain within a day of the very first dose. In humans, nicotine-induced alterations in the brain can trigger addiction with the first cigarette,” commented Joseph R. DiFranza, MD, professor of family medicine & community health at the University of Massachusetts Medical School and leader of the UMMS research team. “Nobody expects to get addicted from smoking one cigarette.” Many smokers struggle for a lifetime trying to overcome nicotine addiction. The National Institutes of Health estimates that as many as 6.4 million children who are living today will die prematurely as adults because they began to smoke cigarettes during adolescence.
“While smoking one cigarette will keep withdrawal symptoms away for less than an hour in long-time smokers, novice smokers find that one cigarette suppresses withdrawal for weeks at a time,” explained Dr. DiFranza. “One dose of nicotine affects brain function long after the nicotine is gone from the body. The important lesson here is that youth have all the same symptoms of nicotine addiction as adults do, even though they may be smoking only a few cigarettes per month.”
Symptoms of nicotine addiction can appear when youth are smoking as little as one cigarette per month. At first, one cigarette will relieve the craving produced by nicotine withdrawal for weeks, but as tolerance to nicotine builds, the smoker finds that he or she must smoke ever more frequently to cope with withdrawal.
According to DiFranza, the addiction-related changes in the brain caused by nicotine are permanent and remain years after a smoker has quit. This explains why one cigarette can trigger an immediate relapse in an ex-smoker. It also explains why an ex-smoker who relapses after many years of abstinence cannot keep the craving away by smoking one cigarette per month. Unlike the newly addicted novice smoker, a newly relapsed smoker must smoke several cigarettes each day to cope with the craving.
Antidepressants Not Linked to Birth Defects
Two research studies published today in The New England Journal of Medicine found taking SSRIs (selective serotonin reuptake inhibitors), anti-depression drugs, during pregnancy did not significantly increase the overall risk for most birth defects. However, each study found that taking SSRIs during pregnancy was associated with a small increase in the risk of certain rare birth defects – but they were different birth defects.
Dr. Michael Katz, acting Medical Director of the March of Dimes, said the studies show how important post-market surveillance is in assessing the safety of medications in pregnancy. During pre-approval, drugs are tested on relatively few subjects and only side effects with a large frequency are detected. Once approved, many people take the medication and even very rare side effects surface.
“Most prescription drugs are not tested on pregnant women,” said Dr. Katz. “So we must start monitoring the effects of these medications as soon as they reach consumers, and keep monitoring for as long as it takes to get good data on risks to mothers and babies.”
The March of Dimes recommends women discuss the potential risks and benefits of taking SSRIs during pregnancy with their doctors. Women who are taking an antidepressant should not stop taking their medications if they discover they are pregnant, but should immediately contact their health care provider. It may be dangerous to stop taking an antidepressant suddenly.
About 10 percent of pregnant women in the United States suffer from depression, some of it undiagnosed.
Previous studies have found that some SSRIs may increase the risk for other problems for babies, including:_
• Withdrawal symptoms in newborns;
• Pulmonary hypertension of the newborn (PPHN), a rare, but serious heart and lung disorder;
• Low birthweight or preterm delivery.
Dr. Michael Katz, acting Medical Director of the March of Dimes, said the studies show how important post-market surveillance is in assessing the safety of medications in pregnancy. During pre-approval, drugs are tested on relatively few subjects and only side effects with a large frequency are detected. Once approved, many people take the medication and even very rare side effects surface.
“Most prescription drugs are not tested on pregnant women,” said Dr. Katz. “So we must start monitoring the effects of these medications as soon as they reach consumers, and keep monitoring for as long as it takes to get good data on risks to mothers and babies.”
The March of Dimes recommends women discuss the potential risks and benefits of taking SSRIs during pregnancy with their doctors. Women who are taking an antidepressant should not stop taking their medications if they discover they are pregnant, but should immediately contact their health care provider. It may be dangerous to stop taking an antidepressant suddenly.
About 10 percent of pregnant women in the United States suffer from depression, some of it undiagnosed.
Previous studies have found that some SSRIs may increase the risk for other problems for babies, including:_
• Withdrawal symptoms in newborns;
• Pulmonary hypertension of the newborn (PPHN), a rare, but serious heart and lung disorder;
• Low birthweight or preterm delivery.
