Health Research Report
139th Issue Date 05 OCT 2012
Compiled By Ralph Turchiano
Editors Top Five:
- Melatonin and exercise work against Alzheimer’s in mice
- Eating cherries lowers risk of gout attacks by 35 percent
- Beta-blocker use not associated with lower risk of cardiovascular events
- Zinc deficiency mechanism linked to aging, multiple diseases
- Making headway on beta-blockers and sleep
In this Issue:
1. Bees decrease food intake, live longer when given compound found in red wine
2. Doctors’ ‘gut feeling’ should not be ignored
3. EXERCISE DOES A BODY – AND A MIND – GOOD
4. WSU STUDY FINDS DIOXIN CAUSES DISEASE AND REPRODUCTIVE PROBLEMS ACROSS GENERATIONS
5. Melatonin and exercise work against Alzheimer’s in mice
6. Antibiotics could replace surgery for appendicitis
7. NEW WAY OF FIGHTING HIGH CHOLESTEROL UPENDS ASSUMPTIONS
8. OVER 65S AT INCREASED RISK OF DEVELOPING DEMENTIA WITH BENZODIAZEPINE
9. Making headway on beta-blockers and sleep
10. Eating cherries lowers risk of gout attacks by 35 percent
11. Misconduct, not error, accounts for most scientific paper retractions
12. Zinc deficiency mechanism linked to aging, multiple diseases
13. RELEASE: Fluoxetine increases aggressive behavior, affects brain development among adolescent hamsters
14. Omega-3 Supplements May Slow A Biological Effect of Aging
15. Beta-blocker use not associated with lower risk of cardiovascular events
16. Low levels of vitamin D are associated with mortality in older adults
17. ‘Superweeds’ linked to rising herbicide use in GM crops
18. Study: An Apple a Day Lowers Level of Blood Chemical Linked to Hardening of the Arteries
19. New study links caffeinated coffee to vision loss
20. New study sheds light on cancer-protective properties of milk
21. BPA linked to thyroid hormone changes in pregnant women, newborns
22. Chewing ability linked to reduced dementia risk
23. Tree Nut Research May Unexpectedly Lead to Medical Advances / Thyme
Bees decrease food intake, live longer when given compound found in red wine
ASU researchers have confirmed that not only does resveratrol, a compound found in red wine, extend the lifespan of honey bees by 33 to 38 percent, it also changes the decisions that bees make about food by triggering a “moderation effect” when they eat.
Photo by: Brenda Rascón
The idea that drinking red wine may provide health benefits – or possibly even extend your life – is an appealing thought for many people. Now, there may be added attraction. Researchers have found that when given resveratrol, a compound found in red wine, bees consume less food.
Previous scientific studies on resveratrol show that it lengthens the lifespan of diverse organisms ranging from unicellular yeast to fruit flies and mice. Since bees are social animals like humans, a team of scientists from Arizona State University, the Norwegian University of Life Sciences, and Harvard Medical School, decided to test the effects of the chemical on the honey bee.
In a series of experiments published in the journal Aging, the scientists tested the effects of resveratrol on the lifespan, learning ability, and food perception in honey bees.
Their research has confirmed that not only does this compound extend the lifespan of honey bees by 33 to 38 percent, it also changes the decisions that bees make about food by triggering a “moderation effect” when they eat.
“For the first time, we conducted several tests on the effects of resveratrol by using the honey bee as a model,” said Brenda Rascón, an ASU alumnus and doctoral student with Gro Amdam, an associate professor in ASU’s School of Life Sciences and the Norwegian University of Life Sciences. “We were able to confirm that under normal living conditions, resveratrol lengthened lifespan in honey bees.”
Since resveratrol is an antioxidant, researchers also questioned whether it would be capable of diminishing the damaging effects of “free radicals” – often released during stressful conditions. Free radicals are believed to cause damage to cells, and have an effect on how we age. Resveratrol did not, however, prove to extend lives of bees living under stressful conditions.
Yet, since the bees tested with the compound were living longer, researchers asked the next question: What’s happening that is causing them to live longer?
“Because what we eat is such an important contributor to our physical health, we looked at the bees’ sensitivity to sugar and their willingness to consume it,” said Amdam. “Bees typically gorge on sugar and while it’s the best thing for them, we know that eating too much is not necessarily a good thing.”
Interestingly, Amdam, Rascón, and their research team discovered that bees given the compound were less sensitive to sugar. By using different sugar solutions – some very diluted and some with stronger concentrations – they found that bees receiving resveratrol were not as interested in eating the sugar solutions unless the sugar was highly concentrated. The bees basically changed their perception about food.
In a final experiment, they measured how much food the bees would consume if given the opportunity to eat as much sugar water as they possibly could.
“Surprisingly, the bees that received the drug decreased their food intake,” said Rascón. “The bees were allowed to eat as much as they pleased and were certainly not starving – they simply would not gorge on the food that we know they like. It’s possible resveratrol may be working by some mechanism that is related to caloric restriction – a dietary regimen long known to extend lifespan in diverse organisms.”
The Research Council of Norway and the PEW Charitable Trust funded this study.
ASU School of Life Sciences is an academic unit of the College of Liberal Arts and Sciences.
Doctors’ ‘gut feeling’ should not be ignored
Research: Clinicians’ gut feeling about serious infections in children: Observational study
Doctors who experience a gut feeling about serious illness when treating a child in primary care should take action upon this feeling and not ignore it, a study published today on bmj.com suggests.
Serious infection can easily be missed in young children and making a diagnosis has been described as “like finding a needle in a haystack”. A clinician’s intuitive feeling that something is wrong, even after examination that suggests otherwise, appears to have diagnostic value, even greater diagnostic value than most symptoms and signs. Studies have suggested it should be seen as highly important in its own right but there is lack of understanding about whether it can be seen as useful.
Researchers from Oxford and Belgium therefore carried out an observational study on 3890 children between the ages of 0-16 years who presented in primary care in Flanders, Belgium in 2004. They wanted to see what added value gut feeling provides to a diagnosis. Factors recorded included the doctor’s overall impression and whether gut feeling suggested something more serious was wrong. Gut feeling was defined as “intuitive feeling that something was wrong even if the clinician was unsure why”.
Out of the 3369 children assessed as having a non-severe illness at the time of consultation, six (0.2%) were later admitted to hospital with a serious infection. Results show that acting on gut feeling had the potential to prevent two of the six cases being missed at the cost of 44 false alarms, but that these were not “unmanageable”. The probability of a serious infection decreased from 0.2% to 0.1% when gut feeling was absent.
In fact, 21 out of the 3890 children were eventually admitted to hospital with a serious infection and nine were not referred at first contact. However, in four of the nine children, the doctor had a gut feeling that something serious was wrong.
The feature most strongly associated with gut feeling was a history of convulsions and the child’s overall appearance and breathing.The authors also found that gut feeling is strongly influenced by parental concern that the illness is different. Finally, less experienced clinicians reported it more frequently than their more senior counterparts. However, the diagnostic power of gut feeling was no better in experienced than non-experienced clinicians.
The authors recommend that medical teaching should make clear that an “inexplicable gut feeling is an important diagnostic sign and a very good reason for seeking the opinion of someone with more paediatric expertise or performing additional testing”. They say that gut feeling should make three things mandatory: conducting a full and careful examination; seeking advice from a more experienced clinician and providing the parent with safety netting advice. They conclude that clinicians should not ignore gut feeling and use it in decision making.
Exercise Does a Body – and a Mind – Good
We’ve heard it time and time again: exercise is good for us. And it’s not just good for physical health – research shows that daily physical activity can also boost our mental health. But what actually accounts for the association between exercise and mental health?
A new article in Clinical Psychological Science, a journal of the Association for Psychological Science, explores whether certain psychosocial factors may help to explain the benefits of daily physical activity for adolescents’ mental health.
Karin Monshouwer of the Trimbos Institute in the Netherlands and colleagues at Trimbos and VU University Medical Center specifically wanted to examine two existing explanations for the link between exercise and mental health. The self-image hypothesis suggests that physical activity has positive effects on body weight and body structure, leading to positive feedback from peers and improved self-image, and ultimately improving mental health. The social interaction hypothesis, on the other hand, holds that it’s the social aspects of physical activity – such as social relationships and mutual support among team members – that contribute to the positive effects of exercise on mental health.
