Monday, January 31, 2011
How maternal essential fatty acid deficiency impact on its progeny is poorly understood. Dietary insufficiency in omega-3 fatty acid has been implicated in many disorders. Researchers from Inserm and INRA and their collaborators in Spain collaboration, have studied mice fed on a diet low in omega-3 fatty acid. They discovered that reduced levels of omega-3 had deleterious consequences on synaptic functions and emotional behaviours. Details of this work are available in the online version of the journal Nature neuroscience, which can be accessed at: http://dx.doi.org/10.1038/nn.2736
In industrialized nations, diets have been impoverished in essential fatty acids since the beginning of the 20th century. The dietary ratio between omega-6 polyunsaturated fatty acid and omega-3 polyunsaturated fatty acid omega-3 increased continuously over the course of the 20th century. These fatty acids are "essential" lipids because the body cannot synthesize them from new. They must therefore be provided through food and their dietary balance is essential to maintain optimal brain functions.
Olivier Manzoni (Head of Research Inserm Unit 862, "Neurocentre Magendie", in Bordeaux and Unit 901 "Institut de Neurobiologie de la Méditerranée" in Marseille), and Sophie Layé (Head of Research at INRA Unit 1286, "Nutrition et Neurobiologie Intégrative" in Bordeaux) and their co-workers hypothesized that chronic malnutrition during intra-uterine development, may later influence synaptic activity involved in emotional behaviour (e.g. depression, anxiety) in adulthood.
To verify their hypotheses, the researchers studied mice fed a life-long diet imbalanced in omega-3 and omega-6 fatty acids. They found that omega-3 deficiency disturbed neuronal communication specifically. The researchers observed that only the cannabinoid receptors, which play a strategic role in neurotransmission, suffer a complete loss of function. This neuronal dysfunction was accompanied by depressive behaviours among the malnourished mice.
Among omega-3 deficient mice, the usual effects produced by cannabinoid receptor activation, on both the synaptic and behavioural levels, no longer appear. Thus, the CB1R receptors lose their synaptic activity and the antioxidant effect of the cannabinoids disappears.
Consequently, the researchers discovered that among mice subjected to an omega-3 deficient dietary regime, synaptic plasticity, which is dependent on the CB1R cannabinoid receptors, is disturbed in at least two structures involved with reward, motivation and emotional regulation: the prefrontal cortex and the nucleus accumbens. These parts of the brain contain a large number of CB1R cannabinoid receptors and have important functional connections with each other.
"Our results can now corroborate clinical and epidemiological studies which have revealed associations between an omega-3/omega-6 imbalance and mood disorders", explain Olivier Manzoni and Sophie Layé. "To determine if the omega-3 deficiency is responsible for these neuropsychiatric disorders additional studies are, of course, required".
In conclusion, the authors estimate that their results provide the first biological components of an explanation for the observed correlation between omega-3 poor diets, which are very widespread in the industrialized world, and mood disorders such as depression.
A new study published in the journal Clinical Cardiology reveals that a Super Bowl loss for a home team was associated with increased death rates in both men and women and in older individuals.
Sports fans may be emotionally involved in watching their favorite teams. When the team loses, it can cause some degree of emotional stress.
Led by Robert A. Kloner, MD, PhD, of the Heart Institute, Good Samaritan Hospital and Keck School of Medicine at USC in Los Angeles, researchers assessed how often this emotional stress may translate to increases in cardiac death. They ran regression models for mortality rates for cardiac causes for the 1980 Los Angeles Super Bowl loss and for the 1984 Los Angeles Super Bowl win.
Results show that the Los Angeles Super Bowl loss of 1980 increased total and cardiac deaths in both men and women and triggered more death in older than younger patients. In contrast, there was a trend for a Super Bowl win to reduce death more frequently in older people and in women.
Specifically, in men there was a 15 percent increase in all circulatory deaths associated with the Super Bowl loss; in women there was a 27 percent increase in all circulatory deaths associated with the loss. Thus, unlike previous reports from some soccer games, the findings were not confined mainly to male fans, but also were seen in women. In older patients, there was a 22 percent increase in circulatory deaths associated with the Super Bowl loss.
"Physicians and patients should be aware that stressful games might elicit an emotional response that could trigger a cardiac event," Kloner notes. "Stress reduction programs or certain medications might be appropriate in individual cases."
A new study shows that one year of moderate physical exercise can increase the size of the brain's hippocampus in older adults, leading to an improvement in spatial memory.
The project—conducted by researchers at the University of Pittsburgh, University of Illinois, Rice University, and Ohio State University—is considered the first study of its kind focusing on older adults who are already experiencing atrophy of the hippocampus, the brain structure involved in all forms of memory formation. The study, funded through the National Institute on Aging, appears in the Jan. 31 Proceedings of the National Academy of Sciences (PNAS).
The scientists recruited 120 sedentary older people without dementia and randomly placed them in one of two groups—those who began an exercise regimen of walking around a track for 40 minutes a day, three days a week, or those limited to stretching and toning exercises. Magnetic resonance images were collected before the intervention, after six months, and at the end of the one-year study.
The aerobic exercise group demonstrated an increase in volume of the left and right hippocampus of 2.12 percent and 1.97 percent, respectively. The same regions of the brain in those who did stretching exercises decreased in volume by 1.40 and 1.43 percent, respectively.
Spatial memory tests were conducted for all participants at the three intervals. Those in the aerobic exercise group showed improved memory function, when measured against their performance at the start of the study, an improvement associated with the increased size of the hippocampus. The authors also examined several biomarkers associated with brain health, including brain-derived neurotrophic factor (BDNF), a small molecule that is involved in learning and memory. They found that the increases in hippocampal size were associated with increased amounts of BDNF.
"We think of the atrophy of the hippocampus in later life as almost inevitable," said Kirk Erickson, professor of psychology at the University of Pittsburgh and the paper's lead author. "But we've shown that even moderate exercise for one year can increase the size of that structure. The brain at that stage remains modifiable."
"The results of our study are particularly interesting in that they suggest that even modest amounts of exercise by sedentary older adults can lead to substantial improvements in memory and brain health," said Art Kramer, director of the Beckman Institute at the University of Illinois and the senior author.
"Such improvements have important implications for the health of our citizens and the expanding population of older adults worldwide."
Consumption of red wine or other sources of polyphenols) should begin earlier in life to slow down the endothelial dysfunction that occurs with aging
Young rats given polyphenols show less endothelial function deterioration with aging
The endothelium is the inner lining of our blood vessels and normal functions of endothelial cells include enabling coagulation, platelet adhesion and immune function. Endothelial dysfunction is associated with reduced anticoagulant properties and the inability of arteries and arterioles to dilate fully.
The gradual decrease in endothelial function over time is a key factor in the development of diseases associated with ageing, especially cardiovascular disease (CVD). Many epidemiologic studies suggest protection against CVD from moderate intake of alcoholic beverages, especially those rich in antioxidants, such as red wine, which is high in polyphenols (RWPs).
This study examined whether intake of red wine polyphenols (RWPs), a rich source of natural antioxidants, prevents ageing-related impairment of vascular function and physical exercise capacity. Vascular reactivity from 12, 20 and 40 week-old rats was assessed in organ chambers. Rats received from week 16 to 40 either solvent, RWPs or the antioxidant and NADPH oxidase inhibitor, apocynin. RWPs and apocynin improved the endothelial dysfunction, normalized oxidative stress and the expression of the different proteins. RWPs also improved ageing-related decline in physical exercise. Thus, intake of RWPs protects against ageing-induced endothelial dysfunction and decline in physical performance. These effects likely involve the ability of RWPs to normalize oxidative stress and the expression of proteins involved in the formation of NO and the angiotensin II pathway.
International Scientific Forum on Alcohol Research members thought that this was an excellent paper, as it begins to delve into mechanisms by which polyphenols improve health. A mechanism is addressed and results are consistent with the working hypothesis of a specific interaction between polyphenols and peculiar enzymes. There is a satisfying agreement between basic mechanisms and pathophysiology. Some scientists believe that interventions to improve endothelial function (such as the consumption of red wine or other sources of polyphenols) should begin earlier in life to slow down the endothelial dysfunction that occurs with ageing. This study in rats tends to support such a belief.
The present study in rats found that the administration of red wine polyphenols protected against ageing-induced endothelial dysfunction. As stated by the authors: "The present findings indicate that regular intake of RWPs in the drinking water starting at young age (16 week-old) prevented the ageing-related endothelial dysfunction most likely by reducing the excessive oxidative stress in the arterial wall." They suggest an important role of NADPH oxidase and possibly also the angiotensin system in the abnormal vascular response in ageing. Their study showed that, "RWPs intake had also a physiological beneficial effect since it improved the physical exercise capacity of old rats."
Saturday, January 29, 2011
Researchers have demonstrated that the ingestion of trans-fats and saturated fats increase the risk of suffering depression, and that olive oil, on the other hand, protects against this mental illness.
They have confirmed this after studying 12,059 SUN Project volunteers over the course of six years; the volunteers had their diet, lifestyle and ailments analyzed at the beginning of the project, over its course and at the end of the project. In this way the researchers confirmed that despite the fact that at the beginning of the study none of the volunteers suffered from depression, at the end of the study 657 new cases had been detected.
Of all these cases, the participants with an elevated consumption of trans-fats (fats present in artificial form in industrially-produced pastries and fast food, and naturally present in certain whole milk products) "presented up to a 48% increase in the risk of depression when they were compared to participants who did not consume these fats," affirmed Almudena Sánchez-Villegas, Associate Professor of Preventive Medicine at the University of Las Palmas de Gran Canaria, first author of the article.
