Tuesday, June 28, 2016
Consumption of omega-3s linked to lower risk of fatal heart disease
Blood levels of seafood and plant-based omega-3 fatty acids are associated with a lower risk of dying from heart attacks, according to a new epidemiological study, published today in JAMA Internal Medicine, led by Liana C. Del Gobbo, Ph.D., a postdoctoral research fellow in the division of cardiovascular medicine at Stanford University School of Medicine and senior author Dariush Mozaffarian, M.D., Dr.P.H., dean of the Friedman School of Nutrition Science and Policy at Tufts University in Boston.
Researchers from around the world joined together to form the Fatty acids and Outcomes Research Consortium (FORCE). By pooling findings from diverse large studies that had measured blood or tissue levels of omega-3 fatty acids, they evaluated relationships with heart disease events over time. Each study performed new standardized, individual-level analyses. Findings were then centrally pooled in a meta-analysis.
A total of 19 studies were involved from 16 countries and including 45,637 participants. Of these, 7,973 people developed a first heart attack over time, including 2,781 deaths and 7,157 nonfatal heart attacks.
Overall, both plant-based and seafood-based omega-3s were associated with about a 10 percent lower risk of fatal heart attacksper standard deviation. People with the highest blood levels of omega-3s had about a 25 percent lower risk of fatal heart attack, compared to people with the lowest levels. In contrast, these fatty acids biomarkers were generally not associated with a risk of nonfatal heart attacks, suggesting a more specific mechanism for benefits of omega-3s related to death.
"These new results, including many studies which previously had not reported their findings, provide the most comprehensive picture to-date of how omega-3s may influence heart disease," said Del Gobbo, who conducted this study as part of her postdoctoral work with Mozaffarian. "Across these diverse studies, findings were also consistent by age, sex, race, presence or absence of diabetes, and use of aspirin or cholesterol-lowering medications."
"At a time when some but not other trials of fish oil supplementation have shown benefits, there is uncertainty about cardiovascular effects of omega-3s," said Mozaffarian. "Our results lend support to the importance of fish and omega-3 consumption as part of a healthy diet."
Fish is the major food source of omega-3 fatty acids, including eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA). According to the U.S. Department of Agriculture's National Nutrient Database, fatty fish such as salmon, trout, anchovies, sardines, and herring contain the highest amounts of omega-3 fatty acids, although all fish contain some levels. In addition to omega-3 fatty acids, fish provide specific proteins, vitamin D, selenium, and other minerals and elements. Alpha-linolenic acid (ALA) is the plant-based omega-3 fatty acid found in walnuts, flaxseed oil, and canola oil and some other seed and nuts and their oils.
"Most prior studies of dietary fats have relied on self-reported estimates of intake," said Mozaffarian. "This new global consortium provides an unprecedented opportunity to understand how blood biomarkers of many different fats and fatty acids relate to diverse health outcomes, and many additional investigations are in progress."
This study is part of the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) Fatty acids and Outcomes Research Consortium (FORCE). There are 47 additional authors on the study.
This work was supported by awards from the National Heart, Lung, and Blood Institute, the National Human Genome Research Institute, the National Institutes of Health Roadmap for Medical Research, the National Institute of Neurological Disorders and Stroke, and the National Institute of Aging, all of the National Institutes of Health and numerous other funders including ones in Europe, Asia, and Australia. Please see the study for a full list of authors, funding sources, and conflicts of interest disclosure.
No association between 'bad cholesterol' and elderly deaths
A University of South Florida professor and an international team of experts have found that older people with high levels of a certain type of cholesterol, known as low-density lipoprotein (LDL-C), live as long, and often longer, than their peers with low levels of this same cholesterol.
The findings, which came after analyzing past studies involving more than 68,000 participants over 60 years of age, call into question the "cholesterol hypothesis," which previously suggested people with high cholesterol are more at risk of dying and would need statin drugs to lower their cholesterol.
Appearing online this month in the open access version of the British Medical Journal, the research team's analysis represents the first review of a large group of prior studies on this issue.
"We have known for decades that high total cholesterol becomes a much weaker risk for cardiovascular disease with advancing age," said Diamond. "In this analysis, we focused on the so-called "bad cholesterol" which has been blamed for contributing to heart disease."
According to the authors, either a lack of association or an inverse relationship between LDL-C and cardiovascular deaths was present in each of the studies they evaluated. Subsequently, the research team called for a reevaluation of the need for drugs, such as statins, which are aimed at reducing LDL-C as a step to prevent cardiovascular diseases.
"We found that several studies reported not only a lack of association between low LDL-C, but most people in these studies exhibited an inverse relationship, which means that higher LDL-C among the elderly is often associated with longer life," said Diamond.
Diamond also points out the research that suggests that high cholesterol may be protective against diseases which are common in the elderly. For example, high levels of cholesterol are associated with a lower rate of neurological disorders, such as Parkinson's disease and Alzheimer's disease. Other studies have suggested that high LDL-C may protect against some often fatal diseases, such as cancer and infectious diseases, and that having low LDL-C may increase one's susceptibility to these diseases.
"Our results pose several relevant questions for future," said study leader and co-author health researcher Dr. Uffe Ravnskov. "For example, why is total cholesterol a factor for cardiovascular disease for young and middle-age people, but not for the elderly? Why do a substantial number of elderly people with high LDL-C live longer than elderly people with low LDL-C?"
Diamond and colleagues have published a number of studies relating to the use and possible misuse of statins for treating cholesterol. Those studies, including their recent paper published in the medical journal Expert Review of Clinical Pharmacology, which demonstrated that the benefits of taking statins have been exaggerated and are misleading.
"Our findings provide a contradiction to the cholesterol hypothesis," concluded Diamond. "That hypothesis predicts that cardiovascular disease starts in middle age as a result of high LDL-C cholesterol, worsens with aging, and eventually leads to death from cardiovascular disease. We did not find that trend. If LDL-C is accumulating in arteries over a lifetime to cause heart disease, then why is it that elderly people with the highest LDL-C live the longest? Since people over the age of 60 with high LDL-C live the longest, why should we lower it?"
Thursday, June 23, 2016
Blueberries lesser known health benefits
Consumers know some of the benefits blueberries provide, but they're less aware of the advantages of reverting aging, improving vision and memory, a new University of Florida study shows.
Shuyang Qu, a doctoral student in agricultural education and
communication at the University of Florida Institute of Food and
Agricultural Sciences, led the study.
Qu and her colleagues wanted to determine how much consumers know about blueberry health benefits and see if there's a knowledge gap with blueberry health benefits among demographic groups. Using their findings, they will identify promotional opportunities for Florida blueberries.
Researchers surveyed more than 2,000 people in 31 states -- mostly on the East Coast and in the Midwest -- to see what they know about the health benefits of blueberries. Most were aware of the benefits of blueberries in warding off cancer and lowering the risk of heart disease. The UF/IFAS study also found that low-income populations tend to know less about blueberry health benefits.
"People being more familiar with blueberries as deterrents for cancer and heart disease may be related to the high general awareness of these two diseases," Qu said. "The fact that cancer and heart diseases are the leading causes of death in America may have led to more personal research related to preventing the diseases, leading to the respondents being exposed to these findings more than other benefits."