Monshouwer and her colleagues surveyed over 7000 Dutch students, ages 11 to 16. The adolescents completed validated surveys aimed at assessing their physical activity, mental health problems, body weight perception, and participation in organized sports. The researchers also gathered data on the adolescents’ age, gender, and socioeconomic status; whether they lived at home with their parents; and whether they lived in an urban area.
The researchers found that adolescents who were physically inactive or who perceived their bodies as either “too fat” or “too thin” were at greater risk for both internalizing problems (e.g., depression, anxiety) and externalizing problems (e.g., aggression, substance abuse). Adolescents who participated in organized sports, on the other hand, were at lower risk for mental health problems.
Confirming both the self-image hypothesis and the social interaction hypothesis, adolescents’ body weight perception (i.e., “too heavy,” “good,” or “too thin”) and sports club membership each partially accounted for the relationship between physical activity and mental health, even after taking adolescents’ backgrounds into account.
These results suggest that certain psychosocial factors – body image and social interaction – may help to explain at least part of the connection between physical activity and mental health. The researchers acknowledge, however, that other factors, such as the physiological effects of exercise, are probably also at work.
“We think that these findings are important for policymakers and anyone who works in healthcare or prevention. Our findings indicate that physical activity may be one effective tool for the prevention of mental health problems in adolescence,” says Monshouwer.
Monshouwer and her colleagues hope that future studies will be able to examine similar questions while following participants over time. Such longitudinal studies could help researchers to understand how physical activity type and context might influence the relationship between exercise and mental health.
Clinical Psychological Science — a new journal from APS — publishes advances in clinical science and provides a venue for cutting-edge research across a wide range of conceptual views, approaches, and topics. The journal encompasses many core domains that have defined clinical psychology, but also boundary-crossing advances that integrate and make contact with diverse disciplines and that may not easily be found in traditional clinical psychology journals. Among the key topics are research on the underlying mechanisms and etiologies of psychological health and dysfunction; basic and applied work on the diagnosis, assessment, treatment, and prevention of mental illness; service delivery; and promotion of well-being
WSU study finds dioxin causes disease and reproductive problems across generations
Effects could extend to ‘great-grandchildren’
PULLMAN, Wash.—Since the 1960s, when the defoliant Agent Orange was widely used in Vietnam, military, industry and environmental groups have debated the toxicity of its main ingredient, the chemical dioxin, and how it should be regulated.
But even if all the dioxin were eliminated from the planet, Washington State University researchers say its legacy will live on in the way it turns genes on and off in the descendants of people exposed over the past half century.
Writing in the journal PLoS ONE, biologist Michael Skinner and members of his lab say dioxin administered to pregnant rats resulted in a variety of reproductive problems and disease in subsequent generations. The first generation of rats had prostate disease, polycystic ovarian disease and fewer ovarian follicles, the structures that contain eggs. To the surprise of Skinner and his colleagues, the third generation had even more dramatic incidences of ovarian disease and, in males, kidney disease.
“Therefore, it is not just the individuals exposed, but potentially the great-grandchildren that may experience increased adult-onset disease susceptibility,” says Skinner.
Skinner is a professor of reproductive biology and environmental epigenetics – the process in which environmental factors affect how genes are turned on and off in the offspring of an exposed animal, even though its DNA sequences remain unchanged. In this year alone, Skinner and colleagues have published studies finding epigenetic diseases promoted by jet fuel and other hydrocarbon mixtures, plastics, pesticides and fungicides, as well as dioxin.
The field of epigenetics opens new ground in the study of how diseases and reproductive problems develop. While toxicologists generally focus on animals exposed to a compound, work in Skinner’s lab further demonstrates that diseases can also stem from older, ancestral exposures that are then mediated through epigenetic changes in sperm.
Melatonin and exercise work against Alzheimer’s in mice
Different anti-aging treatments work together and add years of life
The combination of two neuroprotective therapies, voluntary physical exercise, and the daily intake of melatonin has been shown to have a synergistic effect against brain deterioration in rodents with three different mutations of Alzheimer’s disease.
A study carried out by a group of researchers from the Barcelona Biomedical Research Institute (IIBB), in collaboration with the University of Granada and the Autonomous University of Barcelona, shows the combined effect of neuroprotective therapies against Alzheimer’s in mice.
Daily voluntary exercise and daily intake of melatonin, both of which are known for the effects they have in regulating circadian rhythm, show a synergistic effect against brain deterioration in the 3xTg-AD mouse, which has three mutations of Alzheimer’s disease.
“For years we have known that the combination of different anti-aging therapies such as physical exercise, a Mediterranean diet, and not smoking adds years to one’s life,” Coral Sanfeliu, from the IIBB, explains to SINC. “Now it seems that melatonin, the sleep hormone, also has important anti-aging effects”.
The experts analysed the combined effect of sport and melatonin in 3xTg-AD mice which were experiencing an initial phase of Alzheimer’s and presented learning difficulties and changes in behaviour such as anxiety and apathy.
The mice were divided into one control group and three other groups which would undergo different treatments: exercise –unrestricted use of a running wheel–, melatonin –a dose equivalent to 10 mg per kg of body weight–, and a combination of melatonin and voluntary physical exercise. In addition, a reference group of mice were included which presented no mutations of the disease.
“After six months, the state of the mice undergoing treatment was closer to that of the mice with no mutations than to their own initial pathological state. From this we can say that the disease has significantly regressed,” Sanfeliu states.
The results, which were published in the journal Neurobiology of Aging, show a general improvement in behaviour, learning, and memory with the three treatments.
These procedures also protected the brain tissue from oxidative stress and provided good levels of protection from excesses of amyloid beta peptide and hyperphosphorylated TAU protein caused by the mutations. In the case of the mitochondria, the combined effect resulted in an increase in the analysed indicators of improved performance which were not observed independently.
Treatment not easily transferable to humans
“Transferring treatments which are effective in animals to human patients is not always consistent, given that in humans the disease develops over several years, so that when memory loss begins to surface, the brain is already very deteriorated,” the IIBB expert points out.
However, several clinical studies have found signs of physical and mental benefits in sufferers of Alzheimer’s resulting from both treatments. The authors maintain that, until an effective pharmacological treatment is found, adopting healthy living habits is essential for reducing the risk of the disease appearing, as well as reducing the severity of its effects.
The melatonin debate
The use of melatonin, a hormone synthesized from the neurotransmitter serotonin, has positive effects which can be used for treating humans. With the approval of melatonin as a medication in the European Union in 2007, clinical testing on this molecule has been increasing. It has advocates as well as detractors, and the scientific evidence has not yet been able to unite the differing views.
According to the Natural Medicines Comprehensive Database, melatonin is probably effective in sleeping disorders in children with autism and mental retardation and in blind people; and possibly effective in case of jet-lag, sunburns and preoperative anxiety.
“However, other studies which use melatonin as medication show its high level of effectiveness,” Darío Acuña-Castroviejo explains to SINC. He has been studying melatonin for several years at the Health Sciences Technology Park of the University of Granada.
The expert points out that international consensus already exists, promoted by the British Association for Psychopharmacology –also published in the Journal of Psychopharmacology in 2010–, which has melatonin as the first choice treatment for insomnia in patients above the age of 55. This consensus is now being transferred to cases of insomnia in children.
Its use in treating neurodegenerative diseases is acquiring increasing scientific support in lateral amyotrophic sclerosis, in Alzheimer’s, and Duchenne muscular dystrophy.
“Even though many more studies and clinical tests are still required to assess the doses of melatonin which will be effective for a wide range of diseases, the antioxidant and anti-inflammatory properties of melatonin mean that its use is highly recommended for diseases which feature oxidative stress and inflammation,” Acuña-Castroviejo states.
This is the case for diseases such as epilepsy, chronic fatigue, fibromyalgia, and even the aging process itself, where data is available pointing to the benefits of melatonin, though said data is not definitive.
Antibiotics could replace surgery for appendicitis
Although the standard approach to acute appendicitis is to remove the appendix, a study at the Sahlgrenska Academy, University of Gothenburg, Sweden, reveals that treatment with antibiotics can be just as effective in many cases.