In addition, the study demonstrated a dose-response relationship, "whereby the more trans-fats were consumed, the greater the harmful effect they produced in the volunteers," the expert stated.
Furthermore, the team, directed by Miguel Ángel Martínez-González, Professor of Preventive Medicine at the University of Navarra, also analyzed the influence of polyunsaturated fats (abundant in fish and vegetable oils) and of olive oil on the occurrence of depression. "In fact, we discovered that this type of healthier fats, together with olive oil, are associated with a lower risk of suffering depression," emphasized the researcher and director of the SUN Project.
150 million persons depressed worldwide
Thus, the results of the study corroborate the hypothesis of a greater incidence of the disease in countries of the north of Europe compared to the countries of the south, where a Mediterranean dietary pattern prevails. Nevertheless, experts have noted that the incidence of the disease has increased in recent years, so that today some 150 million persons are affected worldwide, where it is the principal cause of loss of years of life in those countries with a medium-to-high per capita income.
This due, according to Almudena Sánchez Villegas, "to radical changes in the sources of fats consumed in Western diets, where we have substituted certain types of beneficial fats -- polyunsaturated and monounsaturated in nuts, vegetable oils and fish -- for the saturated and trans-fats found in meats, butter and other products such as mass-produced pastries and fast food."
In addition, the research -- published in the online peer reviewed journal PLoS ONE -- has been performed on a population with a low average intake of trans-fats, given that it made up only 0.4% of the total energy ingested by the volunteers. "Despite this, we observed an increase in the risk of suffering depression of nearly 50%. On this basis," concluded Miguel A. Martínez, "we derive the importance of taking this effect into account in countries like the U.S., where the percentage of energy derived from these foots is around 2.5%."
Finally, the analysis, headed by the University of Navarra and the University of Las Palmas de Gran Canaria, suggests that both depression as well as cardiovascular disease are influenced in a similar manner by diet, and might share similar mechanisms in their origin. This hypothesis is further suggested by numerous studies that indicate the harmful effect of trans-fats and saturated fats on the risk of cardiovascular disease.
Thursday, January 27, 2011
A new University of Illinois study provides convincing evidence that the way you prepare and consume your broccoli matters, and also suggests that teaming broccoli with broccoli sprouts may make the vegetable's anti-cancer effect almost twice as powerful.
"Broccoli, prepared correctly, is an extremely potent cancer-fighting agent—three to five servings a week are enough to have an effect. To get broccoli's benefits, though, the enzyme myrosinase has to be present; if it's not there, sulforaphane, broccoli's cancer-preventive and anti-inflammatory component, doesn't form," said Elizabeth Jeffery, a U of I professor of nutrition.
According to Jeffery, many people destroy myrosinase by overcooking their broccoli. And health-conscious consumers who use broccoli powder supplements in recipes to boost their nutrition are also missing out. These supplements often do not contain this necessary enzyme, she said.
"There is a way to boost that powder's effectiveness, though. Broccoli sprouts contain myrosinase in abundance. And broccoli powder often contains the precursor to sulforaphane without the enzyme that would boost its healthful benefits," said Jenna Cramer, co-author of the study.
The scientists hypothesized that myrosinase from the sprouts would enhance sulforaphane formation and absorption from the broccoli powder if the two were eaten together.
In a small pilot study, they recruited four healthy men who ate meals that contained broccoli sprouts alone, broccoli powder alone, or a combination of the two. The researchers then measured levels of sulforaphane metabolites in the mens' blood and urine after feeding.
"We were looking at biomarkers—plasma and urine levels—that are associated with cancer prevention," Cramer said.
Three hours after feeding, a definite synergistic effect was noted between the powder and the sprouts.
"There was almost a twofold increase in sulforaphane absorption when sprouts and powder were eaten together. It changed the way the subjects metabolized the powder. We saw plasma and urine metabolites much earlier and at much higher levels than when either was eaten alone," Jeffery said.
This indicates that myrosinase from the broccoli sprouts produced sulforaphane not only from the sprouts but also from the precursor present in the broccoli powder, she said.
Other foods that contain sulforaphane and can be teamed with broccoli to boost its benefits are mustard, radishes, arugula, and wasabi, Jeffery said.
"To increase the vegetable's benefits, you could sprinkle broccoli sprouts on your broccoli or make a mustard sauce to serve with broccoli," she added.
People who prefer to eat broccoli without sauce or sprouts should know that overcooking is the kiss of death for the important enzyme myrosinase, she said.
"Steaming broccoli for two to four minutes is the perfect way to protect both the enzyme and the vegetable's nutrients," she said.
Wednesday, January 26, 2011
But there also are risks. The Women's Health Initiative found that taking estrogen plus progestin increased women's risks of heart disease, blood clots, stroke and breast cancer.
New research shows that vitamin D deficiency is prevalent among patients with interstitial lung disease (ILD), with the largest prevalence seen in patients with concurrent connective tissue disease (CTD). Researchers from the University of Cincinnati College of Medicine evaluated vitamin D levels in 67 patients with CTD-ILD and 51 patients with other forms of ILD. Results showed the overall prevalence of vitamin D deficiency and insufficiency was 38 percent and 59 percent, respectively. Those with CTD-ILD were more likely to have vitamin D deficiency (52 percent vs 20 percent) and insufficiency (79 percent vs 31 percent) than other forms of ILD. Among patients with CTD-ILD, reduced vitamin D levels were strongly associated with reduced lung function. Researchers conclude that vitamin D may have a role in the pathogenesis of CTD-ILD. This article is published in the February issue of Chest, the peer-reviewed journal of the American College of Chest Physicians: Chest 2011; 139(2):353-360.
Tuesday, January 25, 2011
If you follow the news about health research, you risk whiplash. First garlic lowers bad cholesterol, then—after more study—it doesn’t. Hormone replacement reduces the risk of heart disease in postmenopausal women, until a huge study finds that it doesn’t (and that it raises the risk of breast cancer to boot). Eating a big breakfast cuts your total daily calories, or not—as a study released last week finds. Yet even if biomedical research can be a fickle guide, we rely on it.
But what if wrong answers aren’t the exception but the rule? More and more scholars who scrutinize health research are now making that claim. It isn’t just an individual study here and there that’s flawed, they charge. Instead, the very framework of medical investigation may be off-kilter, leading time and again to findings that are at best unproved and at worst dangerously wrong. The result is a system that leads patients and physicians astray—spurring often costly regimens that won’t help and may even harm you..
In just the last two months, two pillars of preventive medicine fell. A major study concluded there’s no good evidence that statins (drugs like Lipitor and Crestor) help people with no history of heart disease. The study, by the Cochrane Collaboration, a global consortium of biomedical experts, was based on an evaluation of 14 individual trials with 34,272 patients. Cost of statins: more than $20 billion per year, of which half may be unnecessary. (Pfizer, which makes Lipitor, responds in part that “managing cardiovascular disease risk factors is complicated”). In November a panel of the Institute of Medicine concluded that having a blood test for vitamin D is pointless: almost everyone has enough D for bone health (20 nanograms per milliliter) without taking supplements or calcium pills. Cost of vitamin D: $425 million per year...
Friday, January 21, 2011
There is not enough evidence to recommend the widespread use of statins in people with no previous history of heart disease, according to a new Cochrane Systematic Review. Researchers say statins should be prescribed with caution in those at low risk of cardiovascular disease (CVD).
CVD is the most common cause of death, accounting for nearly a third of all deaths worldwide. Cholesterol-lowering statins are first line treatments for heart patients and the benefits are well established. However, there is less evidence that statins are beneficial for preventing heart problems in those who have no history of CVD. Given that low cholesterol has been shown to increase the risk of death from other causes, statins may do more harm than good in some patients.
The researchers reviewed data from 14 trials involving 34,272 patients. Outcomes in patients given statins were compared to outcomes in patients given placebos or usual care. Combined data from eight trials involving 28,161 patients that provided data on deaths from all causes showed that statins reduced the risk of dying from 9 to 8 deaths for every 1000 people treated with statins each year. Statins reduced fatal and non-fatal events, including heart attack, stroke and revascularization surgery, as well as blood cholesterol levels.
However, the researchers say that the conclusions of their review are limited by unclear, selective and potentially biased reporting and that careful consideration should be given to patients' individual risk profiles before prescribing statins.
"It is not as simple as just extrapolating the effects from studies in people who have a history of heart disease," said lead researcher Fiona Taylor, from the Cochrane Heart Group at the London School of Hygiene and Tropical Medicine in London, UK. "This review highlights important shortcomings in our knowledge about the effects of statins in people who have no previous history of CVD. The decision to prescribe statins in this group should not be taken lightly."
The researchers point out that all but one of the trials they reviewed were industry-sponsored. "We know that industry-sponsored trials are more likely to report favourable results for drugs versus placebos, so we have to be cautious about interpreting these results," said Taylor. "The numbers eligible for treatment with statins are potentially great so there might be motivations, for instance, to stop trials earlier if interim results support their use."
A separate Cochrane Systematic Review, conducted by some of the same authors, considered the effects of combined approaches to reducing the risk of heart disease, including using education and counselling to encourage people to change their diets and stop smoking. The authors concluded that combined interventions had little or no impact on deaths or disease caused by CVD. In an editorial accompanying the reviews, Carl Heneghan, University of Oxford, concluded that, "Although various multiple prevention strategies exist, the most effective and cost-effective intervention for primary prevention in adults at low risk currently remains unclear."