To help promote blueberries' health benefits, Qu and her colleagues suggest holding events during blueberry season, such as tastings or u-picks to draw consumers to the crop while providing a vehicle for information about blueberry health benefits.
Qu and her colleagues wanted to determine how much consumers know about blueberry health benefits and see if there's a knowledge gap with blueberry health benefits among demographic groups. Using their findings, they will identify promotional opportunities for Florida blueberries.
Researchers surveyed more than 2,000 people in 31 states -- mostly on the East Coast and in the Midwest -- to see what they know about the health benefits of blueberries. Most were aware of the benefits of blueberries in warding off cancer and lowering the risk of heart disease. The UF/IFAS study also found that low-income populations tend to know less about blueberry health benefits.
"People being more familiar with blueberries as deterrents for cancer and heart disease may be related to the high general awareness of these two diseases," Qu said. "The fact that cancer and heart diseases are the leading causes of death in America may have led to more personal research related to preventing the diseases, leading to the respondents being exposed to these findings more than other benefits."
To help promote blueberries' health benefits, Qu and her colleagues suggest holding events during blueberry season, such as tastings or u-picks to draw consumers to the crop while providing a vehicle for information about blueberry health benefits.
Is 'when we eat' as important as 'what we eat'?
In a review of research on the effect of meal patterns on health, the few studies available suggest that eating irregularly is linked to a higher risk of metabolic syndrome (high blood pressure, type 2 diabetes and obesity). The limited evidence highlights the need for larger scale studies to better understand the impact of chrono-nutrition on public health, argue the authors of two new papers, particularly with the rise in shift workers and 'social jetlag' where many of us live by social clocks rather than our internal body clocks.
Our current lifestyle has become demanding and more irregular. Food consumption patterns have changed markedly over the past decades: more meals are skipped, consumed outside the family home, on-the-go, later in the day, and more irregularly. Two papers published in the Proceedings of the Nutrition Society explore the implications for health from different eating habits, reviewing the evidence from a number of dietary studies as well as global differences in eating habits.
Eating inconsistently may affect our internal body clock or 'circadian rhythms' which typically follow a 24-hour cycle. Many nutritionally related metabolic processes in the body follow a circadian pattern such as appetite, digestion and the metabolism of fat, cholesterol and glucose. Food intake can influence our internal clocks, particularly in organs such as the liver and intestine, whilst our central clock is also regulated by the dark/light cycle which in turn can affect food intake. Chrono-nutrition involves studying the impact of nutrition on metabolic processes and how these may be influenced by and also alter circadian patterns through nutrient intake (ir)regularity, frequency and clock time.
A number of studies have shown that people working shifts have an increased risk of a number of diseases including cancer, cardiovascular disease and metabolic syndrome. For shift work, changes in dietary patterns are therefore an important aspect to consider when investigating its effects on health.
Social jetlag is estimated to affect more than 80% of the general population in central Europe, especially people living in urban areas. This discrepancy between our internal body clock and social clock has been linked to a greater risk of diseases like obesity and metabolic syndrome, whilst shorter periods of sleep have been linked to weight gain.
Consuming small but frequent meals to regulate appetite and weight is a concept that has been adopted in many fad diets, yet some studies have shown that a greater number of daily meals has been linked to a greater risk of obesity and thus one could argue that we should consume fewer meals per day, write the authors. However, without a reduced calorie intake, fewer meals are unlikely to bring major health benefits.
Moreover, when studying the impact of irregular meal patterns, it is also important to consider what people eat; some studies have found a link between how regularly people eat and what they choose to eat, for example with poorer food choices linked to breakfast skipping.
Along with studying the impact of what and when we eat, we should also consider 'with whom we eat', say the authors, pointing to evidence that regular family meals contribute to healthy eating habits in children and adolescents.
Globally, eating patterns vary widely according to the studies reviewed by the authors. The fact that lunch is the most important meal of the day is characteristic of France and the Mediterranean region, and reflects beliefs of the importance of pleasurable and social eating. Consequently, the French tend to eat together as a household more regularly and to follow a regular meal pattern of three meals a day. By contrast, in central England, drivers such as individual preferences and convenience dictate food choices, which translates to greater consumption of ready-prepared and take-away meals, more meal skipping and calorie-dense snack foods such as crisps.
In the UK and US, the proportion of energy intake increases gradually across the day, with breakfast providing the lowest proportion of energy and dinner the greatest. A shift towards greater energy intake at the evening meal has been reported in France in recent decades due to changing working patterns, although French eating patterns are not yet on par with those observed in England.
A recent clinical trial showed greater weight loss and improved blood sugar levels in overweight and obese women who ate more calories in the morning than in the evening. Further studies point to the importance of the ratio of evening-to-morning energy intake, and that evening intake may affect BMI differently based on whether people are regular or irregular consumers of breakfast.
Most national dietary guidelines focus on 'what' you should eat in terms of food and nutrients, with only a few also providing recommendations on 'when' you should eat over the course of a day. As such, further research is needed to shape future dietary guidelines, conclude the authors.
Dr Gerda Pot, Visiting Lecturer in the Diabetes and Nutritional Sciences Division at King's College London says: "There seems to be some truth in the saying 'Eat breakfast like a king, lunch like a prince and dinner like a pauper', however, this warrants further investigation."
"Whilst we have a much better understanding today of what we should be eating, we are still left with the question as to which meal should provide us with the most energy. Although the evidence suggests that eating more calories later in the evening is associated with obesity, we are still far from understanding whether our energy intake should be distributed equally across the day or whether breakfast should contribute the greatest proportion of energy, followed by lunch and dinner."
The authors of the two papers in the Proceedings of the Nutrition Society are from King's College London, Newcastle University, University of Surrey and Nestlé Research Centre.
Omega-3 supplementation: Patients spent an average of 2.4 fewer days in hospital
A new meta-analysis published in Clinical Nutrition found that cardiac surgery patients who received omega-3 polyunsaturated fatty acids (compared to placebo) in advance of surgery experienced reduced postoperative cardiac arrhythmias and significantly reduced the length of hospital stay by up to 2.4 days. The results are based on 11 RCT's with 1038 patients.
"Omega-3s are well known for their benefits on cardiovascular health, including a reduced risk of arrhythmias and reduced mortality in patients with recent myocardial infarction or cardiac failure," said co-author Dr. Pascal L. Langlois from the Department of Anesthesiology and Reanimation, Faculty of Medicine and Health Sciences at Sherbrooke University. "Furthermore, they exhibit interesting anti-inflammatory properties and modulate the immune system."
This study implies a reduction in hospital utilization and overall healthcare costs, and supports an existing body of research demonstrating the heart health benefits of omega-3s.
The reduced length of hospital stay in this study was likely associated with the tendency of the omega-3 group to experience a reduction in postoperative atrial fibrillation, according to the authors. The exact mechanism associated with this benefit is unknown, but it is widely believed to be due to the omega-3s' anti-inflammatory and anti-arrhythmic properties.
Leisure activities may reduce post-surgical delirium among older adults
Delirium, or the medical term for experiencing sudden confusion, is upsetting for both older adults and their families. In fact, it is one of the most common complications older adults face after surgery (a time often referred to as the "post-operative" period). Researchers believe that older adults who have higher levels of "cognitive reserve" may have a better chance for reducing their chances of developing dementia--which theoretically could reduce the risks for developing delirium.