In her thesis, Jeanette Hansson discusses two major clinical studies of adult patients with acute appendicitis. In the first study she compares surgery with antibiotic therapy, while in the second patients with appendicitis were treated with antibiotics as first-line therapy.
Carried out at Sahlgrenska University Hospital and Kungälv Hospital, the studies showed that treatment with antibiotics was just as effective as surgery for the majority of patients. “Some patients are so ill that the operation is absolutely necessary, but 80 percent of those who can be treated with antibiotics recover and return to full health,” says Jeanette Hansson.
The thesis also shows that patients who are treated with antibiotics are at risk of fewer complications than those who undergo surgery.
The risk of recurrence within 12 months of treatment with antibiotics is around 10-15 percent. Jeanette Hansson and her colleagues hope to be able to document the risk of recurrence over the long term and also to study whether recurrences can also be treated with antibiotics. Even though increased resistance to antibiotics could also affect the treatment, the conclusion is that antibiotics are a viable alternative to surgery in adult patients as things stand, provided that the patient accepts the risk of recurrence.
“It’s important to note that our studies show that patients who need surgery because of recurrences, or because the antibiotics haven’t worked, are not at risk of any additional complications relative to those operated on in the first place,” says Jeanette Hansson
New way of fighting high cholesterol upends assumptions
Atherosclerosis – the hardening of arteries that is a primary cause of cardiovascular disease and death – has long been presumed to be the fateful consequence of complicated interactions between overabundant cholesterol and resulting inflammation in the heart and blood vessels.
However, researchers at the University of California, San Diego School of Medicine, with colleagues at institutions across the country, say the relationship is not exactly what it appears, and that a precursor to cholesterol actually suppresses inflammatory response genes. This precursor molecule could provide a new target for drugs designed to treat atherosclerosis, which kills tens of thousands of Americans annually.
The findings are published in the September 28, 2012 issue of Cell.
Lurking within our arterial walls are immune system cells called macrophages (Greek for “big eater”) whose essential function is to consume other cells or matter identified as foreign or dangerous. “When they do that, it means they consume the other cell’s store of cholesterol,” said Christopher Glass, MD, PhD, a professor in the Departments of Medicine and Cellular and Molecular Medicine and senior author of the Cell study. “As a result, they’ve developed very effective ways to metabolize the excess cholesterol and get rid of it.”
But some macrophages fail to properly dispose of the excess cholesterol, allowing it to instead accumulate inside them as foamy lipid (fat) droplets, which gives the cells their particular name: macrophage foam cells.
These foam macrophages produce molecules that summon other immune cells and release molecules, signaling certain genes to launch an inflammatory response. Glass said conventional wisdom has long assumed atherosclerotic lesions – clumps of fat-laden foam cells massed within arterial walls – were the unhealthy consequence of an escalating association between unregulated cholesterol accumulation and inflammation.
Glass and colleagues wanted to know exactly how cholesterol accumulation led to inflammation, and why the macrophages failed to do their job. Using specialized mouse models that produced abundant macrophage foam cells, they made two unexpected discoveries that upend previous assumptions about how lesions form and how atherosclerosis might be more effectively treated.
“The first is that foam cell formation suppressed activation of genes that promote inflammation. That’s exactly the opposite of what we thought happened,” said Glass. “Second, we identified a molecule that helps normal macrophages manage cholesterol balance. When it’s in abundance, it turns on cellular pathways to get rid of cholesterol and turns off pathways for producing more cholesterol.”
That molecule is desmosterol – the final precursor in the production of cholesterol, which cells make and use as a structural component of their membranes. In atherosclerotic lesions, Glass said the normal function of desmosterol appears to be “crippled.”
“That’s the next thing to study; why that happens,” Glass said, hypothesizing that the cause may be linked to overwhelming, pro-inflammatory signals coming from proteins called Toll-like receptors on macrophages and other cells that, like macrophages, are critical elements of the immune system.
The identification of desmosterol’s ability to reduce macrophage cholesterol presents researchers and drug developers with a potential new target for reducing the risk of atherosclerosis.
Glass noted that a synthetic molecule similar to desmosterol already exists, offering an immediate test-case for new studies. In addition, scientists in the 1950s developed a drug called triparanol that inhibited cholesterol production, effectively boosting desmosterol levels. The drug was sold as a heart disease medication, but later discovered to cause severe side effects, including blindness from an unusual form of cataracts. It was pulled from the market and abandoned.
“We’ve learned a lot in 50 years,” said Glass. “Maybe there’s a way now to create a new drug that mimics the cholesterol inhibition without the side effects.”
Over 65s at increased risk of developing dementia with benzodiazepine
Research: Benzodiazepine use and risk of dementia: Prospective population based study
Research: Benzodiazepine use and risk of dementia: prospective population based study
Patients over the age of 65 who begin taking benzodiazepine (a popular drug used to treat anxiety and insomnia) are at an approximately 50% increased risk of developing dementia within 15 years compared to never-users, a study published today on bmj.com suggests.
The authors say that “considering the extent to which benzodiazepines are prescribed and the number of potential adverse effects indiscriminate widespread use should be cautioned against”.
Benzodiazepine is a widely prescribed drug for the over 65s in many countries: 30% of this age group in France, 20% in Canada and Spain, 15% in Australia. Although less widespread in the UK and US it is still very widely used and many individuals take this drug for years despite guidelines suggesting it should be limited to a few weeks. Previous studies have found an increased risk of dementia, but others have been non-conclusive.
Researchers from France therefore carried out a study on 1063 men and women (average age 78) in France who were all free of dementia at the start. The study started in 1987 and follow-up was 20 years. The researchers used the first 5 years to identifying the factors leading to benzodiazepine initiation and evaluated then the association between new use of this drug and the development of dementia. They also assessed the association between further benzodiazepine initiation during the follow-up period and risk of subsequent dementia. Rates were adjusted for many factors potentially affecting dementia, such as age, gender, educational level, marital status, wine consumption, diabetes, high blood pressure, cognitive decline, and depressive symptoms.
95 out of the 1063 patients started taking benzodiazepine during the study. 253 (23.8%) cases of dementia were confirmed, 30 in benzodiazepine users and 223 in non-users. New initiation of the drug was associated with shorter dementia-free survival.
In absolute numbers, the chance of dementia occurring was 4.8 per 100 person years in the exposed group compared to 3.2 per 100 person years in the non-exposed group. A “person year” is a statistical measure representing one person at risk of development of a disease during a period of one year.
The authors say that although benzodiazepine remains useful for treating anxiety and insomnia, there is increasing evidence that its use may induce adverse outcomes in the elderly such as serious falls and fall-related fractures and this study may add dementia to the list. They say that their data add to the accumulating evidence that the use of benzodiazepines is associated with increased risk of dementia and, if true, that this “would constitute a substantial public health concern”. Therefore, taken the evidence of potential adverse effects into account, physicians should assess expected benefits, limit prescriptions to a few weeks, and uncontrolled use should be cautioned against. They conclude that further research should “explore whether use of benzodiazepine in those under 65 is also associated with increased risk of dementia and that mechanisms need to be explored explaining the association
Making headway on beta-blockers and sleep
Researchers at Brigham and Women’s Hospital have found that melatonin supplementation significantly improved sleep in hypertensive patients taking beta-blockers
Boston, MA—Over 20 million people in the United States take beta-blockers, a medication commonly prescribed for cardiovascular issues, anxiety, hypertension and more. Many of these same people also have trouble sleeping, a side effect possibly related to the fact that these medications suppress night-time melatonin production. Researchers at Brigham and Women’s Hospital (BWH) have found that melatonin supplementation significantly improved sleep in hypertensive patients taking beta-blockers.
The study will be electronically published on September 28, 2012 and will be published in the October print issue of SLEEP.
“Beta-blockers have long been associated with sleep disturbances, yet until now, there have been no clinical studies that tested whether melatonin supplementation can improve sleep in these patients,” explained Frank Scheer, PhD, MSc, an associate neuroscientist at BWH, and principal investigator on this study. “We found that melatonin supplements significantly improved sleep.”