Thursday, January 20, 2011
Depending on the level of smoking and dietary vitamin C intake, vitamin E supplementation may extend the life-span of restricted groups of men, according to a study published in the Age and Ageing.
Several large randomized trials of humans found that vitamin E supplementation does not reduce mortality. However, the average effect on mortality in a group of people with a wide age range may mask an effect of vitamin E on the life-span.
Dr. Harri Hemila, and Professor Jaakko Kaprio, of the University of Helsinki, Finland, studied the age-dependency of vitamin E effect on mortality in the large randomized trial (Alpha-Tocopherol Beta-Carotene Cancer Prevention Study) which was conducted in Finland between 1985-1993. Their study was restricted to follow-up period over 65 years and 10,837 participants contributed to the analysis.
Among all analyzed participants, vitamin E had no effect on mortality when participants were 65 to 70 years old, but reduced mortality by 24% when participants were 71 or older.
Among 2,284 men with dietary vitamin C intake above the median who smoked less than a pack of cigarettes per day, vitamin E extended life-span by two years at the upper limit of the follow-up age span. In the other participants, consisting of 80% of the cohort, vitamin E did not affect mortality, which shows that vitamin E is no panacea for extending life expectancy.
The researchers concluded that "if vitamin E influences the life-span, it is possible that a benefit on the oldest participants might be camouflaged by the large middle-aged majority of study participants". Therefore, they propose that it might be useful to analyze the effect of vitamin E supplementation in large controlled trials by the age of the participant at the follow-up and not just by the time after randomization that has been customary.
The notion that feeling good may be good for your health is not new, but is it really true? A new article published in Current Directions in Psychological Science, a journal of the Association for Psychological Science, reviews the existing research on how positive emotions can influence health outcomes in later adulthood.
“We all age. It is how we age, however, that determines the quality of our lives,” said Anthony Ong of Cornell University, author of the review article. The data he reviews suggest that positive emotions may be a powerful antidote to stress, pain, and illness.
There are several pathways through which a positive attitude can protect against poor health later in life. For example, happier people might take a proactive approach to aging by regularly exercising and budgeting time for a good night’s sleep. Alternately, these people may avoid unhealthy behaviors, such as smoking and risky sex. The benefits of these healthy lifestyle choices may become more important in older adults, as their bodies become more susceptible to disease.
An optimistic outlook has also been shown to combat stress—a known risk factor for a lot of disease. Studies have found that people with stronger positive emotions have lower levels of chemicals associated with inflammation related to stress. Also, by adopting a positive attitude people may even be able to undo some of the physical damage caused by stress.
Ong, a developmental psychologist, became interested in the study of positive emotion during graduate school when he learned about what researchers call the paradox of aging: Despite the notable loss of physical function throughout the body, a person’s emotional capacity seemed to stay consistent with age. Ong speculates that if positive emotions are indeed good for
Many newspapers are reporting on new research about statins - this report is typical:
But not according to the most recent review of the many trials investigating their effectiveness, published yesterday. It suggests that for three quarters of those taking them, they offer little or no value, while exposing millions to the hazard of undesirable side-effects.
But this is lousy reporting - the actual research conclusion is: "All cause mortality. coronary heart disease and stroke events were reduced with the use of statins....Taking statins did not increase the risk of adverse effects such as cancer." No mention of undesirable side-effects.
The researchers mainly criticized the quality of the research, and advised exercising caution:
"There was evidence of selective reporting of outcomes, failure to report adverse events and inclusion of people with cardiovascular disease. Only limited evidence showed that primary prevention with statins may be cost effective and improve patient quality of life. "
A European study investigating the links between diet and disease has found that people who consume more fruit and vegetables have a lower risk of dying from ischaemic heart disease -- the most common form of heart disease and one of the leading causes of death in Europe. However, the authors point out that a higher fruit and vegetable intake occurs among people with other healthy eating habits and lifestyles, and that these factors could also be associated with the lower risk of dying from IHD.
The study is published online on January 19 in the European Heart Journal.
Data analysed from the European Prospective Investigation into Cancer and Nutrition (EPIC) Heart study has shown that people who ate at least eight portions of fruit and vegetables a day had a 22% lower risk of dying from IHD than did those who consumed fewer than three portions a day. A portion weighed 80 grams, equal to a small banana, a medium apple, or a small carrot.
Dr Francesca Crowe of the Cancer Epidemiology Unit at the University of Oxford, UK, and the first author of the paper by the EPIC study collaborators, said: "This study involved over 300,000 people in eight different European countries, with 1,636 deaths from IHD. It shows a 4% reduced risk of dying from IHD for each additional portion of fruit and vegetables consumed above the lowest intake of two portions. In other words, the risk of a fatal IHD for someone eating five portions of fruit and vegetables a day would be 4% lower compared to someone consuming four portions a day, and so on up to eight portions or more."
Ischaemic heart disease (IHD) is characterised by reduced blood supply to the heart; people suffering from it can develop angina, chest pains and have a heart attack.
The EPIC study started in 1992 and recruited participants from a total of ten European countries* until 2000. For the analysis of IHD deaths, data from eight countries for people aged between 40 and 85 were used. Participants answered questions about their diet at the time of entry to the study and other questions about health, socio-economic status and life-style, such as smoking, drinking and exercise habits. They were followed-up for an average of nearly eight and a half years.
The researchers found that the average intake of fruit and vegetables was five portions a day; people in Greece, Italy and Spain ate more, and those in Sweden ate less.
When analysing the data, the researchers made allowances for confounding factors such as differences in lifestyles and eating habits. However, the study could be limited by errors in measuring correctly people's fruit and vegetable intake as well as other aspects of their diet. In addition, the study had a higher proportion of women, which might not be generalisable to the wider European population.
Dr Crowe said: "The main message from this analysis is that, in this study, people who consume more fruits and vegetables have lower risk of dying from IHD. However, we need to be cautious in our interpretation of the results because we are unsure whether the association between fruit and vegetable intake and risk of IHD is due to some other component of diet or lifestyle.
"If we could understand, by means of well-designed intervention studies, the biological mechanisms that could underlie the association between fruits and vegetables and IHD, this might help to determine whether or not the relation between fruit and vegetables with IHD risk is causal."
In an accompanying editorial, Professor Sir Michael Marmot, director of the University College London (UCL) International Institute for Society and Health, head of the UCL Department of Epidemiology and Public Health, and chairman of the Commission on Social Determinants of Health, writes that it is difficult to reach firm conclusions about causation from results that show a 22% lower risk of dying from IHD (an odds ration of 0.78) in people who eat eight portions of fruit and vegetables a day.
He continues: "Such an odds ratio is, however, of huge practical importance. Cardiovascular disease is the most common cause of death. A reduction of 22% is huge. But... this reduction in mortality comes with consumption of eight portions a day, or 640g. Such a high consumption was found in only 18% of the men and women in these eight cohorts. There would need to be big shift in dietary patterns to achieve this healthy consumption of eight portions a day. It is worth trying to move in that direction. Reductions in cancers of several sites, in blood pressure and stroke, would add to this reduction in fatal CHD. Moving to a diet that emphasises fruit and vegetables is of great importance to public health."
*The ten countries include: Denmark, France, Germany, Greece, Italy, The Netherlands, Norway, Spain, Sweden and the United Kingdom. For the Heart component of the study, data from France and Norway were excluded due to the small number of IHD deaths at the end of the follow-up period.
Antioxidant supplements may benefit couples who have difficulty conceiving naturally, according to a new systematic review published January 18 in The Cochrane Library. The review provides evidence from a small number of trials that suggest the partners of men who take antioxidants are more likely to become pregnant.
Male subfertility affects one in 20 men. Chemicals called reactive oxygen species (ROS) are said to cause damage to cells, and in particular sperm cells, which may result in lowered sperm counts and interfere with their ability to fertilise eggs. Antioxidants include natural and synthetic chemicals, including certain vitamins and minerals, which help to reduce the damage caused by ROS.
The review focused on 34 trials involving 2,876 couples undergoing assisted reproductive techniques such as in vitro fertilisation and sperm injections. Most men in the trials had low sperm counts or low sperm motility. The trials explored the use of many different types of oral antioxidants, including vitamin E, L-carnitine, zinc and magnesium.
Compared to controls, a couple was more likely to have a pregnancy or live birth if the man took antioxidants. However, these results are based on just 964 of the couples in the review for pregnancies and 214 couples for live births. Other trials tested the effects of antioxidants on sperm motility and concentration and showed mostly positive effects, although study group sizes were small.
"When trying to conceive as part of an assisted reproductive program, it may be advisable to encourage men to take oral antioxidant supplements to improve their partners' chances of becoming pregnant," said lead researcher Marian Showell, who works in Obstetrics and Gynaecology at the University of Auckland in Auckland, New Zealand. "However, these conclusions are currently based on limited evidence."
There were not enough data comparing different antioxidants to reach any conclusions about the relative effectiveness of supplements. "We need more head-to-comparisons to understand whether any one antioxidant is performing better than any other," said Showell.
According to research conducted at the Oregon National Primate Research Center at Oregon Health & Science University, the commonly held belief that oral contraceptives cause weight gain appears to be false. The results of the study are published online and will appear in next month's edition of the journal Human Reproduction.
"A simple Google search will reveal that contraceptives and the possibility that they may cause weight gain is a very highly debated topic," said Alison Edelman, M.D., a physician and researcher in the Department of Obstetrics and Gynecology at OHSU and lead author of the study.