One way to understand cognitive reserve is to think of your brain as a muscle. When you exercise a muscle, you strengthen it. Activities such as reading, playing computer games, singing, emailing and even knitting may act as "exercise" for your brain, "strengthening" it in a way that could help prevent dementia and delirium. A group of researchers from Albert Einstein College of Medicine in the Bronx, NY, examined whether certain leisure activities known to reduce dementia risks could also reduce the risk of post-surgical delirium. They published their findings in the June issue of the Journal of the American Geriatrics Society.
The researchers examined a group of 142 older adults who were scheduled for elective knee, hip, or spinal surgery. They determined whether or not the people participated in leisure activities such as reading books or newspapers, knitting, emailing, playing cards or other games, working on crossword puzzles, or joining in group meetings.
Of those involved in the study, 32 percent developed post-operative delirium. Those who were diagnosed with delirium had participated in fewer leisure activities before surgery compared with people who didn't experience delirium.
Out of all the activities, reading books, using email, and playing computer games reduced the risk of delirium. Playing computer games and singing were the only two activities that predicted lower severity of delirium.
The researchers reported that each additional day of participation in a leisure activity reduced post-operative delirium by 8 percent. According to the researchers, maintaining leisure activities later in life could be an important way to lessen the chances of developing delirium following surgery. This is important, since delirium increases an older adult's risk for functional decline, dementia, and even mortality. What's more, people with severe post-operative delirium are at greater risk for being institutionalized and for dying.
Wednesday, June 22, 2016
Healthy aging benefits may be associated with walnut consumption
A new study published in the Journal of Nutrition suggests that consuming 1-2 servings of walnuts per week (1/4 cup per serving) was associated with reduced risk of developing impairments in physical function, which helps enable older women to maintain independence throughout the aging process. (1)
This paper emphasized that overall diet quality, rather than individual foods, may have a greater impact on reducing risk of physical function impairments. Specifically, diet quality traits most associated with reduced rates of incident physical impairment were higher intake of fruits and vegetables; lower intake of sugar-sweetened beverages, trans fat, and sodium; and moderate alcohol intake. Among food components, the strongest relations were found for increased intakes of oranges, orange juice, apples, pears, romaine or leaf lettuce, and walnuts.
"There's a lot of research that looks at specific health conditions in aging, such as diabetes and heart disease, but less attention to research on quality of life and ability to maintain independence with aging," said Dr. Francine Grodstein, ScD, professor of medicine at Brigham and Women's Hospital and Harvard Medical School. "The simple message from this study is that eating an overall healthy diet, including certain foods, such as walnuts and other whole foods, may help women with the ability to do key everyday tasks as they age, like carrying groceries or dressing themselves."
The researchers looked at data from 54,762 women in the Nurses' Health Study, which tracked women for over 30 years. Between 1992 and 2008, the women were asked questions about their physical function, including their ability to perform basic activities of daily living. This new paper prospectively examined the association between the dietary habits of the participants and subsequent impairment in physical function. Diet was assessed using the Alternative Healthy Eating Index (AHEI-2010), a measure of diet quality that incorporates foods and nutrients predictive of chronic disease risk based on scientific evidence.
"These results add to the large body of evidence that outline the many benefits of a healthy diet for women. Additional research is needed to better understand how diet and lifestyle choices can help maintain our health and well-being as we age," said Dr. Grodstein.
There are numerous possible active properties in walnuts that may be contributing factors in providing health benefits. Walnuts are unique among nuts in that they are primarily composed of polyunsaturated fat (13 grams per ounce), which includes alpha-linolenic acid (ALA), the plant-based omega-3 fatty acid. They are the only nut to contain a significant amount of ALA with 2.5 grams per one ounce serving.
Some study limitations should be considered. The sample only included women, so these results may not be generalizable to men. Additionally, participants were not assigned to eat walnuts or other foods, and were just asked about their dietary choices. It is also possible that subjects may have misreported their dietary intake since this information was collected by questionnaires. In addition, because this is an observational study, residual confounding cannot be ruled out (i.e. that other lifestyle habits which are more common in adults who eat walnuts could contribute to the study findings); and, thus, the results should be interpreted with caution.
Study links omega-3s to reduced mortality
A recent meta-analysis in Scientific Reports supports a link between EPA and DHA omega-3 intake and a reduced risk of death by any cause. The meta-analysis included 11 studies involving 371,965 participants and 31,185 death events, with a subset of the studies being used for different analyses.
In the analysis of n-3 LCPUFA intake, there was a 9% reduced risk of all-cause death associated with high versus low omega-3 intake. In the dose-response analysis, an increase in EPA/DHA intake of 300 mg/day was associated with a 6% lower risk of all-cause mortality. These findings suggest that both dietary and circulating n-3 LCPUFA are shown to be significantly associated with reduced risk of all-cause mortality.
According to study author Manfred Eggersdorfer, "The meta-analysis of 11 prospective observational studies demonstrates that each 1% increment of omega-3s in total fatty acids in blood may be associated with a 20% decrease in risk of all-cause mortality. This is an important finding for the potential contribution of adequate omega-3 intake to public health."
Some older adults live well, despite advancing years and the burdens of chronic diseases
You might believe that older adults who deal with extensive chronic illnesses or serious diseases would be more likely to be frail and to have a poorer quality of life than healthier older adults. That may be true for some elders--but not for all. Researchers writing in the Journal of the American Geriatrics Society suggest that an undefined coping mechanism of some sort may play a role in how well older adults are able to live despite having burdensome illnesses.
The researchers examined three groups of participants enrolled in the Cardiovascular Health Study, a large research project that examined adults 65-years-old and older from four cities around the country.
Researchers assigned people to one of three groups, based on the extent of their disease and their level of vigor or frailty:
1. The expected agers (3,528 people) had higher disease but also higher frailty levels. They spent 47 percent of the remainder of their lives able and healthy.
2. The adapters (882 people) had higher disease levels as well as relatively high vigor (being active and mobile) levels. They spent 55 percent of the reminder of their lives able and healthy.
3. The prematurely frail (885 people) had lower disease levels but higher frailty levels. They spent 37 percent of their remaining lives able and healthy.
The researchers said "adapter" older adults who were more vigorous than expected, based on their disease burden, lived longer lives when compared to those who were more frail than expected based on their disease burden. These "adapters" could have unique characteristics, perhaps some undefined coping mechanism, that should be studied further, suggested the researchers.
More reasons to eat your broccoli
Love it or hate it, broccoli is touted as a superfood, offering an array of health benefits. And it's about to get even more super.
University of Illinois researchers have identified candidate genes controlling the accumulation of phenolic compounds in broccoli. Consumption of phenolic compounds, including certain flavonoids, is associated with a lower risk of coronary heart disease, type II diabetes, asthma, and several types of cancer.
"Phenolic compounds have good antioxidant activity, and there is increasing evidence that this antioxidant activity affects biochemical pathways affiliated with inflammation in mammals. We need inflammation because it's a response to disease or damage, but it's also associated with initiation of a number of degenerative diseases. People whose diets consist of a certain level of these compounds will have a lesser risk of contracting these diseases," explains U of I geneticist Jack Juvik.