Head injury three times greater in HS football
Catastrophic head injury three times greater in high school vs. collegiate football players
Study finds 'unacceptably high percentage' of high schoolers who sustain catastrophic head injury play with residual effects of prior head injury
The incidence of catastrophic head injuries in football is dramatically higher at the high school level than at the college level, according to a study published in the July issue of The American Journal of Sports Medicine.
Catastrophic head injuries, which include brain bleeding and swelling, are rare and can be devastating. Athletes with major brain injuries may be left with permanent brain damage.
“High school football players have more than three times the risk of a catastrophic head injury than their college peers,” says lead author, Barry P. Boden, M.D., from the Orthopedic Center in Rockville, Md., and adjunct associate professor at the Uniform Services University of the Health Science in Bethesda, Md.
Boden and coauthors also found a high percentage of high school athletes playing with neurologic symptoms from a previous head injury at the time they sustained a catastrophic injury.
Football has more direct catastrophic injuries than any other sport tracked by the National Center for Catastrophic Sports Injury Research (NCCSIR). More than 1.2 million high school athletes played football during the 2001-2002 academic year.
The researchers reviewed 94 incidents of severe football head injuries reported to the NCCSIR during 13 football seasons (Sept. 1989 through June 2002). Catastrophic injury was defined as either direct (resulting from playing the sport) or indirect (resulting from systemic failure secondary to play), and further subclassified those injuries as fatal, nonfatal (injury causing permanent neurological damage), or serious (while severely injured, the player’s injury is immediately relieved, there is no permanent functional disability, and the player recovers completely).
The researchers found that there is approximately one injury per every 150,000 athletes playing, or 7 catastrophic injuries yearly. There were 0.67 injuries per 100,000 players at the high school level and 0.21 injuries per 100,000 for college level football players.
“The incidence of injury is higher at the high school level compared to the college level, which may indicate that the younger brain is more susceptible to a brain injury,” explains Dr. Boden. “Many of the players who had a severe head injury were playing with minor neurological symptoms from a previous head injury such as a concussion.”
From the 94 cases studied, 59 contacts and/or medical records revealed information on prior head injuries. Fifty-nine percent (35/59) of the injured football players had a history of previous head injury of which 71% (25/35) occurred during the same season as the catastrophic event. Nearly 40% (21/54) of the injured athletes were playing with residual neurologic symptoms from prior head injury. The catastrophic injuries resulted in 8 (9%) deaths, 46 (51%) permanent neurologic injuries, and 36 (40%) serious injuries with full recovery.
Dr. Boden suggests that players should be discouraged from using their heads to tackle, since 81% of the injuries were caused by helmet-to-helmet collisions (16/37) and helmet-to-body collisions (14/37).
One of the study’s co-authors, Robert C. Cantu, M.D. of Emerson Hospital, Concord, Mass., has studied catastrophic injuries in many sports. He says that although catastrophic head injuries in football have declined since special regulations went into effect, players are still being returned to the field with symptoms of a prior head injury.
“The single most important piece of advice that I can give is to never let an athlete play football if he has any neurological symptoms whatsoever, says Dr. Boden. Those symptoms may include amnesia, dizziness, headache, irritability, and personality change.
Of the difference in catastrophic head injuries between high school and college players, Boden theorizes: “High school students might take longer to recover from a concussion than college players. Another possible reason for these reported injuries may be that there aren’t as many team physicians covering high school games as college games. Consequently, some high school athletes may not be properly evaluated or receive medical attention.”
“Football is a very macho sport. Athletes are taught to play through pain,” concludes Dr. Boden. “But concussions need to be taken seriously. Many of them are probably being overlooked at the high school level. These injured athletes are allowed to return to play before full recovery, leaving them susceptible to a more significant injury.”
Study finds 'unacceptably high percentage' of high schoolers who sustain catastrophic head injury play with residual effects of prior head injury
The incidence of catastrophic head injuries in football is dramatically higher at the high school level than at the college level, according to a study published in the July issue of The American Journal of Sports Medicine.
Catastrophic head injuries, which include brain bleeding and swelling, are rare and can be devastating. Athletes with major brain injuries may be left with permanent brain damage.