The research team analyzed 16 hypertensive patients who regularly took beta-blockers as treatment for their hypertension. The study participants were given either a melatonin supplement or placebo to take each night before bed. To avoid bias, neither the participants nor the researchers knew which pill they were taking. During the three week study, the participants spent two separate four-day visits in lab. While in the lab, the researchers assessed the participants’ sleep patterns and found a 37-minute increase in the amount of sleep in the participants who received the melatonin supplement compared to those who received placebo. They also found an eight percent improvement of sleep efficiency and a 41 minute increase in the time spent in Stage 2 sleep, without a decrease in slow wave sleep or REM sleep.
“Over the course of three weeks, none of the study participants taking the melatonin showed any of the adverse effects that are often observed with other, classic sleep aids. There were also no signs of ‘rebound insomnia’ after the participants stopped taking the drug,” explained Scheer, who is also an assistant professor of Medicine at Harvard Medical School. “In fact, melatonin had a positive carry-over effect on sleep even after the participants had stopped taking the drug.”
The researchers caution that while this data is promising for hypertensive patients taking beta-blockers, more research is needed to determine whether patients taking beta-blockers for causes other thanhypertension could also benefit from melatonin supplementation.
Eating cherries lowers risk of gout attacks by 35 percent
A new study found that patients with gout who consumed cherries over a two-day period showed a 35% lower risk of gout attacks compared to those who did not eat the fruit. Findings from this case-crossover study published in Arthritis & Rheumatism, a journal of the American College of Rheumatology (ACR), also suggest that risk of gout flares was 75% lower when cherry intake was combined with the uric-acid reducing drug, allopurinol, than in periods without exposure to cherries or treatment.
Previous research reports that 8.3 million adults in the U.S. suffer with gout, an inflammatory arthritis triggered by a crystallization of uric acid within the joints that causes excruciating pain and swelling. While there are many treatment options available, gout patients continue to be burdened by recurrent gout attacks, prompting patients and investigators to seek other preventive options such as cherries. Prior studies suggest that cherry products have urate-lowering effects and anti-inflammatory properties, and thus may have the potential to reduce gout pain. However, no study has yet to assess whether cherry consumption could lower risk of gout attacks.
For the present study, lead author Dr. Yuqing Zhang, Professor of Medicine and Public Health at Boston University and colleagues recruited 633 gout patients who were followed online for one year. Participants were asked about the date of gout onset, symptoms, medications and risk factors, including cherry and cherry extract intake in the two days prior to the gout attack. A cherry serving was one half cup or 10 to 12 cherries.
Participants had a mean age of 54 years, with 88% being white and 78% of subjects were male. Of those subjects with some form of cherry intake, 35% ate fresh cherries, 2% ingested cherry extract, and 5% consumed both fresh cherry fruit and cherry extract. Researchers documented 1,247 gout attacks during the one-year follow-up period, with 92% occurring in the joint at the base of the big toe.
“Our findings indicate that consuming cherries or cherry extract lowers the risk of gout attack,” said Dr. Zhang. “The gout flare risk continued to decrease with increasing cherry consumption, up to three servings over two days.” The authors found that further cherry intake did not provide any additional benefit. However, the protective effect of cherry intake persisted after taking into account patients’ sex, body mass (obesity), purine intake, along with use of alcohol, diuretics and anti-gout medications.
In their editorial, also published in Arthritis & Rheumatism, Dr. Allan Gelber from Johns Hopkins University School of Medicine in Baltimore, Md. and Dr. Daniel Solomon from Brigham and Women’s Hospital and Harvard University Medical School in Boston, Mass. highlight the importance of the study by Zhang et al. as it focuses on dietary intake and risk of recurrent gout attacks. While the current findings are promising, Gelber and Solomon “would not advise that patients who suffer from gout attacks abandon standard therapies.” Both the editorial and study authors concur that randomized clinical trials are necessary to confirm that consumption of cherry products could prevent gout attacks
hypertension could also benefit from melatonin supplementation.
Misconduct, not error, accounts for most scientific paper retractions
New study finds 10-fold increase in fraud-related retractions
October 1, 2012 — (Bronx, NY) — In sharp contrast to previous studies suggesting that errors account for the majority of retracted scientific papers, a new analysis—the most comprehensive of its kind—has found that misconduct is responsible for two-thirds of all retractions. In the paper, misconduct included fraud or suspected fraud, duplicate publication and plagiarism. The paper’s findings show as a percentage of all scientific articles published, retractions for fraud or suspected fraud have increased 10-fold since 1975. The study, from a collaboration between three scientists including one at Albert Einstein College of Medicine of Yeshiva University, published online today in the Proceedings of the National Academy of Sciences (PNAS).
“Biomedical research has become a winner-take-all game—one with perverse incentives that entice scientists to cut corners and, in some instances, falsify data or commit other acts of misconduct,” said senior author Arturo Casadevall, M.D., Ph.D. , the Leo and Julia Forchheimer Chair and professor of microbiology & immunology and professor of medicine at Einstein. Dr. Casadevall is also editor-in-chief of the journal mBio.
The study reviewed 2,047 papers retracted from the biomedical literature through May 2012. To determine the reasons for the retractions, the researchers consulted several secondary sources, such as the National Institutes of Health (NIH) Office of Research Integrity and Retractionwatch.com, which investigate scientific misconduct.
The researchers found that about 21 percent of the retractions were attributable to error, while 67 percent were due to misconduct, including fraud or suspected fraud (43 percent), duplicate publication (14 percent), and plagiarism (10 percent). Miscellaneous or unknown reasons accounted for the remaining 12 percent.
“What’s troubling is that the more skillful the fraud, the less likely that it will be discovered, so there likely are more fraudulent papers out there that haven’t yet been detected and retracted,” said Dr. Casadevall.
Earlier studies that underestimated the extent of scientific misconduct relied solely on the journals’ retraction notices, which are written by the papers’ authors, according to Dr. Casadevall. “Many of those notices are wrong,” he said. “Authors commonly write, ‘We regret we have to retract our paper because the work is not reproducible,’ which is not exactly a lie. The work indeed was not reproducible — because it was fraudulent. Researchers try to protect their labs and their reputations, and these retractions are written in such a way that you often don’t know what really happened.”
The PNAS study also found that journals with higher impact factors (a measure of a publication’s influence in scientific circles) had especially high rates of retractions. Dr. Casadevall attributes the growing number of retracted papers to the prevailing culture in science, which disproportionately rewards scientists for publishing large numbers of papers and getting them published in prestigious journals.
“Particularly if you get your papers accepted in certain journals, you’re much more likely to get recognition, grants, prizes and better jobs or promotions,” he said. “Scientists are human, and some of them will succumb to this pressure, especially when there’s so much competition for funding. Perhaps our most telling finding is what happened after 2005, which is when the number of retractions began to skyrocket. That’s exactly when NIH funding began to get very tight.”
In a recent article in Infection and Immunity, Dr. Casadevall proposed various solutions to the problem of scientific misconduct, including:
- more emphasis on the quality of publications rather than quantity
- less emphasis on impact measures when rating journals
- fostering a cooperative and collaborative culture in the research community
- developing more stable and sustainable sources of research funding.
- creating more flexible career pathways to prevent the ongoing loss of capable scientists due to inadequate funding
The retraction study’s findings weren’t all gloom and doom. “There is a very optimistic piece of data in the paper,” noted Dr. Casadevall: 43 percent of all retractions came from just 38 of the thousands of labs worldwide. “So while we’re not looking at a systemic disease, so to speak, in the scientific community, our findings do indicate a significant problem that needs to be addressed.”
The paper is titled, “Misconduct accounts for the majority of retracted scientific publications.” Additional authors are Ferric Fang, M.D. (University of Washington School of Medicine, Seattle, WA) and R. Grant Steen, Ph.D. (Medical Communications Consultants, Chapel Hill, NC).
The authors declare no conflicts of interest.
Zinc deficiency mechanism linked to aging, multiple diseases
CORVALLIS, Ore. – A new study has outlined for the first time a biological mechanism by which zinc deficiency can develop with age, leading to a decline of the immune system and increased inflammation associated with many health problems, including cancer, heart disease, autoimmune disease and diabetes.
The research was done by scientists in the Linus Pauling Institute at Oregon State University and the OSU College of Public Health and Human Sciences. It suggests that it’s especially important for elderly people to get adequate dietary intake of zinc, since they may need more of it at this life stage when their ability to absorb it is declining.