The researchers crossed two broccoli lines and tested their progeny in terms of total phenolic content and their ability to neutralize oxygen radicals in cellular assays. They then used a genetic technique called quantitative trait locus analysis to search for the genes involved in generating phenolics in the most promising progeny.
By identifying the genes involved in accumulating these compounds, the researchers are one step closer to breeding broccoli and related Brassica vegetables like kale and cabbage with mega-doses of phenolic compounds.
"It's going to take awhile," Juvik notes. "This work is a step in that direction, but is not the final answer. We plan to take the candidate genes we identified here and use them in a breeding program to improve the health benefits of these vegetables. Meanwhile, we'll have to make sure yield, appearance, and taste are maintained as well."
The good news is that phenolic compounds are flavorless and stable, meaning the vegetables can be cooked without losing health-promoting qualities.
Once these vegetables are consumed, the phenolic compounds are absorbed and targeted to certain areas of the body or concentrated in the liver. Flavonoids spread through the bloodstream, reducing inflammation through their antioxidant activity.
"These are things we can't make ourselves, so we have to get them from our diets," Juvik says. "The compounds don't stick around forever, so we need to eat broccoli or some other Brassica vegetable every three or four days to lower the risk of cancers and other degenerative diseases."
Monday, June 20, 2016
Men with prostate cancer: nuts >4 times per week after diagnosis- 34% lower risk of overall mortality
In a large prospective study published online in the British Journal of Cancer*, researchers looked at the association between nut consumption and prostate cancer risk and mortality among 47,299 men in the Health Professionals Follow-up Study. While nut consumption was not associated with a reduced risk of prostate cancer, men who had prostate cancer and consumed tree nuts (almonds, Brazil nuts, cashews, hazelnuts, macadamias, pecans, pine nuts, pistachios and walnuts) five or more times per week after diagnosis, had a significant 34 percent lower risk of overall mortality than those who consumed nuts less than once per month (HR=0.66, 95% CI: 0.52-0.83, P for trend=0.0005).
"This is important," states lead researcher, Ying Bao, MD, ScD, from the Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, "since more men live with prostate cancer than die from it." Prostate cancer is the most commonly diagnosed and second most lethal cancer for men in the U.S.
According to Dr. Bao, of the 4,346 men diagnosed with non-metastatic (cancer that has not spread from the place where it started to other places in the body) prostate cancer during the 26 years of follow-up, only about 10 percent died from prostate cancer. Roughly one third of the cancer patients died from cardiovascular disease and the rest from other causes.
Increasing evidence suggests that insulin resistance, a condition in which the cells of the body become resistant to the hormone insulin, is involved in prostate cancer risk and progression. Tree nuts have been associated with improved insulin sensitivity and reduced risk of diabetes, cardiovascular disease and total mortality**. Nuts contain important nutrients such as unsaturated fats, high quality protein, vitamins (i.e., vitamin E, folate and niacin) minerals (i.e., magnesium, calcium and potassium) and phytochemicals--all of which may offer cardioprotective, anticarcinogenic, anti-inflammatory and antioxidant properties.
"These findings add to the growing body of evidence showing that nuts can and should be part of a healthy diet," states Maureen Ternus, M.S., R.D., Executive Director of the International Tree Nut Council Nutrition Research & Education Foundation (INC NREF). "During the summer months especially, tree nuts are a great, portable snack to take to the beach, on a hike, or camping," adds Ternus. "Just 1.5 ounces of nuts per day (about 1/3 cup) can have a positive impact on health."
Seven servings of whole grains a day keep the doctor away
Eating three more portions of dietary fiber a day--say, two pieces of whole grain bread and a bowl of whole grain breakfast cereal--is associated with a lower risk for all cardiovascular diseases and for dying of cancer, diabetes, and respiratory and infectious diseases, a study just published in the BMJ has shown. The study is strong proof that consuming lots of whole grains is good for our health, says first author Dagfinn Aune, a PhD candidate at the Norwegian University of Science and Technology who is currently working at Imperial College, London.
The meta-analysis isn't the first study that links whole grains to positive health effects, but it is the first one to look at how much whole grain one should eat to minimize health risks and that has examined the connection with various causes of death. In general, the study showed that the higher the consumption, the better protected you are.
"We saw the lowest risk among people who ate between seven and seven and a half servings of whole grain products a day, which was the highest intake across all the studies. This corresponds to 210-225 grams of whole grain products in fresh weight and about 70-75 grams of whole grains in dry weight, and is about the same as the health authorities in Norway and other Nordic countries recommend as the minimum daily allowance," says Aune.
Applies only to whole grain products
The researchers' analyses showed fewer risk factors for people who consumed more bread and cereal with whole grains, as well as foods with added bran. On the other hand, people who ate a lot of white bread, rice or cereals with refined grains did not show reduced risk.
"A lot of folks eat plenty of grains, but they choose refined breads instead of varieties with more dietary fiber. Our study suggests that you can reduce the risk of premature death by replacing a big part of the white flour in your diet with whole grain products," said Aune.
Some of the beneficial health effects of eating whole grains may lie in their high fiber content. A high intake of dietary fiber can stabilize blood sugar levels, lower blood pressure, cholesterol, and levels of inflammatory markers in the blood, and can positively affect the gut environment. All of this can contribute to a reduced risk of diabetes, cardiovascular disease and cancer.
Whole grain products also contain several other biologically active substances, such as antioxidants, B vitamins, iron, magnesium, and zinc. It is probably the whole package of favorable components that contribute to the positive effect on the risk of chronic disease and mortality.
Something is much better than nothing
Aune and an international group of researchers collected data from 45 different population studies that investigated whole grain intake in relation to risk of future illness or death due to specific causes.
To be included, the scientists required risk estimates in the studies to be adjusted for other factors that could affect the relationship between dietary fiber intake and health. The findings are now being published in The BMJ, one of the highest ranked medical journals, and reviewed in an editorial in the same issue.
In the editorial, Cecilie Kyrø and Anne Tjønneland from the research centre of the Danish Cancer Society, wrote, "Today, the Nordic countries have the most specific recommendations in the world for how much dietary fiber you should eat: 70-90 grams a day in dry weight, which corresponds to about 210-270 grams of product.
In Denmark, the intake of whole grains has doubled over the last ten years, thanks to the food and health authorities ensuring that food may not be labeled as whole grain if it does not meet strict content requirements. But even in Denmark, no more than 6% of the population follow the recommendations to eat seven or more servings of whole grains a day.
Nevertheless, the researchers believe it is possible to get more people to eat that much whole grain, both in Scandinavia and other countries.
"It may seem ambitious, but effective campaigns and product development can lead to much greater consumption of whole grains. When the health authorities implement measures to increase the population's dietary fibre intake, it is important not to promote whole grain products with a high sugar and salt content," write the Danish researchers, and they point out that greatest health impact at the population level can be achieved by getting more people to eat some whole grains instead of none.
This idea is also supported by the meta-analysis findings.
"We found the greatest risk reduction in people who consumed 0 grams up to those who ate 50 grams of whole grain products a day. The risk continued to decrease - but to a lesser extent - up to an intake of 225 grams a day," said Aune.