"Issues surrounding weight are hard to study in humans, and the research thus far has been insufficient to demonstrate whether or not oral contraceptives cause weight gain or loss. But this is an extremely important question as concern about weight gain is one of the main reasons why women may avoid or discontinue birth control, which in turn places them at greater risk for an unplanned pregnancy."
To conduct their research, scientists and physicians studied a group of rhesus macaque monkeys at the OHSU Oregon National Primate Research Center for almost a year. Rhesus monkeys were used in this study because their reproductive system is nearly identical to humans. However, unlike human studies, more variables can be controlled and measured -- such as exact food intake -- to provide more meaningful data.
At the beginning of the study, half the animals were obese and half were normal weight. During the eight-month treatment period, animals received doses of oral contraceptives, adjusted to the weight of the animals so that it mimicked dosage in humans. Researchers tracked weight, food intake, activity levels, body fat and lean muscle mass. At the study's conclusion, the normal weight group remained weight stable whereas the obese group lost a significant amount of weight (8.5%) and percent of body fat (12%) due to an increase in basal metabolic rate. No changes were seen in food intake, activity or lean muscle mass for either group.
"This study suggests that worries about weight gain with pill use appear to be based more on fiction than on fact," said Judy Cameron, Ph.D., senior author of the paper and a researcher at the primate center.
"Additionally, there may be a differential affect depending on your starting weight -- heavier individuals who keep their diet stable may see a weight loss with pill use. Most likely, the reason why this belief continues to exist is that the weight gain that seems to occur with age is being attributed to these medications. We realize that research in nonhuman primates cannot entirely dismiss the connection between contraceptives and weight gain in humans, but it strongly suggests that women should not be as worried as they previously were.
Wednesday, January 19, 2011
Plenty of breaks, even if they are as little as one minute, seem to be good for people's hearts and their waistlines
It is becoming well accepted that, as well as too little exercise, too much sitting is bad for people's health. Now a new study has found that it is not just the length of time people spend sitting down that can make a difference, but also the number of breaks that they take while sitting at their desk or on their sofa. Plenty of breaks, even if they are as little as one minute, seem to be good for people's hearts and their waistlines.
The study, which is published online on January 12 in the European Heart Journal, is the first in a large, representative, multi-ethnic population to look at the links of the total amount of time spent sitting down and breaks in sedentary time, with various indicators of risk for heart disease, metabolic diseases such as diabetes, and inflammatory processes that can play a role in atherosclerosis (blocked arteries).
It found that prolonged periods of sedentary time, even in people who also spent some time in moderate-to-vigorous exercise, were associated with worse indicators of cardio-metabolic function and inflammation, such as larger waist circumferences, lower levels of HDL ("good") cholesterol, higher levels of C-reactive protein (an important marker of inflammation) and triglycerides (blood fats).
However, the study also found that, even in people who spent a long time sitting down, the more breaks they took during this time, the smaller their waists and the lower the levels of C-reactive protein.
There were some racial and ethnic differences. The most significant was that longer sedentary time had a marked adverse effect on waist circumference for non-Hispanic whites only, but made no difference to Mexican Americans and appeared to be beneficial for non-Hispanic blacks.
Dr Genevieve Healy, a research fellow at the School of Population Health, The University of Queensland, Australia, who led the study, said: "Overall, for length of sedentary time, the most clinically significant findings were for blood fats and markers of insulin resistance. For the number of breaks in sedentary time, the most significant differences were observed for waist circumference. The top 25% of people who took the most breaks had, on average, a 4.1cm smaller waist circumference than those in the lowest 25%."
Dr Healy and her colleagues analysed data from 4,757 people aged 20 and over, who took part in the US National Health and Nutrition Examination Survey between 2003 and 2006. The participants wore a small device called an accelerometer, which monitored the amount and intensity of walking or running activity. It was worn on the right hip during waking hours for seven days and it gave researchers information on sedentary time and breaks in sedentary time. Measurements were taken of waist circumference, blood pressure, cholesterol levels and C-reactive protein concentrations, and they also measured levels of triglycerides, plasma glucose and insulin in a sub-sample of participants who were fasting when attending a morning examination. The researchers accounted statistically for socio-demographic differences between study participants, their medical histories and their lifestyles (smoking, alcohol intake, diet).
The least amount of sedentary time was 1.8 hours per day, the most 21.2 hours per day; the least number of breaks over the full seven days was 99, and the most was 1,258.
Dr Healy said: "The benefits of regular participation in moderate-to-vigorous intensity exercise are well accepted scientifically and by the general public. However, the potential adverse health impact of prolonged sitting (which is something that we do on average for more than half of our day), is only just being realised. Our research highlights the importance of considering prolonged sedentary time as a distinct health risk behaviour that warrants explicit advice in future public health guidelines. In particular, the findings are likely to have implications for settings where prolonged sitting is widespread, such as in offices.
"Our research showed that even small changes, which could be as little as standing up for one minute, might help to lower this health risk. It is likely that regular breaks in prolonged sitting time could be readily incorporated into the working environment without any detrimental impact on productivity, although this still needs to be determined by further research. 'Stand up, move more, more often' could be used as a slogan to get this message across."
She said that existing occupational health and safety guidelines recommend regular changes in posture and a variety of work tasks, and that these would help to incorporate more breaks from sitting in the working day, and might lead to less sedentary time overall. Practical tips that might help to do this in an office-based workplace included:
* Standing up to take phone calls
* Walking to see a colleague rather than phoning or emailing
* Having standing meetings or encouraging regular breaks during meetings for people to stand up
* Going to a bathroom on a different level
* Centralising things such as rubbish bins and printers so that you need to walk to them
* Taking the stairs instead of the lift where possible.
Dr Healy said that the size of the differences in the various cardio-metabolic and inflammatory risk biomarkers between the top and bottom 25% of people in terms of their sedentary time was large enough to suggest that "in theory, population-wide reductions in sedentary time of between one to two hours a day could have a substantial impact on the prevention of cardiovascular disease."
She concluded: "Prolonged sedentary time is likely to increase with future technological and social innovations, and it is important to avoid prolonged periods of sitting and to move more throughout the day. Reducing and regularly breaking up sedentary time may be an important adjunct health message, alongside the well-established recommendation for regular participation in exercise. While further evidence of a causal nature is required, less sitting time would be unlikely to do harm. It would, at the very least, contribute to increased overall levels of daily energy expenditure and could help to prevent weight gain."
For postmenopausal women with osteopenia (low bone mineral density), practicing tai chi and/or taking green tea polyphenols appears to be safe. Further, practicing tai chi by itself or in combination with green tea polyphenol supplements may improve quality of life; however, taking green tea supplements by themselves has no significant improvement in quality of life. This is according to a recent NCCAM-funded study published in BMC Complementary and Alternative Medicine. Osteopenia may precede osteoporosis, a bone disease characterized by reduced bone strength that can lead to fractures—a significant cause of disability in older people.
Previous clinical studies have suggested that tai chi—a traditional Chinese practice involving physical movement, mental focus, and deep breathing—has beneficial effects on bone health. Likewise, animal research has indicated that green tea polyphenols (substances rich in antioxidants) also may have bone-protective effects. However, there is limited information on the long-term safety of green tea supplements in people as well as several reports concerning their adverse effects on liver and kidney function. To further build on this evidence and to evaluate the effect of tai chi in combination with green tea polyphenol supplements, NCCAM-funded researchers investigated the safety and impact on quality of life of these interventions in postmenopausal women with osteopenia. (This study is part of a larger research project that is investigating the effects of green tea polyphenols and tai chi on bone health in postmenopausal women with low bone mineral density. Results of other findings from the study—bone, inflammation, and stress parameters—will be published at a later date.)
Researchers from Texas Tech University randomly assigned 171 women to receive green tea polyphenols (500 mg daily); green tea polyphenols plus tai chi training; placebo pills (500 mg starch daily); or placebo pills plus tai chi training over a 24-week period. The tai chi training consisted of three 60-minute sessions per week. Researchers measured participants' depression (mood) and general health status, as well as liver and kidney function throughout the study. Participants in the tai chi groups reported significant beneficial effects in quality of life in terms of improving their emotional and mental health. The researchers found that green tea supplements did not significantly affect participants' liver enzymes or kidney serum levels and had no effect on quality of life.
The researchers noted that this is the first placebo-controlled, randomized study to evaluate the safety of long-term use of green tea supplements in postmenopausal women. Based on these findings, the researchers concluded that green tea polyphenols at a dose of 500 mg daily for 24 weeks, alone or in combination with tai chi, appears to be safe in postmenopausal women with low bone mineral density.
- Shen C-L, Chyu M-C, Pence BC, et al. Green tea polyphenols supplementation and tai chi exercise for postmenopausal osteopenic women: safety and quality of life report. BMC Complementary and Alternative Medicine. 2010;10(1):76. [Epub ahead of print]
Tuesday, January 18, 2011
Antioxidants are sold over the counter everywhere. They’re added to food, drink, and face cream. But according to Prof. Nava Dekel of the Weizmann Institute of Science’s Department of Biological Regulation, we still don’t have a complete understanding of how they act in our bodies. New research by Prof. Dekel and her team, recently published in the Proceedings of the National Academy of Sciences (PNAS), has revealed an unexpected possible side effect of antioxidants: they might cause fertility problems in females.