About 40 percent of elderly Americans and as many as two billion people around the world have diets that are deficient in this important, but often underappreciated micronutrient, experts say.
The study was published in the Journal of Nutritional Biochemistry, based on findings with laboratory animals. It found that zinc transporters were significantly dysregulated in old animals. They showed signs of zinc deficiency and had an enhanced inflammatory response even though their diet supposedly contained adequate amounts of zinc.
When the animals were given about 10 times their dietary requirement for zinc, the biomarkers of inflammation were restored to those of young animals.
“The elderly are the fastest growing population in the U.S. and are highly vulnerable to zinc deficiency,” said Emily Ho, an LPI principal investigator and associate professor in OSU School of Biological and Population Health Sciences. “They don’t consume enough of this nutrient and don’t absorb it very well.”
“We’ve previously shown in both animal and human studies that zinc deficiency can cause DNA damage, and this new work shows how it can help lead to systemic inflammation,” Ho said.
“Some inflammation is normal, a part of immune defense, wound healing and other functions,” she said. “But in excess, it’s been associated with almost every degenerative disease you can think of, including cancer and heart disease. It appears to be a significant factor in the diseases that most people die from.”
As a result of this and what is now know about zinc absorption in the elderly, Ho said that she would recommend all senior citizens take a dietary supplement that includes the full RDA for zinc, which is 11 milligrams a day for men and 8 milligrams for women. Zinc can be obtained in the diet from seafood and meats, but it’s more difficult to absorb from grains and vegetables – a particular concern for vegetarians.
“We found that the mechanisms to transport zinc are disrupted by age-related epigenetic changes,” said Carmen Wong, an OSU research associate and co-author of this study. “This can cause an increase in DNA methylation and histone modifications that are related to disease processes, especially cancer. Immune system cells are also particularly vulnerable to zinc deficiency.”
Research at OSU and elsewhere has shown that zinc is essential to protect against oxidative stress and help repair DNA damage. In zinc deficiency, the risk of which has been shown to increase with age, the body’s ability to repair genetic damage may be decreasing even as the amount of damage is going up.
Medical tests to determine zinc deficiency are rarely done, scientists say, and are not particularly accurate even if they are done. The best approach is to assure adequate intake of the nutrient through diet or supplements, they said, especially in the elderly.
Even though elderly people have less success in absorbing zinc, the official RDA for them is the same as in younger adults. That issue should be examined more closely, Ho said.
Levels of zinc intake above 40 milligrams per day should be avoided, researchers said, because at very high levels they can interfere with absorption of other necessary nutrients, including iron and copper.
These studies were supported by the National Institutes of Health and other agencies.
About the Linus Pauling Institute: The Linus Pauling Institute at OSU is a world leader in the study of micronutrients and their role in promoting optimum health or preventing and treating disease. Major areas of research include heart disease, cancer, aging and neurodegenerative disease.
RELEASE: Fluoxetine increases aggressive behavior, affects brain development among adolescent hamsters
October 1, 2012
BOSTON, Mass.—Fluoxetine was the first drug approved by the FDA for major depressive disorder (MDD) in children and adolescents, and to this date, it remains one of only two selective serotonin reuptake inhibitors (SSRIs) registered for treatment of MDD in children and adolescents, despite reports that indicate this class of drugs is associated with side effects, such as agitation, hostility and aggression.
SSRIs have been amongst the most widely prescribed medications in psychiatry for over a decade. While there is a wealth of information regarding their effectiveness and safety in adults, considerably less data exists regarding whether they are safe for children.
A study published in Behavioral Neuroscience by Prof. Richard Melloni of Northeastern University shows that repeated administration of a low dose of fluoxetine to adolescent hamsters dramatically increased offensive aggression and altered the development of brain areas directly associated with controlling the aggressive response. “These data show clearly that repeated exposure to fluoxetine during adolescence directly stimulates aggressive responding and alters the normal development of two important brain systems, i.e., the serotonin and vasopressin neural systems, in a fashion consistent with the expression of the highly aggressive behavioral characteristics.”
For over a decade, Prof. Melloni and his team have researched the neural and behavioral consequences of illicit drugs and prescribed medications on the adolescent brain. Importantly, the data collected during the study indicates that clinically relevant doses of fluoxetine, when administered during adolescent development, can dramatically alter the wiring of brain circuits implicated in aggression control.“These data support the notion that interactions between adolescent fluoxetine and the developing vasopressin neural system might underlie fluoxetine-induced aggressive behavior and hint that serotonin, perhaps by acting on vasopressin neurons, may play a more permissive role in this response.”
Omega-3 Supplements May Slow A Biological Effect of Aging
COLUMBUS, Ohio – Taking enough omega-3 fatty acid supplements to change the balance of oils in the diet could slow a key biological process linked to aging, new research suggests.
The study showed that most overweight but healthy middle-aged and older adults who took omega-3 supplements for four months altered a ratio of their fatty acid consumption in a way that helped preserve tiny segments of DNA in their white blood cells.
These segments, called telomeres, are known to shorten over time in many types of cells as a consequence of aging. In the study, lengthening of telomeres in immune system cells was more prevalent in people who substantially improved the ratio of omega-3s to other fatty acids in their diet.
Omega-3 supplementation also reduced oxidative stress, caused by excessive free radicals in the blood, by about 15 percent compared to effects seen in the placebo group.
“The telomere finding is provocative in that it suggests the possibility that a nutritional supplement might actually make a difference in aging,” said Jan Kiecolt-Glaser, professor of psychiatry and psychology at Ohio State and lead author of the study.
In another recent publication from this study, Kiecolt-Glaser and colleagues reported that omega-3 fatty acid supplements lowered inflammation in this same group of adults.
“Inflammation in particular is at the heart of so many health problems. Anything that reduces inflammation has a lot of potentially good spinoffs among older adults,” she said.
Study participants took either 2.5 grams or 1.25 grams of active omega-3 polyunsaturated fatty acids, which are considered “good fats” that, when consumed in proper quantities, are associated with a variety of health benefits. Participants on the placebo took pills containing a mix of oils representing a typical American’s daily intake.
The researchers say this combination of effects suggests that omega-3 supplements could represent a rare single nutritional intervention that has potential to lower the risk for a host of diseases associated with aging, such as coronary heart disease, Type 2 diabetes, arthritis and Alzheimer’s disease.
The study is published online and scheduled for later print publication in the journal Brain, Behavior, and Immunity.
Participants received either the placebo or one of the two different doses of omega-3 fatty acids. The supplements were calibrated to contain a ratio of the two cold-water fish oil fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), of seven to one. Previous research has suggested that EPA has more anti-inflammatory properties than DHA.
In the case of fatty acids, omega-3 supplementation alone doesn’t tell the whole story of how this dietary change can affect health, explained Martha Belury, professor of human nutrition at Ohio State and a co-author of the study. Also important is the ratio of omega-6 fatty acids to omega-3 fatty acids that are present in a person’s blood.
Omega-6 fatty acids come from vegetable oils, and since the 1960s, research has suggested that these oils, too, can help protect the cardiovascular system. However, the typical American diet tends to be heavy on omega-6 fatty acids and comparatively low in omega-3s that are naturally found in cold-water fish such as salmon and tuna. While the ratio of omega-6 to omega-3 fatty acids averages about 15-to-1, researchers tend to agree that for maximum benefit, this ratio should be lowered to 4-to-1, or even 2-to-1.
The long chains – or bigger molecules – that make up EPA and DHA fatty acids are believed to be the secret to their effectiveness, Belury said.
Both groups of participants who took omega-3 supplements showed, on average, lengthening of telomeres compared to overall telomere effects in the placebo group, but the relationship could have been attributed to chance. However, when the researchers analyzed the participants’ omega-6 to omega-3 ratio in relationship to telomere lengthening, a lower ratio was clearly associated with lengthened telomeres.
“The idea we were looking at with the ratio of omega-6 to omega-3 fatty acids was an increase in the denominator to make the ratio smaller. In the United States, we need to focus on the omega-3 part because we don’t get enough of those,” Belury said.
The researchers also measured levels of compounds called F2-isoprostanes to determine levels of oxidative stress, which is linked to a number of conditions that include heart disease and neurodegenerative disorders. Both omega-3 groups together showed an average overall 15 percent reduction in oxidative stress compared to effects seen in the placebo group.