Reduced mortality risk for many diseases
Nine studies with a total of more than 700,000 participants examined the risk for all types of cardiovascular disease and correlated cardiovascular deaths. The half of the study subjects who ate the most whole grains had a 16% lower risk than those who consumed less, and every third portion more of whole grain a day reduced the risk by 22%.
The seven studies that looked at coronary heart disease (heart attack and angina) showed similar risk estimates, whereas the reduced risk of stroke was slightly lower in the combined analyses of the six studies that examined this. Analyses of whole grains and mortality from stroke showed a statistically significant 14% reduction in risk.
The risk of dying prematurely from all causes was 18% lower for individuals who consumed a lot of whole grains compared to those who consumed lesser amounts, while three additional servings each day were associated with a 17% reduction in mortality. The risk for deaths associated with cancer (15%), respiratory diseases (22%), diabetes (51%) and infectious diseases (26%) was also lower the more whole grains individuals consumed.
Still need more research
The researchers acknowledge the limitations in measuring how much grain was eaten via self-reported data and that the various studies may have had different definitions for what was regarded as whole grain products. The researchers also cannot rule out that the results may be influenced by people who eat lots of whole grains also living healthier in other ways, but point out that they got the same results when they only analysed studies that adjusted for smoking, alcohol consumption, BMI, physical activity and consumption of other foods such as red meat, sugary drinks and fruits and vegetables.
"Future studies need to improve the way grain intake is measured, and more research that looks at whether the different types of whole grains can have different effects on health is also needed. For example, some studies indicate that oats and rye are better whole grain sources than wheat in terms of reducing the risk of cardiovascular disease," the Danish researchers Kyrø and Tjønneland write.
And a lot of research is still missing on the relationship between dietary fibre intake and relatively rare causes of death.
Aune says that much of the research on whole grains so far has been focused on the most widespread illnesses such as cardiovascular diseases, cancers (mainly colorectal cancer) and type 2 diabetes. "However, our results suggest that consuming whole grain products may have beneficial effects on several other diseases, like mortality from respiratory diseases and infections, and the literature suggests that whole grains may even protect against rare cancers.
Now several very large population-based studies have been established, allowing us to examine less common diseases in more detail than previously. So we'll continue to examine the relationship between whole grains and diseases that have only been studied minimally or not at all," he says.
Piping hot drinks may lead to cancer of the esophagus
Drinking piping hot coffee, tea and the caffeine-infused beverage yerba mate probably causes cancer, the World Health Organization announced Wednesday.
Beverages surpassing 149 degrees Fahrenheit (65 degrees Celsius) may increase the risk of tumors in the esophagus, which resides in the chest area below the throat, according to USC's Mariana Stern and 22 other scientists from 10 countries. They met at the WHO's International Agency for Research on Cancer in Lyon, France, in May to determine if drinking coffee, mate or other very hot beverages causes cancer. Their results were published in the journal Lancet on June 15.
"Enjoy your coffee or mate, but make sure it's not very hot," said Stern, an associate professor of preventive medicine and urology at the Keck School of Medicine of USC. "There is physical evidence that very hot beverages can contribute to cell injury in the esophagus and thus contribute to cancer formation."
The group scoured more than 1,000 studies on over 20 different types of cancer. The scientists concluded drinking any beverage hotter than 149 degrees Fahrenheit is "probably carcinogenetic to humans," placing scalding hot drinks in the same category as DDT, frying food at high temperatures, consumption of red meat and the human papillomavirus.
According to the National Coffee Association, coffee waiting to be served should sit at 180-185 degrees Fahrenheit (82-85 degrees Celsius). That's around the temperature McDonald's restaurants served coffee before a well-known lawsuit prompted the fast food chain to sell coffee at a temperature of 10 degrees lower - still far above what the researchers consider safe.
In the United States, the average coffee drinking temperature is around 140 degrees Fahrenheit (60 degrees Celsius). The temperature varies between 99-190 degrees Fahrenheit (37-88 degrees Celsius), Stern said.
"We were now able to evaluate more carefully the effect of mate itself from the effect of temperature, and we concluded that the observed links between mate drinking and cancer of the esophagus seem to be largely driven by drinking mate very hot," Stern said. "Similar associations are seen for other very hot beverages, like tea or coffee."
Stern and her colleagues noted that drinking yerba mate at very high temperatures - between 150 and right below the boiling point of 212 degrees Fahrenheit (66-100 degrees Celsius) - is common practice in certain countries in South America, including Argentina, Uruguay and Paraguay.
A cup of coffee a day may keep liver cancer away
The scientists downgraded a cup of joe from "possibly carcinogenic" and hot mate from "probably carcinogenic" to safe for consumption as long as neither are scalding hot.
In 1991, the WHO gave coffee that classification based on a much smaller database of studies. Now, the scientists highlighted some studies that associated coffee with cancer when the real culprit was probably tobacco smoking, which is highly correlated with heavy coffee drinking, according to the report.
Late last year, Stern participated in a WHO group that concluded consuming processed meat - bacon, salami, sausages, hot dogs and deli meats - causes cancer.
However, the news about coffee was not grim. The researchers estimate that a cup of coffee a day decreases the risk of liver cancer by 15 percent. In other words, the scientists are giving coffee lovers a free pass to drink as much coffee as their bladders can handle.
"For many cancer types, we found clear evidence that coffee is not carcinogenic," Stern said. "In fact, we found that coffee protects against some cancers such as liver and uterine endometrium cancer."
Exercise can help adults better cope with ADHD symptoms
Exercise, even a small amount, can help alleviate symptoms of ADHD in adults, according to a new study by University of Georgia researchers.
The study, released this month in the journal Medicine and Science in Sports and Exercise, found a single bout of exercise has psychological benefits for adults with these elevated ADHD symptoms. About 6 percent of American adults report symptoms consistent with attention deficit hyperactivity disorder, or ADHD, which lead to anxiety, depression, low energy and motivation, poor performance at work or school and also increased traffic accidents.
"Exercise is already known as a stress reducer and mood booster, so it really has the potential to help those suffering with ADHD symptoms," said the study's senior author Patrick O'Connor, professor in the UGA College of Education's kinesiology department. "And while prescription drugs can be used to treat these symptoms, there's an increased risk of abuse or dependence and negative side effects. Those risks don't exist with exercise."
The study tested 32 young men with elevated ADHD symptoms who cycled at a moderate intensity for 20 minutes on one day, and on another day sat and rested for 20 minutes as a control condition. The participants were asked to perform a task requiring focus both before and after the different conditions, and researchers noted leg movement, mood, attention and self-reported motivation to perform the task.
As a result, researchers found that it was only after the exercise when the participants felt motivated to do the task; they also felt less confused and fatigued and instead felt more energetic. Interestingly, leg movements and performance on the task did not change after the exercise--rather, the exercise helped the young men feel better about doing the task.
These findings are consistent with prior research that shows a single bout of exercise helps people feel more energetic, said O'Connor, who is also co-director of the UGA Exercise Psychology Laboratory. The results suggest that young men who have symptoms of ADHD can benefit psychologically from the short workouts, similar to the benefits enjoyed by typical adults who work out.