Common antioxidants include vitamins C and E. These work by eliminating molecules called reactive oxygen species that are produced naturally in the body. Stress can cause these chemically active molecules to be overproduced; in large amounts they damage cells indiscriminately. By neutralizing these potentially harmful substances, antioxidants may, theoretically, improve health and slow down the aging process.
But when Prof. Dekel and her research team, including her former and present PhD students Dr. Ketty Shkolnik and Ari Tadmor, applied antioxidants to the ovaries of female mice, the results were surprising: ovulation levels dropped precipitously. That is, very few eggs were released from the ovarian follicles to reach the site of fertilization, compared to those in untreated ovaries.
To understand what lies behind these initial findings, the team asked whether it is possible that the process of ovulation might rely on the very “harmful” substances destroyed by antioxidants – reactive oxygen species.
Further testing in mice showed that this is, indeed, the case. In one experiment, for instance, Prof. Dekel and her team treated some ovarian follicles with luteinizing hormone, which is the physiological trigger for ovulation, and others with hydrogen peroxide, which is a reactive oxygen species. The results showed hydrogen peroxide fully mimicked the effect of the ovulation-inducing hormone. This implies that reactive oxygen species that are produced in response to luteinizing hormone serve, in turn, as mediators for this physiological stimulus leading to ovulation.
Among other things, these results help fill in a picture that has begun to emerge in recent years of fertility and conception, in which it appears that these processes share a number of common mechanisms with inflammation. It makes sense, says Prof. Dekel, that substances which prevent inflammation in other parts of the body might also get in the way of normal ovulation, and so more caution should be taken when administering such substances.
Much of Prof. Dekel’s research has focused on fertility – her previous results are already helping some women become pregnant. Ironically, the new study has implications for those seeking the opposite effect. According to Prof. Dekel, “On the one hand, these findings could prove useful to women who are having trouble getting pregnant. On the other, further studies might show that certain antioxidants might be effective means of birth control that could be safer than today’s hormone-based prevention.”
Prof. Dekel and her team are now planning further studies to investigate the exact mechanics of this step in the fertility process: to find out just how, when, and where antioxidants affect the ovaries, and to examine their effect on mice when administered in either food or drink. In addition, they plan to collect data on the possible link between females taking antioxidant supplements and difficulty conceiving.
NSAID Receptor Responsible for Olive Oil’s ‘Cough’ and More
Combination of sensory and molecular approaches identify receptor sensitive to anti-inflammatory compounds
Scientists from the Monell Center and collaborators report that a receptor known as TRPA1 is activated by two structurally unrelated anti-inflammatory compounds. The first, oleocanthal, is a natural polyphenolic anti-inflammatory agent uniquely found in extra virgin olive oil; while the second, ibuprofen, is an over-the-counter non-steroidal anti-inflammatory drug (NSAID).
The researchers also demonstrate that the TRPA1 receptor is spatially localized to the back of the throat, which is exactly where the distinctive irritating sting from olive oil is felt. This unique sensation and the accompanying ‘cough’ are regarded among connoisseurs as indicators of high quality olive oil.
“We believe that the TRPA1 receptor elicits cough to protect the lungs from chemical insult, for example from toxins in the air,” said Paul A.S. Breslin, Ph.D., one of the corresponding authors and a sensory biologist at Monell.
In 2005, Monell researchers and collaborators announced the discovery that oleocanthal is a non-steroidal, anti-inflammatory agent that inhibits activity of cyclooxygenase (COX) enzymes, a pharmacological action shared by ibuprofen.
The finding was based on the sensory observation that olive oil irritates the back of the throat in a highly characteristic manner identical to that experienced with liquid ibuprofen.
At that time, the researchers also demonstrated that oleocanthal caused the irritating throat sting associated with extra virgin olive oils.
The current study, published in the Journal of Neuroscience, extends those findings by identifying TRPA1 as the receptor that is activated by both oleocanthal and ibuprofen. Further, the findings establish that oleocanthal causes the distinctive sting of olive oil through its activation of TRPA1. Similarly, activation of the same receptor produces ibuprofen’s irritating sensation.
The findings may provide novel insights into anti-inflammatory pharmacology. “This receptor may be used to identify other anti-inflammatory compounds that, like ibuprofen and oleocanthal, help prevent major lethal disease,” said Breslin.
“Additionally, since we know how to inhibit this receptor, it may be possible to develop liquid anti-inflammatory medicines that are less aversive. This would especially benefit children, who are unable to swallow pills.”
The study’s combination of sensory, chemical, and molecular approaches may lend insight into other aspects of inflammation and disease.
“Oleocanthal and ibuprofen are chemically unrelated, yet both are potent anti-inflammatory compounds that activate the TRPA1 receptor and cause sensory irritation,” said Monell behavioral biologist Gary K. Beauchamp, Ph.D., also a corresponding author. “This points to a possible mechanistic connection between sensory perception, receptor activation, and pharmacology. An understanding of this connection could someday lead to identification of new anti-inflammatory pathways.”
Future work also will explore several paradoxical associations that relate the sensory and health-promoting aspects of oleocanthal and ibuprofen. Lead author Catherine Peyrot des Gachons, Ph.D., a food scientist at Monell, points out that the two anti-inflammatories promote health while also causing irritation and pain. She comments, “These two facts seem antagonistic and excitingly mysterious from a scientific perspective.”
Beauchamp raises a related question, noting that humans have come to appreciate the ‘pain’ from oleocanthal in olive oil, as if there is an inner knowledge that it is advantageous. “How this happens remains a fascinating puzzle,” he says.
Does eating a big breakfast help weight loss or is it better to skip breakfast altogether? Available information is confusing but new research published in BioMed Central's open access journal Nutrition Journal clears a path through these apparently contradictory reports.
Dr Volker Schusdziarra, from the Else-Kröner-Fresenius Center of Nutritional Medicine, conducted a study on over 300 people who were asked to keep a journal of what they usually ate. Within the group sometimes people ate a big breakfast, sometimes small, and sometimes skipped it all together.
Schusdziarra said that "the results of the study showed that people ate the same at lunch and dinner, regardless of what they had for breakfast", this means that a big breakfast (on average 400kcal greater than a small breakfast) resulted in a total increase in calories eaten over the day of about 400kcal. The only difference seen was the skipping of a mid morning snack when someone ate a really big breakfast, however this was not enough to offset the extra calories they had already eaten.
The group addressed previous research, which suggests that eating a big breakfast reduces total calorie intake over the day, and showed that this data is misleading. This earlier research only looked at the ratio of breakfast calories to daily calories and in Schusdziarra's study this ratio seems to be most affected by people eating less during the day. In other words their breakfast was proportionally, but not absolutely, bigger. So it seems that there is no magic and that, unfortunately, in the fight for weight-loss, eating a large breakfast must be counteracted by eating substantially less during the rest of the day. In order to lose weight sensibly NHS guidelines suggest restricting calorie intake, cutting down on saturated fat and sugar, and eating 5-a-day fruit and veg.
1. This is the wrong time of the year (NFL playoffs, UConn basketball, snow, cold, early darkness) to find this out:
Spending too much leisure time in front of a TV or computer screen appears to dramatically increase the risk for heart disease and premature death from any cause. People who devote more than four hours to screen-based entertainment like watching TV, using the computer or playing video games, are more than twice as likely to have a major cardiac event that involves hospitalization, death or both.
Question - why would working in front of a computer, or reading for work or leisure be any different? If not I'm in big trouble year round. I am going to try to get up and move around more while I work, watch sports, and read.
2. Or maybe I should lift weights while watching TV ( I actually tried to do this for a while):
Resistance Training Benefits Cardiovascular Health
3. Perhaps I should just sit (or move around) in the darkness all evening:
According to a recent study exposure to electrical light between dusk and bedtime strongly suppresses melatonin levels and may impact physiologic processes regulated by melatonin signaling, such as sleepiness, thermoregulation, blood pressure and glucose homeostasis.
4. I went and ate some blueberries as soon as I read this:
Eating blueberries can guard against high blood pressure
5. I don't drink coffee, but probably should, but do drink a lot of green tea:
Coffee protects against diabetes
Regularly drinking green tea could protect against Alzheimer's and other forms of dementia
Nothing else new here, but it's a great summary:
Research indicates that tea strengthens the body’s immune system, reduces buildup of plaque on arterial walls, and aids in the control and prevention of diabetes.
Like tea, coffee is packed with polyphenols, and it actually has a higher content of antioxidants than green or black tea and other beverages such as fruit and vegetables juices. New research has suggested that coffee consumption can lower cardiovascular risks as well as lower the risk of developing type 2 diabetes by up to 50 percent. Coffee also appears to have a positive effect on neurological diseases with coffee consumption possibly reducing the risk of both Parkinson’s disease and Alzheimer’s disease.
6. I'm doing still not getting quite enough red wine ( and an occasional beer) but I'm doing better, and I take a resveratrol pill as well:
a. Alcohol Abstinence = Increased Risk of Cognitive Impairment
Both abstainers and subjects consuming large amounts of alcohol have a greater risk for cognitive impairment than light drinkers.
b. How resveratrol works
7. I've been repeatedly urged to get this shot by my pediatrician ( my daughter). I don't find the evidence all that overwhelming:
Shingles Vaccine Associated With 55 Percent Reduced Risk of Disease
8. And, of course more research on diet, (I'm doing much better choosing the right kinds of foods) exercise, ( I just joined a gym! -to get into shape for soccer) and Vitamin D. (I'm doing pretty well with supplements):
a. Mediterranean Diet Associated With Slower Rate of Cognitive Decline
New research suggests that eating a healthy diet rich in fruit and vegetables gives you a more healthy golden glow than the sun.