“High school football players have more than three times the risk of a catastrophic head injury than their college peers,” says lead author, Barry P. Boden, M.D., from the Orthopedic Center in Rockville, Md., and adjunct associate professor at the Uniform Services University of the Health Science in Bethesda, Md.
Boden and coauthors also found a high percentage of high school athletes playing with neurologic symptoms from a previous head injury at the time they sustained a catastrophic injury.
Football has more direct catastrophic injuries than any other sport tracked by the National Center for Catastrophic Sports Injury Research (NCCSIR). More than 1.2 million high school athletes played football during the 2001-2002 academic year.
The researchers reviewed 94 incidents of severe football head injuries reported to the NCCSIR during 13 football seasons (Sept. 1989 through June 2002). Catastrophic injury was defined as either direct (resulting from playing the sport) or indirect (resulting from systemic failure secondary to play), and further subclassified those injuries as fatal, nonfatal (injury causing permanent neurological damage), or serious (while severely injured, the player’s injury is immediately relieved, there is no permanent functional disability, and the player recovers completely).
The researchers found that there is approximately one injury per every 150,000 athletes playing, or 7 catastrophic injuries yearly. There were 0.67 injuries per 100,000 players at the high school level and 0.21 injuries per 100,000 for college level football players.
“The incidence of injury is higher at the high school level compared to the college level, which may indicate that the younger brain is more susceptible to a brain injury,” explains Dr. Boden. “Many of the players who had a severe head injury were playing with minor neurological symptoms from a previous head injury such as a concussion.”
From the 94 cases studied, 59 contacts and/or medical records revealed information on prior head injuries. Fifty-nine percent (35/59) of the injured football players had a history of previous head injury of which 71% (25/35) occurred during the same season as the catastrophic event. Nearly 40% (21/54) of the injured athletes were playing with residual neurologic symptoms from prior head injury. The catastrophic injuries resulted in 8 (9%) deaths, 46 (51%) permanent neurologic injuries, and 36 (40%) serious injuries with full recovery.
Dr. Boden suggests that players should be discouraged from using their heads to tackle, since 81% of the injuries were caused by helmet-to-helmet collisions (16/37) and helmet-to-body collisions (14/37).
One of the study’s co-authors, Robert C. Cantu, M.D. of Emerson Hospital, Concord, Mass., has studied catastrophic injuries in many sports. He says that although catastrophic head injuries in football have declined since special regulations went into effect, players are still being returned to the field with symptoms of a prior head injury.
“The single most important piece of advice that I can give is to never let an athlete play football if he has any neurological symptoms whatsoever, says Dr. Boden. Those symptoms may include amnesia, dizziness, headache, irritability, and personality change.
Of the difference in catastrophic head injuries between high school and college players, Boden theorizes: “High school students might take longer to recover from a concussion than college players. Another possible reason for these reported injuries may be that there aren’t as many team physicians covering high school games as college games. Consequently, some high school athletes may not be properly evaluated or receive medical attention.”
“Football is a very macho sport. Athletes are taught to play through pain,” concludes Dr. Boden. “But concussions need to be taken seriously. Many of them are probably being overlooked at the high school level. These injured athletes are allowed to return to play before full recovery, leaving them susceptible to a more significant injury.”
Monday, July 2, 2007
Removal of Unwanted Tattoos
John Klear describes his recent laser treatments this way: “It’s like a really hot Exacto knife slicing through your skin.”
Still, it’s worth it to him to have his tattoos removed. He got them when he was in the Navy, a rite of passage but also a lasting reminder of “the folly of youth,” he says. Later, after deciding he didn’t like the way they looked, he researched tattoo removal on the Internet and decided to go to the University of Michigan Health System for treatment.
His dermatologist, Jeffrey Orringer, M.D., sees many patients who want their tattoos to disappear. Indeed, he says, nearly 20 percent of people with tattoos are thinking of having them removed – and other estimates are even higher. “The most common reason,” he says, “would be to remove a name of someone who is no longer involved in the patient’s life.”
Orringer treats patients with laser technology that allows for a fairly precise removal of the ink without damage to the surrounding skin and, in most cases, without a scar. The technology is far superior to the techniques of the past, which typically resulted in scarring.