"The reduced feelings of confusion and increased motivation to perform a cognitive task suggest that other types of acute exercise also may benefit cognitive performance," added study co-author Kathryn Fritz, a UGA doctoral student who completed the study as part of her master's thesis. "We speculate that a different mode or duration or intensity of exercise, other than a boring cycle ride in a sterile lab, may show larger cognitive effects for those suffering from ADHD symptoms."
Effect may stem from anti-inflammatory properties
A Washington State University researcher has found that statin drugs can dramatically lower the risk of infections in stroke patients.
Doug Weeks, an adjunct professor in the Elson S. Floyd College of Medicine and director of research at St. Luke's Rehabilitation Institute, analyzed the records of more than 1,600 hospitalized patients who suffered an ischemic stroke and found statins reduced the risk of infection by 58 percent. Ischemic strokes are due to blockage of a vessel that supplies blood to the brain. His findings appear online this month in the Journal of Stroke and Cerebrovascular Diseases.
"If patients had statins before there was evidence of an infection, there was a reduced risk that they would actually develop an infection," said Weeks.
Statins are typically used to lower cholesterol levels to reduce the risk of cardiovascular disease. But in the past decade, said Weeks, researchers have noticed that they also have anti-inflammatory properties in humans that can benefit the body's response to infection.
Weeks analyzed data of hospitalized stroke patients and saw that those on statins upon admission or early in their stay had significantly lower risk for developing infections than those put on statins later in their hospitalization or not at all. Weeks controlled for other possible influences like the severity of strokes, age and the presence of other conditions like diabetes.
He and his colleagues also noticed that the timing of the drug was a major factor.
"The administration of statins relative to infection is critically important," he said. "We've been able to establish that if statins are given early, before infection can occur, the risk of infection is substantially reduced. However, this relationship needs to be tested in more rigorous placebo-controlled studies to see if this benefit with statins is maintained."
Estimates vary, but one-third to almost one-half of stroke patients develop infections, he said. The infections could be introduced through tubes or catheters. There are also indications that stroke subdues the body's immune system, making a patient more prone to infection.
Tuesday, June 14, 2016
15 minutes of physical activity a day was associated with a 22 percent lower risk of death
Fifteen minutes of daily exercise is associated with a 22% lower risk of death and may be a reasonable target for older adults, reveals research presented today at the EuroPRevent 2016 meeting by Dr David Hupin, a physician in the Department of Clinical and Exercise Physiology, University Hospital of Saint-Etienne in Saint-Etienne, France.1
"Age is not an excuse to do no exercise," said Dr Hupin. "It is well established that regular physical activity has a better overall effect on health than any medical treatment. But less than half of older adults achieve the recommended minimum of 150 minutes moderate intensity or 75 minutes vigorous intensity exercise each week."
He continued: "We wanted to find out whether lower levels of exercise could be beneficial and even reduce mortality in older adults."
The authors studied two cohorts. A French cohort of 1011 subjects aged 65 in 2001 was followed over a period of 12 years. An international cohort of 122 417 subjects aged 60 was included from a systematic review and meta-analysis using PubMed and Embase databases, with a mean follow up of 10 years.2
Physical activity was measured in Metabolic Equivalent of Task (MET) minutes per week, which refers to the amount of energy (calories) expended per minute of physical activity. One MET minute per week is equal to the amount of energy expended just sitting. The number of MET minutes an individual clocks up every week depends on the intensity of physical activity. For example, moderate intensity activity ranges between 3 and 5.9 MET minutes while vigorous intensity activity is classified as 6 or more.
The recommended levels of exercise equate to between 500 and 1000 MET minutes every week. The authors looked at the associated risk of death for four categories of weekly physical activity in MET minutes, defined as inactive (reference for comparison), low (1-499), medium (500-999) or high (?1000).
During the follow up there were 88 (9%) and 18 122 (15%) deaths in the French and international cohorts, respectively. The risk of death reduced in a dose response relationship as the level of exercise increased. Compared to those who were inactive, older adults with low, medium and high activity levels had a 22%, 28% and 35% lower risk of death, respectively.
Dr Hupin said: "These two studies show that the more physical activity older adults do, the greater the health benefit. The biggest jump in benefit was achieved at the low level of exercise, with the medium and high levels bringing smaller increments of benefit."
"We found that the low level of activity, which is half the recommended amount, was associated with a 22% reduced risk of death in older adults compared with those who were inactive," said Dr Hupin. "This level of activity equates to a 15 minute brisk walk each day."
He concluded: "We think that older adults should progressively increase physical activity in their daily lives rather than dramatically changing their habits to meet recommendations. Fifteen minutes a day could be a reasonable target for older adults. Small increases in physical activity may enable some older adults to incorporate more moderate activity and get closer to the recommended 150 minutes per week."
Healthy plant-based diet linked with substantially lower type 2 diabetes risk
Consuming a plant-based diet--especially one rich in high-quality plant foods such as whole grains, fruits, vegetables, nuts, and legumes--is linked with substantially lower risk of developing type 2 diabetes, according to a new study from Harvard T.H. Chan School of Public Health.
"This study highlights that even moderate dietary changes in the direction of a healthful plant-based diet can play a significant role in the prevention of type 2 diabetes," said Ambika Satija, postdoctoral fellow in the Department of Nutrition, lead author of the study. "These findings provide further evidence to support current dietary recommendations for chronic disease prevention."
The study will be published online June 14, 2016 in PLOS Medicine.
While previous studies have found links between vegetarian diets and improved health outcomes, including reduced risk of type 2 diabetes, this new study is the first to make distinctions between healthy plant-based diets and less healthy ones that include things like sweetened foods and beverages, which may be detrimental for health. The study also considered the effect of including some animal foods in the diet.
The researchers followed more than 200,000 male and female health professionals across the U.S. for more than 20 years who had regularly filled out questionnaires on their diet, lifestyle, medical history, and new disease diagnoses as part of three large long-term studies. The researchers evaluated participants' diets using a plant-based diet index in which they assigned plant-derived foods higher scores and animal-derived foods lower scores.
The study found that high adherence to a plant-based diet that was low in animal foods was associated with a 20% reduced risk of type 2 diabetes compared with low adherence to such a diet. Eating a healthy version of a plant-based diet was linked with a 34% lower diabetes risk, while a less healthy version--including foods such as refined grains, potatoes, and sugar-sweetened beverages--was linked with a 16% increased risk.
Even modestly lowering animal food consumption--for example, from 5-6 servings per day to about 4 servings per day--was linked with lower diabetes incidence, the study found.
"A shift to a dietary pattern higher in healthful plant-based foods, such as vegetables, fruits, whole grains, legumes, nuts, and seeds, and lower in animal-based foods, especially red and processed meats, can confer substantial health benefits in reducing risk of type 2 diabetes," said Frank Hu, professor of nutrition and epidemiology at Harvard Chan School and senior author of the study.
The researchers suggested that healthful plant-based diets could be lowering type 2 diabetes risk because such diets are high in fiber, antioxidants, unsaturated fatty acids, and micronutrients such as magnesium, and are low in saturated fat. Healthy plant foods may also be contributing to a healthy gut microbiome, the authors said.
Limitations of the study include possible measurement errors because the data was self-reported, although the authors noted that because the study cumulatively measured diet over time, it reduced such errors. The authors also said that their findings need to be replicated in other populations.