The face in the middle shows the woman's natural colour. The face on the left shows the effect of sun tanning, while the face on the right shows the effect of eating more carotenoids. Participants thought the carotenoid colour looked healthier.
a. Exercise Could Help Prevent, Treat Eating Disorders
b. Consistent exercise = lower risk of colon cancer death
a. Low Vitamin D = Increased Risk of Hip Fracture
b. Vitamin D deficiency could be linked to the development and severity of certain autoimmune lung diseases.
Friday, January 14, 2011
Exercise – it will cure what ails you, or at least some of the most common ailments.
Research conducted in the College of Health Sciences’ Department of Health, Leisure and Exercise Science at Appalachian State University has shown that resistance training has some similar effects as aerobic exercise in lowering a person’s blood pressure.
Dr. Scott Collier was the lead investigator of the study published in the October 2010 Journal of Strength and Conditioning Research. The study is part of the growing body of research being conducted at Appalachian on the effects of exercise, supplements and health.
Collier looked at changes that occurred to arteries and blood flow following 45 minutes of moderate intensity resistance exercise using machines like those typically found in fitness centers.
He found that the resistance training resulted in as much as a 20 percent decrease in a person’s blood pressure, which is as good as or better than the benefit of taking anti-hypertensive medication. “And exercise has no adverse side effects,” Collier said.
“Resistance exercise increases blood flow which reduces blood pressure,” he said. The findings are significant, he explained, because it shows that aerobic exercise isn’t the only way a person can improve their cardiovascular health.
“Aerobic exercise is the American Heart Association’s preferred exercise for decreasing cardiovascular risk,” Collier said. “However, there are a lot of people with orthopedic or obesity limitations who can’t walk or run long distances. For them, that type of exercise would be contraindicated.” he said.
He found that the beneficial effects of resistance training continued about 30 minutes after the exercise had ended and as long as 24 hours in individuals who trained for 30-45 minutes three times a week.
Collier said women who use resistance training to lower their blood pressure gain additional benefits. “Resistance training also helps protect against or treat osteoporosis,” he said. “Any exercise is good. But if you can’t do aerobic exercise, resistance exercise can help decrease blood pressure and increase metabolism as well as provide social and psychological benefits”.
Eating blueberries can guard against high blood pressure, according to new research by the University of East Anglia and Harvard University.
High blood pressure – or hypertension – is one of the major cardiovascular diseases worldwide. It leads to stroke and heart disease and costs more than $300 billion each year. Around a quarter of the adult population is affected globally – including 10 million people in the UK and one in three US adults.
Published next month in the American Journal of Clinical Nutrition, the new findings show that bioactive compounds in blueberries called anthocyanins offer protection against hypertension. Compared with those who do not eat blueberries, those eating at least one serving a week reduce their risk of developing the condition by 10 per cent.
Anthocyanins belong to the bioactive family of compounds called flavonoids and are found in high amounts in blackcurrants, raspberries, aubergines, blood orange juice and blueberries. Other flavonoids are found in many fruits, vegetables, grains and herbs. The flavonoids present in tea, fruit juice, red wine and dark chocolate are already known to reduce the risk of cardiovascular disease.
This is the first large study to investigate the effect of different flavonoids on hypertension.
The team of UEA and Harvard scientists studied 134,000 women and 47,000 men from the Harvard established cohorts, the Nurses’ Health Study and the Health Professionals Follow-up Study over a period of 14 years. None of the participants had hypertension at the start of the study. Subjects were asked to complete health questionnaires every two years and their dietary intake was assessed every four years. Incidence of newly diagnosed hypertension during the 14-year period was then related to consumption of various different flavonoids.
During the study, 35,000 participants developed hypertension. Dietary information identified tea as the main contributor of flavonoids, with apples, orange juice, blueberries, red wine, and strawberries also providing important amounts. When the researchers looked at the relation between individual subclasses of flavonoids and hypertension, they found that participants consuming the highest amounts of anthocyanins (found mainly in blueberries and strawberries in this US-based population) were eight per cent less likely to be diagnosed with hypertension than those consuming the lowest amounts. The effect was even stronger in participants under 60.
The effect was strongest for blueberry rather than strawberry consumption. Compared to people who ate no blueberries, those eating at least one serving of blueberries per week were 10 per cent less likely to become hypertensive.
“Our findings are exciting and suggest that an achievable dietary intake of anthocyanins may contribute to the prevention of hypertension,” said lead author Prof Aedin Cassidy of the Department of Nutrition at UEA’s Medical School.
“Anthocyanins are readily incorporated into the diet as they are present in many commonly consumed foods. Blueberries were the richest source in this particular study as they are frequently consumed in the US. Other rich sources of anthocyanins in the UK include blackcurrants, blood oranges, aubergines and raspberries.”
Thursday, January 13, 2011
For hundreds of years, ancient cultures have relied on tea for medicinal purposes, and modern science is now verifying why. Tea is an antioxidant-rich beverage containing more polyphenols than many fruits and vegetables. Besides being rich in compounds that combat cell-damaging oxidative stress, tea has a chemical makeup that includes enzymes, carbohydrates, protein, and lipids. Oxidative stress is a molecular imbalance that interferes with the body’s ability to detoxify harmful compounds leading to cellular damage and is associated with chronic health problems such as atherosclerosis, diabetes, dementia, and even cancer. Packed with compounds that protect cells from oxidative stress, tea has emerged as a natural dietary aid to lower the risk of these ailments. Research indicates that tea strengthens the body’s immune system, reduces buildup of plaque on arterial walls, and aids in the control and prevention of diabetes.
Like tea, coffee is packed with polyphenols, and it actually has a higher content of antioxidants than green or black tea and other beverages such as fruit and vegetables juices. New research has suggested that coffee consumption can lower cardiovascular risks as well as lower the risk of developing type 2 diabetes by up to 50 percent. Coffee also appears to have a positive effect on neurological diseases with coffee consumption possibly reducing the risk of both Parkinson’s disease and Alzheimer’s disease.
It is widely known that milk is an excellent source of protein, calcium, and vitamin D and it helps build teeth and bone mass during childhood and adolescence. Recent research findings detail the benefits of whole, low-fat, and chocolate milk when it comes to overall nutrition, bone density, weight loss, muscle-building and more. Other research indicates that when consumed after resistance training, both unflavored and chocolate-flavored versions of reduced-fat milk, improve muscle development, enhance strength, and increase fat loss.
Food Technology magazine is published by the Institute of Food Technologists. Read the full article.
Researchers discover molecular mechanism behind drink's prophylactic effect
Coffee, that morning elixir, may give us an early jump-start to the day, but numerous studies have shown that it also may be protective against type 2 diabetes. Yet no one has really understood why.
Now, researchers at UCLA have discovered a possible molecular mechanism behind coffee's protective effect. A protein called sex hormone–binding globulin (SHBG) regulates the biological activity of the body's sex hormones, testosterone and estrogen, which have long been thought to play a role in the development of type 2 diabetes. And coffee consumption, it turns out, increases plasma levels of SHBG.
Reporting with colleagues in the current edition of the journal Diabetes, first author Atsushi Goto, a UCLA doctoral student in epidemiology, and Dr. Simin Liu, a professor of epidemiology and medicine with joint appointments at the UCLA School of Public Health and the David Geffen School of Medicine at UCLA, show that women who drink at least four cups of coffee a day are less than half as likely to develop diabetes as non-coffee drinkers.
When the findings were adjusted for levels of SHBG, the researchers said, that protective effect disappeared.
The American Diabetes Association estimates that nearly 24 million children and adults in the U.S. — nearly 8 percent of the population — have diabetes. Type 2 diabetes is the most common form of the disease and accounts for about 90 to 95 percent of these cases.
Early studies have consistently shown that an "inverse association" exists between coffee consumption and risk for type 2 diabetes, Liu said. That is, the greater the consumption of coffee, the lesser the risk of diabetes. It was thought that coffee may improve the body's tolerance to glucose by increasing metabolism or improving its tolerance to insulin.
"But exactly how is elusive," said Liu, "although we now know that this protein, SHBG, is critical as an early target for assessing the risk and prevention of the onset of diabetes."
Earlier work by Liu and his colleagues published in the New England Journal of Medicine had identified two mutations in the gene coding for SHBG and their effect on the risk of developing type 2 diabetes; one increases risk while the other decreases it, depending on the levels of SHBG in the blood.
A large body of clinical studies has implicated the important role of sex hormones in the development of type 2 diabetes, and it's known that SHBG not only regulates the sex hormones that are biologically active but may also bind to receptors in a variety of cells, directly mediating the signaling of sex hormones.
"That genetic evidence significantly advanced the field," said Goto, "because it indicated that SHBG may indeed play a causal role in affecting risk for type 2 diabetes."
"It seems that SHBG in the blood does reflect a genetic susceptibility to developing type 2 diabetes," Liu said. "But we now further show that this protein can be influenced by dietary factors such as coffee intake in affecting diabetes risk — the lower the levels of SHBG, the greater the risk beyond any known diabetes risk factors."
For the study, the researchers identified 359 new diabetes cases matched by age and race with 359 apparently healthy controls selected from among nearly 40,000 women enrolled in the Women's Health Study, a large-scale cardiovascular trial originally designed to evaluate the benefits and risks of low-dose aspirin and vitamin E in the primary prevention of cardiovascular disease and cancer.