Current technology allows the physician to choose certain wavelengths of laser light and shine them on the skin. The wavelength of light from the Q-switched (or quality-switched) laser targets the ink in the skin; the ink heats up when absorbing the laser light, and the balls of ink “pop like popcorn – but on a microscopic basis,” says Orringer, assistant professor of dermatology at the U-M Medical School. The body responds by sending in white blood cells that chew up the altered ink and lighten the tattoo.
For typical, professionally applied tattoos, Orringer orders six to 12 treatment sessions that will clear most tattoos. And it’s not an easy process. “Some patients tell me that having it removed with a laser is somewhat more uncomfortable than acquiring it in the first place,” he notes. The cost also tends to be greater than the price of having the tattoo applied, he says, and can add up to a few thousand dollars for the most complex tattoos. Simpler tattoos cost less than that.
Some tattoos are easier to remove than others. Those that are older, simpler, contain fewer colors are easier to remove, while those located on arms and legs tend to be tougher, Orringer notes.
“I’d say it’s most difficult to remove a tattoo from the ankle area,” he says. “The hands, fingers and other areas at the end of extremities are also more difficult because of a difference in blood flow.”
Counterintuitively, darker colors, such as black, are easier to remove; vivid, bright colors can be more difficult. When tattoo artists mix colors – such as dark blue with white to create sky blue – it can pose difficulties during the removal process. The white ink acts as a shield that reflects much of the laser light, protecting the blue ink and making it more difficult to eradicate with lasers.
For Robert Kelley, 48, the process of having his tattoo removed is a chance for him to teach his son about the potential downside of getting a tattoo. He is pleased that he has the option to have the tattoo removed, but it hasn’t been easy.
“I’ve been able to show my son after my surgeries what the healing process looks like,” says Kelley, who has required more than a dozen laser sessions for the removal of a skull tattoo on his arm, which he got when he was a teenager. “If my son wants a tattoo when he’s older, I’m going to remind him of the process I went through.”
Thinking of having a tattoo removed? 7 things you should know
1. Laser technology can reduce the appearance of tattoos so they are no longer visible. Unlike past treatments, present-day lasers rarely cause scarring or damage to the surrounding skin.
2. It will take more time to remove a tattoo than it took to have it applied. Often, six to 12 sessions are required to erase all of the ink.
3. Areas of the body where it is more difficult to remove a tattoo include ankles, hands and fingers.
4. Older, simpler tattoos that contain few colors are easier to remove.
5. Treatment options include lasers, one of the most common of which is the Q-switched, or quality-switched, laser; surgical excision; and dermabrasion, the “sanding” of the skin.
6. Risks of laser removal of tattoos are similar to those associated with small wounds. The treatment itself can be uncomfortable or even painful as it creates small breaks in the skin. Some crusting or bleeding may occur in the area after treatment. Small risks of scarring, infection and discoloration of the skin also exist.
7. And if you don’t have a tattoo yet – buyer beware. By some estimates, one-fifth of people with tattoos are thinking of having them removed.
For more information, visit these Web sites:
Laser removal of tattoos at the University of Michigan Health System: http://www.med.umich.edu/derm/patient/cdlctreatment.shtml#lasrem
American Academy of Dermatology: http://www.aad.org/public/Publications/pamphlets/tattoo.htm
American Society for Dermatologic Surgery: http://www.asds-net.org/Patients/FactSheets/patients-Fact_Sheet-tattoo_removal.html
Still, it’s worth it to him to have his tattoos removed. He got them when he was in the Navy, a rite of passage but also a lasting reminder of “the folly of youth,” he says. Later, after deciding he didn’t like the way they looked, he researched tattoo removal on the Internet and decided to go to the University of Michigan Health System for treatment.
His dermatologist, Jeffrey Orringer, M.D., sees many patients who want their tattoos to disappear. Indeed, he says, nearly 20 percent of people with tattoos are thinking of having them removed – and other estimates are even higher. “The most common reason,” he says, “would be to remove a name of someone who is no longer involved in the patient’s life.”
Orringer treats patients with laser technology that allows for a fairly precise removal of the ink without damage to the surrounding skin and, in most cases, without a scar. The technology is far superior to the techniques of the past, which typically resulted in scarring.