Glass of cranberry juice a day reduces symptomatic urinary tract infections
According to a new study, recently published by the American Journal of Clinical Nutrition, drinking an 8-ounce (240 ml) glass of cranberry juice a day reduces symptomatic urinary tract infections (UTIs) by nearly 40 percent in women with recurrent UTIs - reducing the burden of UTIs and reducing the antibiotic use associated with treating recurrent UTIs.
"Currently the primary approach to reducing symptomatic events of UTI is the use of chronic antibiotics for suppression, an approach associated with side effects and development of antibiotic resistance. This study shows that consuming one 8-ounce (240 ml) glass of cranberry juice a day reduces the number of times women suffer from repeat episodes of symptomatic UTI and avoids chronic suppressive antibiotics," said Dr. Kalpana Gupta, infectious disease specialist and Professor of Medicine at Boston University's School of Medicine.
An author on the study and panelist at today's session, Dr. Gupta believes that cranberries can help to reduce the worldwide use of antibiotics and significantly improve the quality of life for women who suffer from recurrent UTI symptoms.
Single Largest Clinical Trial on Cranberries of its Kind
The 24-week study of 373 women, conducted by researchers at Boston University, Biofortis Innovation Services (a division of Merieux Nutrisciences) and 18 clinical sites throughout the US and France, is the largest clinical trial of its kind examining the effects of cranberry juice consumption on UTIs. This trial adds to more than 50 years of cranberry research and supports the cranberry's ability to support urinary tract health and reduce symptomatic UTIs among chronic UTI sufferers.
Researchers set out to find whether recurrent (or repeat) UTI sufferers could be protected from repeat infections by drinking cranberry juice. Participants were all healthy women, with an average age of 40, who had experienced at least two UTIs within the past year. During the study, participants were randomly chosen to drink a daily dose of eight ounces (240 ml) of either cranberry juice or a "placebo" beverage without cranberries.
The rate of UTIs decreased significantly among the cranberry drinkers, with just 39 diagnoses during the six-month study compared with 67 in the placebo group.
Compared to some other studies, this trial had greater statistical power to detect differences than others due to its larger sample, use of incidence density to account for the tendency of clinical UTIs to cluster in time within an individual, a high average level of compliance (98%), and a comparatively large percentage of subjects in each group completing the treatment period (86%).
What's in a Symptom?
Women with symptomatic UTIs experience all the discomforts of a UTI, such as a strong, persistent urge to urinate or a burning sensation when urinating, but may or may not test positive for a bacterial infection upon a consult with a physician. In many instances, women are treated with antibiotics for symptom relief whether bacteria is found or not. According to Gupta, the key to avoiding the situation altogether may very well lay with the cranberry.
"The key to cranberry's benefit is consuming a glass daily to help avoid the infection altogether," said Gupta. "Most people wait to drink cranberry juice until they have a UTI, but once the symptoms start they'll likely need a course of antibiotics."
The Correlation between UTIs and Antibiotic Resistance
UTIs are among the most common bacterial infections in women worldwide. Up to 60 percent of all women suffer a UTI in their lifetime,(1) and up to 25 percent experience a recurrence within six months.(2) Some 150 million UTIs occur annually worldwide, according to the American Urological Association, resulting in $6 billion in annual health care costs.(3)
Antibiotics are usually the first line of treatment for urinary tract infections, and women who have frequent UTIs may be prescribed low-dose antibiotics. Unfortunately, chronic overuse of these drugs has increased antibiotic resistance at an alarming rate globally. So much in fact, that the World Health Organization (WHO) cites a 50 percent resistance rate to one of the most widely used antibiotics to treat UTIs.(4)
How Cranberries Work
Luckily, cranberries contain a unique combination of compounds including Type-A PACs (or proanthocyanidins) that prevent bacteria from sticking and causing infection. In addition to PACs, new studies have revealed a new class of compounds, xyloglucan oligosaccharides, which have similar anti-bacterial properties against E. coli as PACs.(5) This means there are multiple, unique elements within cranberries working hard for your health.
These unique compounds can be found in a variety of products, including cranberry juice cocktail, 100% cranberry juice, light cranberry juice, dried cranberries and cranberry extract; however most of the research surrounding cranberries and UTIs has been conducted using juice.
Monday, June 13, 2016
Eating more whole grains linked with lower mortality rates
Eating more whole grains may reduce the risk of premature death, according to a new meta-analysis by researchers from Harvard T.H. Chan School of Public Health. The study found that people who ate the most whole grains (70 grams/day, about 4 servings), compared with those who ate little or no whole grains, had a lower risk of dying during the study period.
"These findings further support current dietary guidelines that recommend at least 3 daily servings (or 48 grams) of whole grains to improve long-term health and prevent premature death," said Qi Sun, assistant professor in the Department of Nutrition and senior author of the study.
The study will appear online June 13, 2016 in Circulation.
Previous studies have found that whole grains may reduce risk of cardiovascular disease (CVD), diabetes, and poor gut health, among other conditions.
The meta-analysis combined results from 12 published studies, in addition to unpublished results from the National Health and Nutrition Examination Survey (NHANES) III and NHANES 1999-2004. The studies were conducted in the United States, the United Kingdom, or in Scandinavian countries between 1970 and 2010. Health information from 786,076 participants was included in the analysis.
The results showed that people who ate 70 grams/day of whole grains, compared with those who ate little or no whole grains, had a 22% lower risk of total mortality, a 23% lower risk of CVD mortality, and a 20% lower risk of cancer mortality.
Mortality rate is a measure of the number of deaths in a particular population for a specific period of time.
The researchers note that multiple bioactive compounds in whole grains could contribute to their health benefits, and that high fiber content may lower cholesterol production and glucose response and increase satiety.
The researchers recommend that people choose foods that are high in whole grain ingredients--such as bran, oatmeal, and quinoa--that have at least 16 grams per serving, while reducing consumption of unhealthy refined carbohydrates.
One limitation of the meta-analysis was that some of the studies used were carried out before a more consistent definition of whole grains became available; therefore, lists of whole grain foods varied substantially among individual studies. In addition, as most of the studies were from the U.S. and Scandinavian countries, it is not known whether these findings can be generalized to other populations.
Friday, June 10, 2016
Midlife fitness is linked to lower stroke risks later in life
The more fit you are in your midlife, the less likely you are to have a stroke after age 65, according to new research in the American Heart Association's journal Stroke.
"We all hear that exercise is good for you, but many people still don't do it. Our hope is that this objective data on preventing a fatal disease such as stroke, will help motivate people to get moving and get fit," said Ambarish Pandey, M.D., the first author of the study and a cardiology fellow at the University of Texas Southwestern Medical Center in Dallas, Texas.
In a prospective observational study consisting of 19,815 adults ages 45 to 50, (79 percent men, 90 percent Caucasian) researchers measured participants' heart and lung exercise capacity-cardiorespiratory fitness-and categorized them as having either a high, middle or low level of fitness.
The study found that those with the highest level of fitness had a 37 percent lower risk of stroke after age 65, compared to their counterparts with the lowest level of fitness. This inverse relationship between fitness and stroke risks existed even after researchers considered stroke risk factors: high blood pressure, Type 2 diabetes and atrial fibrillation.