They found that women who drank four cups of caffeinated coffee each day had significantly higher levels of SHBG than did non-drinkers and were 56 percent less likely to develop diabetes than were non-drinkers. And those who also carried the protective copy of the SHBG gene appeared to benefit the most from coffee consumption.
When the investigators controlled for blood SHBG levels, the decrease in risk associated with coffee consumption was not significant. This suggests that it is SHBG that mediates the decrease in risk of developing type 2 diabetes, Liu said.
And there's bad news for decaf lovers. "Consumption of decaffeinated coffee was not significantly associated with SHBG levels, nor diabetes risk," Goto said. "So you probably have to go for the octane!"
New study shows indoor lighting has profound suppressive effect on the hormone melatonin
According to a recent study accepted for publication in The Endocrine Society's Journal of Clinical Endocrinology & Metabolism (JCEM), exposure to electrical light between dusk and bedtime strongly suppresses melatonin levels and may impact physiologic processes regulated by melatonin signaling, such as sleepiness, thermoregulation, blood pressure and glucose homeostasis.
Melatonin is a hormone produced at night by the pineal gland in the brain. In addition to its role in regulating the sleep-wake cycle, melatonin has been shown to lower blood pressure and body temperature and has also been explored as a treatment option for insomnia, hypertension and cancer. In modern society, people are routinely exposed to electrical lighting during evening hours to partake in work, recreational and social activities. This study sought to understand whether exposure to room light in the late evening may inhibit melatonin production.
"On a daily basis, millions of people choose to keep the lights on prior to bedtime and during the usual hours of sleep," said Joshua Gooley, PhD, of Brigham and Women's Hospital and Harvard Medical School in Boston, Mass. and lead author of the study. "Our study shows that this exposure to indoor light has a strong suppressive effect on the hormone melatonin. This could, in turn, have effects on sleep quality and the body's ability to regulate body temperature, blood pressure and glucose levels."
In this study, researchers evaluated 116 healthy volunteers aged 18-30 years who were exposed to room light or dim light in the eight hours preceding bedtime for five consecutive days. An intravenous catheter was inserted into the forearms of study participants for continuous collection of blood plasma every 30-60 minutes for melatonin measurements. Results showed exposure to room light before bedtime shortened melatonin duration by about 90 minutes when compared to dim light exposure. Furthermore, exposure to room light during the usual hours of sleep suppressed melatonin by greater than 50 percent.
"Given that chronic light suppression of melatonin has been hypothesized to increase relative risk for some types of cancer and that melatonin receptor genes have been linked to type 2 diabetes, our findings could have important health implications for shift workers who are exposed to indoor light at night over the course of many years," said Gooley. "Further research is still needed to both substantiate melatonin suppression as a significant risk factor for breast cancer and determine the mechanisms by which melatonin regulates glucose metabolism."
When treating an eating disorder, exercise is rarely considered therapeutic; it's more likely to be viewed as dangerous for patients already obsessed with their weight. But a new University of Florida study shows that the psychological benefits of exercise could be used as an intervention for -- or even a way to prevent -- eating disorders.
Despite the documented mental and physical benefits of exercise, health care practitioners have long assumed that people with eating disorders shouldn't be encouraged to burn calories through physical activity. While it's true that compulsive exercisers risk further harm, healthy exercise that's not compulsive could help people with eating disorders or people who are at risk for eating disorders, said Heather Hausenblas, a UF exercise psychologist who co-authored the study, published in the January issue of European Eating Disorders Review.
"When it comes to eating disorders, exercise has always been seen as a negative because people use it as a way to control their weight. But for most people, exercise is a very positive thing," Hausenblas said. "Our results show it's not necessarily bad for people with disordered eating to engage in exercise. The effects on self-esteem, depression, mood and body image can reduce the risk of eating pathologies."
In the study, co-authored by Brian Cook, an exercise psychologist at the University of Kentucky, Peter Giacobbi, an assistant professor at the University of Arizona, and former UF doctoral student Daniel Tuccitto, Hausenblas and her colleagues surveyed 539 normal-weight students, most of whom were not at risk for eating disorders. They evaluated the students' drive to be thin, along with their exercise habits and risk for exercise dependence, and used statistical models to find potential relationships. She found that, more than its physical benefits, the psychological effects of exercise could help prevent and treat eating disorders.
The study's findings could have far-reaching impact, said Danielle Symons Downs, director of the Exercise Psychology Laboratory at The Pennsylvania State University.
"The public health implications of this study are important," she said. "This research is important for understanding the complex interactions between exercise behavior and eating pathology, and it can assist clinicians with better understanding how to intervene with and treat eating pathology."
Beyond offering an affordable treatment to address the needs of people with eating disorders, exercise therapies also could help relieve the burden of such diseases on the health-care system, Hausenblas said. "If a patient is extremely underweight, you're not going to have them exercising two or three hours a day. But once they're at a stable level, exercise could have a big positive effect," she said. Hausenblas hopes to launch another study that would follow at-risk individuals over a period of several months to see if exercise impacts their symptoms.
"We'd like to assess them over time, and we hope to see their risk factors go down," she said.
I used to be a sun worshiper - 1:00 p.m. (Daylight Savings Time) on June 21st was a holy moment each year - the time when the sun was closest to the earth. I got lots of tans, but rarely burned. It all added up, however. In recent years, I have had two skin cancers removed in operations, and many pre-cancerous growths burned off. I now am checked by a dermatologist every 6 months - I highly recommend it for all my readers.
Here are some statistics for skin cancers in Connecticut.
A 2004 survey found that 43.1% of white adults in Connecticut had at least one sunburn in the past year—an increase from 33.3% in 1999. Sunburns are a significant risk factor for the development of skin cancer.
■■ New Cases of Melanoma. The rate of new melanoma diagnoses—responsible for
75% of all skin cancer deaths—was 31% higher in Connecticut than the national
average from 2001-2005 and was the 8th highest in the U.S.9,10 An estimated 1,060
state residents were diagnosed with melanoma in 2008.
■■ New London County has the highest rate of melanoma diagnoses in the state,
79% above the national average.
■■ Deaths from Melanoma. Approximately 110 people in Connecticut die of melanoma
every year.11 Connecticut had the 17th highest melanoma death rate nationally from
2001-2005—7.4% higher than the U.S. average.
■■ Tolland County has the highest melanoma death rate in the state, 30% higher
than the national average.
Wednesday, January 12, 2011
Kaiser Permanente Research Strengthens National Recommendations
Receiving the herpes zoster vaccine was associated with a 55 percent reduced risk of developing shingles, according to a Kaiser Permanente study of 300,000 people that appears in the current issue of the Journal of the American Medical Association.
This retrospective study observed the outcomes of the effectiveness of the herpes zoster vaccine in a large, diverse population of men and women ages 60 years and older. Researchers found a significant reduced risk of shingles across all sub-groups -- those who are healthy as well as those with chronic conditions including diabetes or heart, lung or kidney diseases.
These study findings differ from the clinical trial of the vaccine, which observed its effectiveness on 38,000 participants 60 years of age and older and found it less effective for people older than 75. This new study found a 55 percent reduced risk of shingles among both adults 60 years and older, as well as adults 75 years and older who received the vaccine.
These findings support Centers for Disease Control and Prevention recommendations to offer the vaccine to eligible patients of all ages, including those over 75. Researchers note that additional examination of the vaccine's effect in the oldest group should continue. The herpes zoster vaccine was licensed in 2006, but uptake in the United States remains low: about 10 percent in 2009 in adults 60 years and older.
"Our study shows the vaccine has the potential to prevent tens of thousands of cases of shingles, a painful, lingering disease," said study lead author Hung Fu Tseng, PhD, MPH, a research scientist with the Kaiser Permanente Department of Research & Evaluation in Pasadena, Calif. "We suggest clinicians follow the CDC's recommendations to talk to their patients about the option of vaccination against this serious condition."
There are more than 1 million episodes of shingles every year in the United States. Shingles is a painful condition that can last months or years and can seriously impact quality of life. Shingles is caused by the dormant chickenpox virus, which stays in the body after a person has recovered from chickenpox. The virus can reactivate and replicate and cause shingles and damage to the nerve system. The elderly are especially vulnerable because as we age, our immunity against the virus that causes shingles declines.
"The risk of developing shingles during a lifetime is about 30 percent. It is therefore reassuring to confirm results of the original clinical trial that herpes zoster vaccine is effective at preventing this painful disease," said study co-author Rafael Harpaz, MD, MPH, an epidemiologist with the Centers for Disease Control and Prevention's National Center for Immunization and Respiratory Diseases. "Although that trial was well done, one cannot be sure a vaccine works outside a research setting until you evaluate it in routine medical practices. In addition, our study also provided new information that the vaccine worked to prevent shingles involving the eye, which can result in very serious complications."
Researchers conducted a retrospective observational study that looked at 75,761 vaccinated and 227,283 unvaccinated male and female members of Kaiser Permanente in Southern California from 2007 to 2009, using electronic health records to compare the incidence of shingles of the vaccinated and unvaccinated populations. Results remained after taking into account differences in sex, race, chronic diseases, and prior utilization.