Current technology allows the physician to choose certain wavelengths of laser light and shine them on the skin. The wavelength of light from the Q-switched (or quality-switched) laser targets the ink in the skin; the ink heats up when absorbing the laser light, and the balls of ink “pop like popcorn – but on a microscopic basis,” says Orringer, assistant professor of dermatology at the U-M Medical School. The body responds by sending in white blood cells that chew up the altered ink and lighten the tattoo.
For typical, professionally applied tattoos, Orringer orders six to 12 treatment sessions that will clear most tattoos. And it’s not an easy process. “Some patients tell me that having it removed with a laser is somewhat more uncomfortable than acquiring it in the first place,” he notes. The cost also tends to be greater than the price of having the tattoo applied, he says, and can add up to a few thousand dollars for the most complex tattoos. Simpler tattoos cost less than that.
Some tattoos are easier to remove than others. Those that are older, simpler, contain fewer colors are easier to remove, while those located on arms and legs tend to be tougher, Orringer notes.
“I’d say it’s most difficult to remove a tattoo from the ankle area,” he says. “The hands, fingers and other areas at the end of extremities are also more difficult because of a difference in blood flow.”
Counterintuitively, darker colors, such as black, are easier to remove; vivid, bright colors can be more difficult. When tattoo artists mix colors – such as dark blue with white to create sky blue – it can pose difficulties during the removal process. The white ink acts as a shield that reflects much of the laser light, protecting the blue ink and making it more difficult to eradicate with lasers.
For Robert Kelley, 48, the process of having his tattoo removed is a chance for him to teach his son about the potential downside of getting a tattoo. He is pleased that he has the option to have the tattoo removed, but it hasn’t been easy.
“I’ve been able to show my son after my surgeries what the healing process looks like,” says Kelley, who has required more than a dozen laser sessions for the removal of a skull tattoo on his arm, which he got when he was a teenager. “If my son wants a tattoo when he’s older, I’m going to remind him of the process I went through.”
Thinking of having a tattoo removed? 7 things you should know
1. Laser technology can reduce the appearance of tattoos so they are no longer visible. Unlike past treatments, present-day lasers rarely cause scarring or damage to the surrounding skin.
2. It will take more time to remove a tattoo than it took to have it applied. Often, six to 12 sessions are required to erase all of the ink.
3. Areas of the body where it is more difficult to remove a tattoo include ankles, hands and fingers.
4. Older, simpler tattoos that contain few colors are easier to remove.
5. Treatment options include lasers, one of the most common of which is the Q-switched, or quality-switched, laser; surgical excision; and dermabrasion, the “sanding” of the skin.
6. Risks of laser removal of tattoos are similar to those associated with small wounds. The treatment itself can be uncomfortable or even painful as it creates small breaks in the skin. Some crusting or bleeding may occur in the area after treatment. Small risks of scarring, infection and discoloration of the skin also exist.
7. And if you don’t have a tattoo yet – buyer beware. By some estimates, one-fifth of people with tattoos are thinking of having them removed.
For more information, visit these Web sites:
Laser removal of tattoos at the University of Michigan Health System: http://www.med.umich.edu/derm/patient/cdlctreatment.shtml#lasrem
American Academy of Dermatology: http://www.aad.org/public/Publications/pamphlets/tattoo.htm
American Society for Dermatologic Surgery: http://www.asds-net.org/Patients/FactSheets/patients-Fact_Sheet-tattoo_removal.html
Cataract Surgery: Safe, Effective & Very Common
Here’s an eye-opening statistic from the July issue of Mayo Clinic Women’s HealthSource: By age 80, more than half of all Americans either have a cataract or have had cataract surgery.
A cataract occurs when the normally clear lens in the eye becomes cloudy, blurring vision and preventing the lens from focusing an image on the retina, the light-sensitive tissue at the back of the eye. While cataracts don’t spread from one eye to another, both eyes are commonly affected.
The only effective treatment for a cataract is surgery to remove the clouded lens. Typically, it’s replaced with an artificial lens known as an intraocular lens. Made from clear plastic, acrylic or silicone, intraocular lenses become a permanent part of the eye.
Cataract surgery is one of the safest and most effective surgical procedures performed in the United States. In years past, it was often recommended that patients wait for a cataract to turn white before having it removed. Today, there are no set recommendations on the best time to remove a cataract. The standard is to have one cataract removed at a time, allowing the eye to heal prior to the second surgery.