When the scientists revisited their earlier inflammation findings, they also found that decreases in an inflammatory marker in the blood called interleukin-6 (IL-6) were associated with telomere lengthening. In their earlier paper on omega-3s and inflammation, they reported that omega-3 supplements lowered IL-6 by 10 to 12 percent, depending on the dose. By comparison, those taking a placebo saw an overall 36 percent increase in IL-6 by the end of the study.
“This finding strongly suggests that inflammation is what’s driving the changes in the telomeres,” Kiecolt-Glaser said.
Telomeres are a hot topic in science, and their tendency to shorten is associated with such age-related problems as heart disease and early mortality. These short fragments of DNA act as caps at the end of chromosomes, and can be likened to the protective plastic at the end of a shoelace.
“If that plastic comes off, the shoelace unravels and it doesn’t work anymore,” said study co-author Ron Glaser, professor of molecular virology, immunology and medical genetics and director of the Institute for Behavioral Medicine Research (IBMR) at Ohio State. “In the same way, every time a cell divides, it loses a little bit of its DNA at the ends, and over time, that can cause significant problems.”
Kiecolt-Glaser noted that this population was disease-free and reported very little stress. The study included 106 adults, average age 51 years, who were either overweight or obese and lived sedentary lives. The researchers excluded people taking medications to control mood, cholesterol and blood pressure as well as vegetarians, patients with diabetes, smokers, those routinely taking fish oil, people who got more than two hours of vigorous exercise each week and those whose body mass index was either below 22.5 or above 40.
“People who are less healthy than this group, and especially those who experience chronic stress, may gain even more benefits from omega-3 supplementation,” she said.
Co-authors of the study include Elissa Epel, Jue Lin and Elizabeth Blackburn of the University of California, San Francisco; Rebecca Andridge and Beom Seuk Hwang of Ohio State’s College of Public Health; and William Malarkey of the IBMR.
This work was supported in part by grants from the National Institutes of Health.
OmegaBrite, a company based in Waltham, Mass., supplied the supplements as an unrestricted gift but did not participate in the study design, results or publication. Study co-authors Blackburn, Epel and Lin are co-founders of Telome Health Inc., a telomere measurement company
Beta-blocker use not associated with lower risk of cardiovascular events
CHICAGO – Among patients with either coronary artery disease (CAD) risk factors only, known prior heart attack, or known CAD without heart attack, the use of beta-blockers was not associated with a lower risk of a composite of cardiovascular events that included cardiovascular death, nonfatal heart attack or nonfatal stroke, according to a study in the October 3 issue of JAMA.
“Treatment with beta-blockers remains the standard of care for patients with coronary artery disease, especially when they have had a myocardial infarction [MI; heart attack]. The evidence is derived from relatively old post-MI studies, most of which antedate modern reperfusion or medical therapy, and from heart failure trials, but has been widely extrapolated to patients with CAD and even to patients at high risk for but without established CAD. It is not known if these extrapolations are justified. Moreover, the long-term efficacy of these agents in patients treated with contemporary medical therapies is not known, even in patients with prior MI,” according to background information in the article.
Sripal Bangalore, M.D., M.H.A., of the NYU School of Medicine, New York, and colleagues conducted a study to evaluate the association between beta-blocker use and long-term cardiovascular outcomes. The observational study included data from patients in the Reduction of Atherothrombosis for Continued Health (REACH) registry. From this registry, 44,708 patients met the study inclusion criteria of whom 14,043 patients (31 percent) had prior MI, 12,012 patients (27 percent) had documented CAD but without MI, and 18,653 patients (42 percent) had CAD risk factors only. The last follow-up data collection was April 2009. The primary outcome for this study was a composite of cardiovascular death, nonfatal MI, or nonfatal stroke. The secondary outcome was the primary outcome plus hospitalization for atherothrombotic events or a revascularization procedure. The overall median (midpoint) follow-up was 44 months. Among the 44,708 patients in the study, 21,860 were included in the propensity score-matched analysis.
The researchers found that in the prior MI group, the event rates were not significantly different among those with beta-blocker use (489 [16.93 percent]) vs. those without beta-blocker use (532 [18.60 percent]) for the primary outcome, or the secondary outcome (30.96 percent vs. 33.12 percent, respectively). In the CAD without MI cohort, the event rates were not different in those with beta-blocker use (391 [12.94 percent]) vs. those without p-blocker use (405 [13.55 percent]) for the primary outcome, for cardiovascular death, for stroke, and for MI. The event rates were higher in those with beta-blocker use (1,101 [30.59 percent] vs. those without beta-blocker use (1,002 [27.84 percent]) for the secondary outcome and for hospitalization in the propensity score-matched model.
In the risk factors alone group, the event rates were higher in those with beta-blocker use (467 [14.22 percent] vs. those without beta-blocker use (403 [12.11 percent]) for the primary outcome, for the secondary outcome (870 [22.01 percent] vs. 797 [20.17 percent], respectively) but not for MI or stroke. In the propensity score-matched model, there were similar event rates for cardiovascular death and for hospitalization.
The researchers also found that among patients with recent MI (one year or less), beta-blocker use was associated with a lower incidence of the secondary outcome.
“Among patients enrolled in the international REACH registry, beta-blocker use was not associated with a lower event rate of cardiovascular events at 44-month follow-up, even among patients with prior history of MI. Further research is warranted to identify subgroups that benefit from beta-blocker therapy and the optimal duration of beta-blocker therapy,” the authors conclude.
Low levels of vitamin D are associated with mortality in older adults
New study shows vitamin D insufficiency more common in African Americans than Caucasians
Chevy Chase, MD—Low levels of vitamin D and high levels of parathyroid hormone are associated with increased mortality in African American and Caucasian older adults, according to a new study accepted for publication in The Endocrine Society’s Journal of Clinical Endocrinology and Metabolism (JCEM). The study also indicates that the potential impact of remediating low vitamin D levels is greater in African Americans than Caucasians because vitamin D insufficiency is more common in African Americans.
For the past several years, there has been considerable interest in the role vitamin D plays in improving health and preventing disease. Low levels of vitamin D have been directly associated with various forms of cancer and cardiovascular disease. Most studies regarding the health effects of low vitamin D levels have been conducted on persons of European origin, but the current study examines the relationship between vitamin D and mortality in blacks and whites.
“We observed vitamin D insufficiency (defined as blood levels <20 ng/ml), in one third of our study participants. This was associated with nearly a 50 percent increase in the mortality rate in older adults,” said Stephen B. Kritchevsky, PhD, Professor of Internal Medicine and Transitional Science at the Wake Forest School of Medicine, and lead researcher of this study. “Our findings suggest that low levels of vitamin D may be a substantial public health concern for our nation’s older adults.”
In this study, 2,638 Caucasians and African-Americans aged 70-79 years were asked to fast for 12-hours, after which a blood sample was collected to determine levels of vitamin D. Every six months study participants were contacted to ascertain their medical condition. This study determined the proportion of deaths among participants of with different vitamin D levels. In addition to many health factors, the time of year was also taken into account due to the seasonal effects on vitamin D. Researchers found that levels of vitamin D less than 30 ng/ml were associated with significantly increased all-cause mortality.
“We all know that good nutrition is important to overall health and our study adds to a growing body of literature that underscores the importance of vitamin D and indicates that poor vitamin D nutrition is wide-spread,” said Kritchevsky. “The good news is it’s easy to improve vitamin D status either through increased skin exposure to sunlight or through diet or supplements.”
‘Superweeds’ linked to rising herbicide use in GM crops
Pesticide use up in GM cotton, soybeans, corn
PULLMAN, Wash. — A study published this week by Washington State University research professor Charles Benbrook finds that the use of herbicides in the production of three genetically modified herbicide-tolerant crops — cotton, soybeans and corn — has actually increased. This counterintuitive finding is based on an exhaustive analysis of publicly available data from the U.S. Department of Agriculture’s National Agriculture Statistics Service. Benbrook’s analysis is the first peer-reviewed, published estimate of the impacts of genetically engineered (GE) herbicide-resistant (HT) crops on pesticide use.