This is the latest in a series of published Kaiser Permanente studies undertaken to better understand vaccine effectiveness and safety. Dr. Tseng published another study in JAMA that found the pneumococcal pneumonia vaccination is not associated with a reduced risk of heart attacks or strokes. Another Kaiser Permanente study found the combination vaccine for measles, mumps, rubella and chickenpox (MMRV) is associated with double the risk of febrile seizures for 1- to 2-year-old children compared to same-day administration of the separate vaccine for MMR (measles, mumps, rubella) and the varicella (V) vaccine for chickenpox. Other recent published Kaiser Permanente studies found children of parents who refuse vaccines are nine times more likely to get chickenpox and 23 times more likely to get whooping cough compared to fully immunized children. A study published last year found that herpes zoster, also known as shingles, is very rare among children who have been vaccinated against chickenpox.
Tuesday, January 11, 2011
New research suggests eating vegetables gives you a healthy tan. The study, led by Dr Ian Stephen at The University of Nottingham, showed that eating a healthy diet rich in fruit and vegetables gives you a more healthy golden glow than the sun.
The face in the middle shows the woman's natural colour. The face on the left shows the effect of sun tanning, while the face on the right shows the effect of eating more carotenoids. Participants thought the carotenoid colour looked healthier.
The research, which showed that instead of heading for the sun the best way to look good is to munch on carrots and tomatoes, has been published in the Journal Evolution and Human Behaviour.
Dr Ian Stephen, from the School of Psychology, University of Nottingham, Malaysia Campus, led the research as part of his PhD at the University of St Andrews and Bristol University. He said: “Most people think the best way to improve skin colour is to get a suntan, but our research shows that eating lots of fruit and vegetables is actually more effective.
Dr Stephen and his team in the Perception Lab found that people who eat more portions of fruit and vegetables per day have a more golden skin colour, thanks to substances called carotenoids. Carotenoids are antioxidants that help soak up damaging compounds produced by the stresses and strains of everyday living, especially when the body is combating disease. Responsible for the red colouring in fruit and vegetables such as carrots and tomatoes, carotenoids are important for our immune and reproductive systems.
Dr Stephen said: “We found that, given the choice between skin colour caused by suntan and skin colour caused by carotenoids, people preferred the carotenoid skin colour, so if you want a healthier and more attractive skin colour, you are better off eating a healthy diet with plenty of fruit and vegetables than lying in the sun.”
Dr Stephen suggests that the study is important because evolution would favour individuals who choose to form alliances or mate with healthier individuals over unhealthy individuals.
Professor David Perrett, who heads the Perception Lab, said: “This is something we share with many other species. For example, the bright yellow beaks and feathers of many birds can be thought of as adverts showing how healthy a male bird is. What’s more, females of these species prefer to mate with brighter, more coloured males. But this is the first study in which this has been demonstrated in humans.”
While this study describes work in Caucasian faces, the paper also describes a study that suggests the effect may exist cross culturally, since similar preferences for skin yellowness were found in an African population.
A study in New Delhi India has revealed high rates of vitamin D deficiency among hip fracture patients, confirming the conclusions of similar international studies which point to vitamin D deficiency as a risk factor for hip fracture.
A group of 90 hip fracture patients was compared to a matched control group of similar age, sex and co-morbidity. Of the patients who had suffered hip fractures, 76.7% were shown to be vitamin D deficient as measured by serum 25(OH)D levels of less than 20 ng/ml. In addition, 68.9% had elevated PTH levels. In comparison, only 32.3% of the controls had vitamin D deficiency and 42.2% had elevated PTH levels (secondary hyperparathyroidism).
Vitamin D deficiency has been linked to the pathogenesis of osteoporosis and is increasingly thought to play a role in muscle strength, certain cancers, multiple sclerosis and diabetes. Vitamin D levels are very low in the Indian population in all age groups, and could be explained by skin pigmentation, traditional clothing and the avoidance of sunlight.
So does heavy drinking
Previous research regarding the association between alcohol consumption and dementia or cognitive impairment in later life suggests that mild to moderate alcohol consumption might be protective of dementia. However, most of the research has been conducted on subjects already rather elderly at the start of the follow-up.
A new study published in the December issue of the Journal of Alzheimer's Disease addresses this problem with a follow-up of more than two decades.
The study, conducted at the University of Turku, University of Helsinki and National Institute for Health and Welfare in Finland based on subjects from the Finnish Twin Cohort, shows that midlife alcohol consumption is related to the risk of dementia assessed some 20 years later. The study indicates that both abstainers and subjects consuming large amounts of alcohol have a greater risk for cognitive impairment than light drinkers.
"Our finding is significant as the changes typical of Alzheimer's disease -- the most common dementia syndrome -- are thought to start appearing two to three decades before clinical manifestation and therefore identification of early risk factors is imperative," states Jyri Virta, researcher at University of Turku, Finland.
In addition to total alcohol consumption, the authors were able to assess the effects of different drinking patterns. The study suggests that drinking large amounts of alcohol (defined as a bottle of wine or the equivalent) at a single occasion at least monthly is an independent risk factor for cognitive impairment. Such binge drinking doubles the risk of cognitive impairment even when total alcohol consumption was statistically controlled for.
Similarly, passing out because of heavy drinking on one occasion was also found to increase the development of subsequent cognitive impairment. Thus, it is not only the amount of alcohol, but also the pattern by which alcohol is consumed that affects the risk of cognitive impairment. The published study is among the first to report these effects.
Monday, January 10, 2011
Spending too much leisure time in front of a TV or computer screen appears to dramatically increase the risk for heart disease and premature death from any cause, perhaps regardless of how much exercise one gets, according to a new study published in the January 18, 2011, issue of the Journal of the American College of Cardiology. Data show that compared to people who spend less than two hours each day on screen-based entertainment like watching TV, using the computer or playing video games, those who devote more than four hours to these activities are more than twice as likely to have a major cardiac event that involves hospitalization, death or both.
The study – the first to examine the association between screen time and non-fatal as well as fatal cardiovascular events – also suggests metabolic factors and inflammation may partly explain the link between prolonged sitting and the risks to heart health.
"People who spend excessive amounts of time in front of a screen - primarily watching TV - are more likely to die of any cause and suffer heart-related problems," said Emmanuel Stamatakis, PhD, MSc, Department of Epidemiology and Public Health, University College London, United Kingdom. "Our analysis suggests that two or more hours of screen time each day may place someone at greater risk for a cardiac event."
In fact, compared with those spending less than two hours a day on screen-based entertainment, there was a 48% increased risk of all-cause mortality in those spending four or more hours a day and an approximately 125% increase in risk of cardiovascular events in those spending two or more hours a day. These associations were independent of traditional risk factors such as smoking, hypertension, BMI, social class, as well as exercise.
The findings have prompted authors to advocate for public health guidelines that expressly address recreational sitting (defined as during non-work hours), especially as a majority of working age adults spend long periods being inactive while commuting or being slouched over a desk or computer.
"It is all a matter of habit. Many of us have learned to go back home, turn the TV set on and sit down for several hours – it's convenient and easy to do. But doing so is bad for the heart and our health in general," said Dr. Stamatakis. "And according to what we know so far, these health risks may not be mitigated by exercise, a finding that underscores the urgent need for public health recommendations to include guidelines for limiting recreational sitting and other sedentary behaviors, in addition to improving physical activity."
Biological mediators also appear to play a role. Data indicate that one fourth of the association between screen time and cardiovascular events was explained collectively by C-reactive protein (CRP), body mass index, and high-density lipoprotein cholesterol suggesting that inflammation and deregulation of lipids may be one pathway through which prolonged sitting increases the risk for cardiovascular events. CRP, a well-established marker of low-grade inflammation, was approximately two times higher in people spending more than four hours of screen time per day compared to those spending less than two hours a day.
Dr. Stamatakis says the next step will be to try to uncover what prolonged sitting does to the human body in the short- and long-term, whether and how exercise can mitigate these consequences, and how to alter lifestyles to reduce sitting and increase movement and exercise.
The present study included 4,512 adults who were respondents of the 2003 Scottish Health Survey, a representative, household-based survey. A total of 325 all-cause deaths and 215 cardiac events occurred during an average of 4.3 years of follow up.
Measurement of "screen time" included self-reported TV/DVD watching, video gaming, as well as leisure-time computer use. Authors also included multiple measures to rule out the possibility that ill people spend more time in front of the screen as opposed to other way around. Authors excluded those who reported a previous cardiovascular event (before baseline) and those who died during the first two years of follow up just in case their underlying disease might have forced them to stay indoors and watch TV more often. Dr. Stamatakis and his team also adjusted analyses for indicators of poor health (e.g., diabetes, hypertension).
This confirms an earlier study, published last January:
Every hour spent sitting idle in front of the television raises the risk of premature death from heart disease by 18 percent, an Australian study found.
Researchers tracked the TV-viewing habits of 8,800 adults and followed them for six years. They found those who spent four hours daily in front of the tube had an 80 percent greater risk of dying from cardiovascular disease than those who watched the box for less than two hours. The association was independent of risks such as smoking, obesity and unhealthy diet.
Prolonged inactivity, which can raise blood-sugar and cholesterol levels, is to blame for the health effects, not the appliance itself, said David Dunstan, a study author and researcher at Baker IDI Heart & Diabetes Institute in Melbourne. The finding, published today in the medical journal Circulation, supports studies from the Rochester, Minnesota-based Mayo Clinic showing that watching too much television is one of the biggest contributors to a sedentary lifestyle and weight gain.
“Too much sitting is bad for health,” said Dunstan, a professor of health sciences. “Avoid sitting for prolonged periods and keep in mind to move more, more often.”
Australians and Britons watch television for an average of three hours a day. In the U.S., where two-thirds of all adults are overweight or obese, viewing time is as much as eight hours, Dunstan said.