Most cataracts don’t disturb vision in the early stages, but as the clouding progresses, a cataract can interfere with everyday life. After successful surgery, patients notice a vision improvement within days. Complete healing generally takes four to six weeks.
Regular eye exams remain the best way to detect cataracts early and monitor their progression. Adults of any age can develop a cataract, but age is the single greatest risk factor. For people over 65, an eye exam at least every other year is recommended.
A cataract occurs when the normally clear lens in the eye becomes cloudy, blurring vision and preventing the lens from focusing an image on the retina, the light-sensitive tissue at the back of the eye. While cataracts don’t spread from one eye to another, both eyes are commonly affected.
The only effective treatment for a cataract is surgery to remove the clouded lens. Typically, it’s replaced with an artificial lens known as an intraocular lens. Made from clear plastic, acrylic or silicone, intraocular lenses become a permanent part of the eye.
Cataract surgery is one of the safest and most effective surgical procedures performed in the United States. In years past, it was often recommended that patients wait for a cataract to turn white before having it removed. Today, there are no set recommendations on the best time to remove a cataract. The standard is to have one cataract removed at a time, allowing the eye to heal prior to the second surgery.
Most cataracts don’t disturb vision in the early stages, but as the clouding progresses, a cataract can interfere with everyday life. After successful surgery, patients notice a vision improvement within days. Complete healing generally takes four to six weeks.
Regular eye exams remain the best way to detect cataracts early and monitor their progression. Adults of any age can develop a cataract, but age is the single greatest risk factor. For people over 65, an eye exam at least every other year is recommended.
Folic Acid and Vitamin B-12: Get Enough of Both
Folate, or its synthetic form, folic acid, is good for brain health. But there’s concern that this brain booster could mask deficiencies in vitamin B-12, which can result in mental decline and other nerve problems. The July issue of Mayo Clinic Health Letter covers why it’s important to have enough of both.
Numerous studies have determined that high levels of folate intake, up to 800 micrograms (mcg) a day, may help ward off cognitive decline, possibly lower the risk of Alzheimer’s disease, and even improve mental sharpness in areas such as memory and mental processing speed.
Folate is also important during pregnancy for the developing fetus, which is why the Food and Drug Administration in 1998 mandated folic acid fortification of grain products sold in the United States.
Vitamin B-12 plays an essential role in red blood cell formation, cell metabolism and nerve function. Where there’s a deficiency, symptoms include persistent tingling in the hands and feet, confusion and forgetfulness.
An estimated 15 percent of older adults are deficient in vitamin B-12. This deficiency can be caused by age-related changes in the digestive tract, which blunt the body’s ability to digest and absorb vitamin B-12 from food. Vegetarians who avoid all animal products and people who have digestive diseases such as celiac disease or Crohn’s disease may also be at increased risk of vitamin B-12 deficiency.
While folic acid offers benefits, there are concerns about how it chemically reacts with vitamin B-12 within the body. It’s suspected that high folic acid intake can correct the anemia — but not the nerve and cognitive deterioration — that would normally occur with vitamin B-12 deficiency. Without the indication of anemia, vitamin B-12 deficiency may not be suspected and neurological deterioration may continue unabated.
More study is needed to fully explore the relationship between folate and vitamin B-12 and how it may affect brain health. Until then, the safest bet is to ensure intake of adequate amounts of both. Most older adults can do this by taking a multivitamin supplement that contains 100 percent of the recommended daily allowance of both folate and vitamin B-12. For folic acid, that’s 400 mcg a day and for vitamin B-12, it’s 2.4 mcg a day.
A healthy diet that includes daily servings of fortified breads, grains or cereals and a wide variety of fresh and natural foods such as fruits, vegetables, beans and nuts can boost daily intake of folate or folic acid to the higher levels that may benefit brain health.
Numerous studies have determined that high levels of folate intake, up to 800 micrograms (mcg) a day, may help ward off cognitive decline, possibly lower the risk of Alzheimer’s disease, and even improve mental sharpness in areas such as memory and mental processing speed.
Folate is also important during pregnancy for the developing fetus, which is why the Food and Drug Administration in 1998 mandated folic acid fortification of grain products sold in the United States.