In the study, which appeared in the the open-access, peer-reviewed journal “Environmental Sciences Europe,” Benbrook writes that the emergence and spread of glyphosate-resistant weeds is strongly correlated with the upward trajectory in herbicide use. Marketed as Roundup and other trade names, glyphosate is a broad-spectrum systemic herbicide used to kill weeds. Approximately 95 percent of soybean and cotton acres, and over 85 percent of corn, are planted to varieties genetically modified to be herbicide resistant.
“Resistant weeds have become a major problem for many farmers reliant on GE crops, and are now driving up the volume of herbicide needed each year by about 25 percent,” Benbrook said.
The annual increase in the herbicides required to deal with tougher-to-control weeds on cropland planted to GE cultivars has grown from 1.5 million pounds in 1999 to about 90 million pounds in 2011.
Herbicide-tolerant crops worked extremely well in the first few years of use, Benbrook’s analysis shows, but over-reliance may have led to shifts in weed communities and the spread of resistant weeds that force farmers to increase herbicide application rates (especially glyphosate), spray more often, and add new herbicides that work through an alternate mode of action into their spray programs.
Study: An Apple a Day Lowers Level of Blood Chemical Linked to Hardening of the Arteries
COLUMBUS, Ohio – Eating an apple a day might in fact help keep the cardiologist away, new research suggests.
In a study of healthy, middle-aged adults, consumption of one apple a day for four weeks lowered by 40 percent blood levels of a substance linked to hardening of the arteries.
Taking capsules containing polyphenols, a type of antioxidant found in apples, had a similar, but not as large, effect.
The study, funded by an apple industry group, found that the apples lowered blood levels of oxidized LDL — low-density lipoprotein, the “bad” cholesterol. When LDL cholesterol interacts with free radicals to become oxidized, the cholesterol is more likely to promote inflammation and can cause tissue damage.
“When LDL becomes oxidized, it takes on a form that begins atherosclerosis, or hardening of the arteries,” said lead researcher Robert DiSilvestro, professor of human nutrition at Ohio State University and a researcher at the university’s Ohio Agricultural Research and Development Center. “We got a tremendous effect against LDL being oxidized with just one apple a day for four weeks.”
The difference was similar to that found between people with normal coronary arteries versus those with coronary artery disease, he said.
The study is published online in the Journal of Functional Foods and will appear in a future print edition.
DiSilvestro described daily apple consumption as significantly more effective at lowering oxidized LDL than other antioxidants he has studied, including the spice-based compound curcumin, green tea and tomato extract.
“Not all antioxidants are created equal when it comes to this particular effect,” he said.
DiSilvestro first became interested in studying the health effects of eating an apple a day after reading a Turkish study that found such a regimen increased the amount of a specific antioxidant enzyme in the body.
In the end, his team didn’t find the same effect on the enzyme, but was surprised at the considerable influence the apples had on oxidized LDL.
For the study, the researchers recruited nonsmoking healthy adults between the ages of 40 and 60 who had a history of eating apples less than twice a month and who didn’t take supplements containing polyphenols or other plant-based concentrates.
In all, 16 participants ate a large Red or Golden Delicious apple purchased at a Columbus-area grocery store daily for four weeks; 17 took capsules containing 194 milligrams of polyphenols a day for four weeks; and 18 took a placebo containing no polyphenols. The researchers found no effect on oxidized LDLs in those taking the placebo.
“We got a tremendous effect against LDL being oxidized with just one apple a day for four weeks.”
apples, but we did try to isolate just the polyphenols, using about what you’d get from an apple a day,” DiSilvestro said. “We found the polyphenol extract did register a measurable effect, but not as strong as the straight apple. That could either be because there are other things in the apple that could contribute to the effect, or, in some cases, these bioactive compounds seem to get absorbed better when they’re consumed in foods.”
Still, DiSilvestro said polyphenol extracts could be useful in some situations, “perhaps in higher doses than we used in the study, or for people who just never eat apples.”
The study also found eating apples had some effects on antioxidants in saliva, which has implications for dental health, DiSilvestro said. He hopes to follow up on that finding in a future study.
The study was conducted as a Master’s thesis by graduate student Shi Zhao, and was funded by a grant from the U.S. Apple Association/Apple Product Research and Education Council and a donation from Futureceuticals Inc. of Momence, Ill.
Also involved in the study were associate professor Joshua Bomser and research associate Elizabeth Joseph, both in the Department of Human Nutrition, which is housed in the university’s College of Education and Human Ecology.
New study links caffeinated coffee to vision loss
Rockville, MD – A new study suggests caffeinated coffee drinkers should limit their intake to reduce their chances of developing vision loss or blindness. According to a scientific paper in Investigative Ophthalmology & Visual Science, heavy caffeinated coffee consumption is associated with an increased risk of developing exfoliation glaucoma, the leading cause of secondary glaucoma worldwide.
The study, The Relation between Caffeine and Coffee Consumption and Exfoliation Glaucoma or Glaucoma Suspect: A Prospective Study in Two Cohorts, is the first to examine the link between caffeinated coffee and exfoliation glaucoma in a U.S. –based population.
“Scandinavian populations have the highest frequencies of exfoliation syndrome and glaucoma,” said author, Jae Hee Kang, ScD, of Channing Division of Network Medicine at Brigham and Women’s Hospital in Boston, Mass. “Because Scandinavian populations also have the highest consumption of caffeinated coffee in the world, and our research group has previously found that greater caffeinated coffee intake was associated with increased risk of primary open-angle glaucoma, we conducted this study to evaluate whether the risk of exfoliation glaucoma or glaucoma suspect may be different by coffee consumption.”
The study was composed of two cohorts: 78,977 women from the Nurses’ Health Study (NHS) and 41,202 men from the Health Professionals Follow-up Study (HPFS) who were at least 40 years of age, did not have glaucoma and reported undergoing eye examinations from 1980 (for NHS participants) and 1986 (for HPFS participants) to 2008. The research team used questionnaires to obtain and validate the consumption of beverages containing caffeine and reviewed medical records to determine incident cases of exfoliation glaucoma, which contributes to elevated pressure sufficient enough to damage the optic nerve, or exfoliation glaucoma suspect that have milder or only suspect optic nerve damage.
A meta-analysis of the two cohorts showed that, compared to abstainers, participants who drank three cups or more of caffeinated coffee daily were at an increased risk of developing exfoliation glaucoma or glaucoma suspect. The researchers did not find associations with consumption of other caffeinated products, such as soda, tea, chocolate or decaffeinated coffee. The results also showed that women with a family history of glaucoma were at an increased risk.
Kang, along with his colleagues, report that this study represents a much needed effort to better understand the causes of exfoliation glaucoma, which are largely unknown.
“Because this is the first study to evaluate the association between caffeinated coffee and exfoliation glaucoma in a U.S. population, confirmation of these results in other populations would be needed to lend more credence to the possibility that caffeinated coffee might be a modifiable risk factor for glaucoma,” said Kang. “It may also lead to research into other dietary or lifestyle factors as risk factors.
New study sheds light on cancer-protective properties of milk
Findings reported in the Journal of Dairy Science
Amsterdam, The Netherlands, October 3, 2012 – Milk consumption has been linked to improved health, with decreased risks of diabetes, metabolic syndrome, and colon cancer. A group of scientists in Sweden found that lactoferricin4-14 (Lfcin4-14), a milk protein with known health effects, significantly reduces the growth rate of colon cancer cells over time by prolonging the period of the cell cycle before chromosomes are replicated. In a new study, investigators report that treatment with Lfcin4-14 reduced DNA damage in colon cancer cells exposed to ultraviolet (UV) light. Their results are published in the October issue of the Journal of Dairy Science®.
“We previously hypothesized that the prolongation of the cell cycle in colon cancer cells as a result of Lfcin4-14 treatment may give the cells extra time for DNA repair,” says one of the lead investigators, Professor Stina Oredsson, of the Department of Biology at the University of Lund, Sweden. “Indeed, UV light-induced damage was decreased in colon cancer cells treated with Lfcin4-14 compared with controls. The differences were small but significant.”
Investigators exposed colon cancer cells to UV light that caused DNA damage and then grew the cells in the absence or presence of Lfcin4-14. They evaluated DNA damage using a sensitive technique known as comet assay. After the cells are processed, the cells with DNA damage resemble a comet with a tail, and the intensity of the tail compared to the comet head indicates the number of DNA breaks. UV light exposure resulted in an increase in the number of comets while treatment with Lfcin4-14 reduced the number of comets in UV light-exposed cells.