Vitamin B-12 plays an essential role in red blood cell formation, cell metabolism and nerve function. Where there’s a deficiency, symptoms include persistent tingling in the hands and feet, confusion and forgetfulness.
An estimated 15 percent of older adults are deficient in vitamin B-12. This deficiency can be caused by age-related changes in the digestive tract, which blunt the body’s ability to digest and absorb vitamin B-12 from food. Vegetarians who avoid all animal products and people who have digestive diseases such as celiac disease or Crohn’s disease may also be at increased risk of vitamin B-12 deficiency.
While folic acid offers benefits, there are concerns about how it chemically reacts with vitamin B-12 within the body. It’s suspected that high folic acid intake can correct the anemia — but not the nerve and cognitive deterioration — that would normally occur with vitamin B-12 deficiency. Without the indication of anemia, vitamin B-12 deficiency may not be suspected and neurological deterioration may continue unabated.
More study is needed to fully explore the relationship between folate and vitamin B-12 and how it may affect brain health. Until then, the safest bet is to ensure intake of adequate amounts of both. Most older adults can do this by taking a multivitamin supplement that contains 100 percent of the recommended daily allowance of both folate and vitamin B-12. For folic acid, that’s 400 mcg a day and for vitamin B-12, it’s 2.4 mcg a day.
A healthy diet that includes daily servings of fortified breads, grains or cereals and a wide variety of fresh and natural foods such as fruits, vegetables, beans and nuts can boost daily intake of folate or folic acid to the higher levels that may benefit brain health.
Staying Mentally Sharp Takes Brain Work
Research is increasingly showing that aging doesn’t automatically result in a steady erosion of brain cells. Rather, older adults who work their brains can develop new connections between brain cells.
A brain workout — using the mind in a wide variety of new and challenging ways — can activate cells throughout the brain. The July issue of Mayo Clinic Health Letter offers these suggestions to stimulate the mind:
Working the left brain — Language, number and reasoning activities are often considered left-brain activities. Reading, writing, learning a new language, completing number or work games, balancing a checkbook without a calculator and fixing broken objects are left-brain activities.
Working the right brain — Music, art and using the imagination are considered right-brain activities. Options to stimulate this side include reviving a musical talent, singing in a choir, knitting, quilting or taking art classes.
Breaking a routine — Long-familiar daily routines can become so ingrained that little thought is required. When one breaks up routines, meets a new person, learns a skill or takes a different route to the store, the brain is engaged.
Remembering or memorization — Brain-building ideas include memorizing phone numbers, the words to a poem or people’s names.
Trying meditation — Studies have shown that meditation activates the parts of the brain associated with happiness and contentment and reduces stress and anxiety. This effect can occur even in those new to meditation, and grows more robust with practice.
Engaging in social activity — Engaging in conversation or activity with a wide variety of people — family, friends or strangers — can be one of the most complex and varied tasks that the mind undertakes. Social engagement has been linked in many studies to the reduction of mental decline.
A brain workout — using the mind in a wide variety of new and challenging ways — can activate cells throughout the brain. The July issue of Mayo Clinic Health Letter offers these suggestions to stimulate the mind:
Working the left brain — Language, number and reasoning activities are often considered left-brain activities. Reading, writing, learning a new language, completing number or work games, balancing a checkbook without a calculator and fixing broken objects are left-brain activities.
Working the right brain — Music, art and using the imagination are considered right-brain activities. Options to stimulate this side include reviving a musical talent, singing in a choir, knitting, quilting or taking art classes.
Breaking a routine — Long-familiar daily routines can become so ingrained that little thought is required. When one breaks up routines, meets a new person, learns a skill or takes a different route to the store, the brain is engaged.
Remembering or memorization — Brain-building ideas include memorizing phone numbers, the words to a poem or people’s names.
Trying meditation — Studies have shown that meditation activates the parts of the brain associated with happiness and contentment and reduces stress and anxiety. This effect can occur even in those new to meditation, and grows more robust with practice.
Engaging in social activity — Engaging in conversation or activity with a wide variety of people — family, friends or strangers — can be one of the most complex and varied tasks that the mind undertakes. Social engagement has been linked in many studies to the reduction of mental decline.
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