To understand the mechanism by which Lfcin4-14 reduced DNA damage, investigators evaluated the levels of several proteins involved in cell cycle progression, DNA repair, and cell death. They found an increase in flap endonuclease-1, a protein associated with DNA synthesis; a decrease in b-cell lymphoma 2-associated X protein, which is involved with cell death; and a decrease in the level of g-H2AX, indicating more efficient DNA repair. “These changes in expression support our hypothesis that Lfcin4-14 treatment resulted in increased DNA repair,” says Dr. Oredsson.
Dr. Oredsson notes that cancer cells, in general, have defects in the DNA repair mechanisms. Thus, Lfcin4-14 may have a greater effect on normal cells than on cancer cells. “Our data suggest that the effects of Lfcin4-14 in prolonging the cell cycle may contribute to the cancer preventive effect of milk. This must be further investigated in different systems,” she concludes.
BPA linked to thyroid hormone changes in pregnant women, newborns
Berkeley — Bisphenol A (BPA), an estrogen-like compound that has drawn increased scrutiny in recent years, has been linked to changes in thyroid hormone levels in pregnant women and newborn boys, according to a new study by researchers at the University of California, Berkeley.
Normal thyroid function is essential to the healthy growth and cognitive development of fetuses and children. Yet, until this study, to be published Thursday, Oct. 4, in the journal Environmental Health Perspectives, little was known about the effects of BPA exposure on thyroid hormones in pregnant women and newborns.
The new findings add to growing health concerns about BPA, a chemical found in hard plastics, linings of canned food, dental sealants, and sales receipts on thermal paper, which is coated with a chemical that changes color when exposed to heat. In July, the U.S. Food and Drug Administration officially banned the chemical in baby bottles and cups, something the industry began doing voluntarily in recent years in response to consumer concerns about the potential risks of BPA.
The researchers analyzed BPA levels in the urine samples of 335 women during the second half of pregnancy, and thyroid hormone levels in blood samples taken from the mothers during pregnancy and from the newborns within a few days of birth. The participants were part of the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) study led by Brenda Eskenazi, UC Berkeley professor of epidemiology and of maternal and child health.
The researchers found that for each doubling of BPA levels, there was an associated decrease of 0.13 micrograms per deciliter of total thyroxine (T4) in mothers during pregnancy, which suggests a hypothyroid effect. For newborn boys, each doubling of BPA levels linked to a 9.9 percent decrease in thyroid stimulating hormone (TSH), indicating a hyperthyroid effect.
“Most of the women and newborns in our study had thyroid hormone levels within a normal range, but when we consider the impact of these results at a population level, we get concerned about a shift in the distribution that would affect those on the borderline,” said study lead author Jonathan Chevrier, research epidemiologist at UC Berkeley’s Center for Environmental Research and Children’s Health (CERCH). “In addition, studies suggest that small changes in thyroid level, even if they’re within normal limits, may still have a cognitive effect.”
It was not clear why an association was not found among newborn girls, but animal studies may provide some clues. One study in neonatal rats found a similar hyperthyroidic effect in males, but not females. Another study found that female rats had higher levels of an enzyme important in metabolizing BPA when compared with their male counterparts. Whether that same relationship holds true for humans is not yet clear.
“In addition, studies in rodents are increasingly showing that BPA can have different effects in males and females, particularly in brain development and behavior,” said the study’s senior author, Kim Harley, adjunct associate professor of public health and associate director of CERCH.
The researchers pointed out that several studies in recent years have linked lower thyroid hormone levels to delays in cognitive and motor development in young children. Two years ago, the same group of UC Berkeley researchers also found links between PBDEs (polybrominated diphenyl ethers), a class of flame retardants, and changes in thyroid hormone levels.
They were confident that the BPA was acting on thyroid hormones independently from PBDEs, because levels of the two compounds were not correlated.
“There is good reason to be concerned about PBDEs and BPA, because both of these compounds are ubiquitous in our environment,” said Harley. “More than 90 percent of women of reproductive age have detectable levels of BPA in their urine, and some 97 percent of U.S. residents have detectable levels of PBDEs in their blood. Until we learn more about the human health effects of these chemicals, it would make sense to be cautious and avoid exposure when possible, particularly for those who are pregnant.”
Chewing ability linked to reduced dementia risk
[NEWS, 4 October 2012] Can you bite into an apple? If so, you are more likely to maintain mental abilities, according to new research from Karolinska Institutet.
The population is ageing, and the older we become the more likely it is that we risk deterioration of our cognitive functions, such as memory, decision-making and problem solving. Research indicates several possible contributors to these changes, with several studies demonstrating an association between not having teeth and loss of cognitive function and a higher risk of dementia.
One reason for this could be that few or no teeth makes chewing difficult, which leads to a reduction in the blood flow to the brain. However, to date there has been no direct investigation into the significance of chewing ability in a national representative sample of elderly people.
Now a team comprised of researchers from the Department of Odontology and the Aging Research Center (ARC) at Karolinska Institutet and from Karlstad University have looked at tooth loss, chewing ability and cognitive function in a random nationwide sample of 557 people aged 77 or older. They found that those who had difficulty chewing hard food such as apples had a significantly higher risk of developing cognitive impairments. This correlation remained even when controlling for sex, age, education and mental health problems, variables that are often reported to impact on cognition. Whether chewing ability was sustained with natural teeth or dentures also had no bearing on the effect.
The results are published in the Journal of the American Geriatrics Society (JAGS). The study was financed with grants from several funds, including the Swedish Council for Working Life and Social Research and the Swedish Research Council.
Society, online ahead of print 4 October 2012
Tree Nut Research May Unexpectedly Lead to Medical Advances / Thyme
By Marcia Wood
October 5, 2012
Prescription drugs that today help patients fight severe fungal infections might tomorrow be even more effective, thanks to unexpected findings from agriculture-based, food-safety-focused studies by U.S. Department of Agriculture (USDA) scientists and their colleagues.
Petri-dish experiments conducted by now-retired Agricultural Research Service (ARS) research leader Bruce C. Campbell, ARS molecular biologist Jong H. Kim, and their co-investigators suggest that pairing conventional antifungal medicines with natural, edible compounds from plants—such as thymol, extracted from the popular herb thyme—can boost the healing effects of some of these drugs. ARS is the chief intramural scientific research agency of USDA.
Campbell and Kim’s work at the ARS Western Regional Research Center in Albany, Calif., with species of Aspergillus mold, for example, has attracted the attention of medical and public health researchers. Found worldwide in air and soil, Aspergillus can infect corn, cotton, pistachios, almonds and other crops, and can produce aflatoxin, a natural carcinogen.
Aflatoxin-contaminated crops must be identified and removed from the processing stream, at times resulting in large economic losses. Since 2004, Campbell, Kim, and colleagues have carefully built a portfolio of potent, plant-based compounds that kill a target Aspergillus species, A. flavus, or thwart its ability to produce aflatoxin.
Further research and testing might enable tomorrow’s growers to team the best of these natural compounds with agricultural fungicides that today are uneconomical to use, according to Kim.
A. flavus and two of its relatives, A. fumigatus and A. terreus, may impact the health of immunocompromised individuals exposed to the fungus in moldy homes. In a 2010 article in Fungal Biology, the team reported that thymol, when used in laboratory tests with two systemic antifungal medications, inhibited growth of these fungi at much lower-than-normal doses of the drugs.
A related study provided new evidence to support earlier findings, at Albany and elsewhere, which had suggested that plant compounds such as thymol may sabotage a target fungi’s ability to recover from oxidative stress triggered by antifungal drugs. A 2011 article published by Kim, Campbell and others in Annals of Clinical Microbiology and Antimicrobials documents this research.
Using plant-derived compounds to treat fungal infections is not a new idea, nor is that of pairing the compounds with antifungal medicines. But the Albany team’s studies have explored some apparently unique pairs, and have provided some of the newest, most detailed information about the mechanisms likely responsible for the impact of powerful combinations of drugs and natural plant compounds.
Read more about this research in the October 2012 issue of Agricultural Research magazine.
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