"These findings support the unique and independent role of exercise in the prevention of stroke," said senior study author Jarett Berry, M.D., an associate professor of Internal Medicine at UT Southwestern.
Stroke is the No. 5 cause of death in the United States and a leading cause of serious long-term disability. The information on the effects of fitness on stroke risk, independent of other factors, is limited, researchers noted.
The study reinforces the benefits of being physically fit throughout life.
"Low fitness is generally ignored as an actual risk factor in clinical practice," Pandey said. "Our research suggests that low fitness in midlife is an additional risk to target and help prevent stroke later in life."
The study was performed in collaboration with the Cooper Institute in Dallas, Texas. The investigators used data from the Cooper Center Longitudinal Study, collected between 1999 and 2009, that measured exercise tolerance with a standardized treadmill test when participants were age 45 to 50.
"In this study we see an association between fitness and reduced risk of the serious health event of stroke even in the presence of other chronic conditions," said Benjamin Willis, M.D., coauthor of the study and epidemiologist at The Cooper Institute.
The American Heart Association recommends 150 minutes of moderate exercise or 75 minutes of vigorous exercise weekly. As a rule of thumb, exercise thirty minutes a day, five times a week, for better overall cardiovascular health.
Wednesday, June 8, 2016
Mediterranean diet high in healthy fat does not lead to weight gain,
Focus on low-fat diets and lack of differentiation between healthy and unhealthy fat has led to 'paradoxical policies' about healthy eating
Eating a non-calorie restricted Mediterranean diet high in vegetable fats such as olive oil or nuts does not lead to significant weight gain compared to a low-fat diet, according to a large randomised trial published today in The Lancet Diabetes & Endocrinology journal. The study suggests that current health guidelines that recommend a low-fat, low-calorie diet create unnecessary fear of healthy fats present in a Mediterranean diet, which have known health benefits.
Accumulating scientific evidence suggests that total fat content is not a useful measure of harms or benefits of food, and that fats from nuts, fish and phenolic-rich vegetable oils are healthier than fats from meat and processed foods.
"More than 40 years of nutritional policy has advocated for a low-fat diet but we're seeing little impact on rising levels of obesity," says lead author Dr Ramon Estruch, CIBER OBN-University of Barcelona, Spain. "Our study shows that a Mediterranean diet rich in vegetable fats such as olive oil and nuts had little effect on bodyweight or waist circumference compared to people on a low-fat diet. The Mediterranean diet has well-known health benefits and includes healthy fats such as vegetable oils, fish and nuts. Our findings certainly do not imply that unrestricted diets with high levels of unhealthy fats such as butter, processed meat, sweetened beverages, deserts or fast-foods are beneficial." [1]
Obesity is a key risk factor for cardiovascular disease, type 2 diabetes, some cancers and musculoskeletal disorders. The standard recommendation for the prevention and treatment of obesity is a reduced-fat diet and increased physical activity, and many health organisations including WHO recommend a limit of 30% fat for total energy intake [2].
Perceptions of all fat as unhealthy have resulted in decreased fat consumption in the US population, but the epidemics of obesity and diabetes have continued to grow. Numerous studies have shown that the Mediterranean diet, which includes high levels of vegetable fats (e.g. olive oil, nuts), is linked to reduced mortality, cardiovascular disease and cancer, but fears of eating all fat mean that a low-fat diet continues to be recommended as a means of weight loss.
The study took place in 11 hospitals in Spain during 2003-2010 and included 7447 participants (men and women) aged 55-80 who were randomly assigned to one of three groups - an unrestricted-calorie Mediterranean diet rich in olive oil (2543), an unrestricted-calorie Mediterranean diet rich in nuts (2454), or a low-fat diet where the advice was to avoid all dietary fat (2450) [3]. Trained dieticians gave personalised dietary advice to all participants.
Adherence to the diets was good and monitored by questionnaires for all participants and by taking blood and urine samples in a random subgroup. All participants were at high cardiovascular risk [4] or had type 2 diabetes, and more than 90% were overweight or obese.
After 5 years, total fat intake had decreased in the low-fat diet group (from 40% to 37.4%) and had slightly increased in both Mediterranean diet groups (40% to 41.8% in olive oil; 40.4% to 42.2% in nuts). The percentage of energy intake from protein and carbohydrate decreased in both Mediterranean diet groups.
On average, participants in all three groups lost some weight with the greatest weight loss seen in the Mediterranean diet with olive oil group (0.88 kg weight reduction in the olive oil group, compared to 0.60 kg for the low-fat diet group and 0.40 kg for the nuts group - figure 2). There was an increase in waist circumference in all three groups with the greatest increase seen in the low-fat diet group (1.2 cm increase for the low-fat diet group, compared to 0.85 cm for the olive oil group and 0.37 cm for the nuts group - figure 3).
Writing in a linked Comment, Professor Dariush Mozaffarian, Friedman School of Nutrition Science & Policy at Tufts University, Boston, MA, USA says: "Ironically, just as focusing on total fat to prevent heart disease was misguided because it overlooked the different effects of specific fatty acids, the prioritisation of total calories (and by extension, total fat) to prevent weight gain ignores the diverse physiological effects of different foods. Although the rationale has morphed over time, the end result is similar: a proliferation of fat-reduced--and often correspondingly starch-rich and sugar-rich--foods and diets, with paradoxical warnings and caveats about eating healthy, high-fat foods, such as those rich in nuts and vegetable oils."
"Dietary guidelines should be revised to lay to rest the outdated, arbitrary limits on total fat consumption. Calorie-obsessed caveats and warnings about healthier, higher-fat choices such as nuts, phenolic-rich vegetable oils, yoghurt, and even perhaps cheese, should also be dropped. We must abandon the myth that lower-fat, lower-calorie products lead to less weight gain. This illusion leads to paradoxical policies that focus on total calories, rather than food quality, on restaurant menus; ban whole milk but allow sugar-sweetened fat-free milk; compel food manufacturers, retailers, and restaurants to remove healthy vegetable-derived fats from meals and products while heavily marketing fat-reduced products of dubious health value; and mislead consumers to select foods based on total fat and calorie contents rather than actual health effects."
"The fat content of foods and diets is simply not a useful metric to judge long-term harms or benefits. Energy density and total caloric contents can be similarly misleading. Rather, modern scientific evidence supports an emphasis on eating more calories from fruits, nuts, vegetables, beans, fish, yoghurt, phenolic-rich vegetable oils, and minimally processed whole grains; and fewer calories from highly processed foods rich in starch, sugar, salt, or trans-fat. We ignore this evidence-- including these results from the PREDIMED trial--at our own peril."
Friday, June 3, 2016
Beer Drinking May Be Protective against Alzheimer's
While most people will agree that excessive
consumption of alcohol can have a detrimental effect on the brain, there
is less agreement regarding the effects of light or moderate drinking.
This includes concern and controversy surrounding the effects of
drinking on the development of neurodegenerative diseases such as
Alzheimer's (AD). This study investigated the association between
consumption of different alcoholic beverages -- beer, wine, and spirits
-- and one of the neuropathological signs of Alzheimer's disease,
β-amyloid (Aβ) aggregation in the brain.
Researchers examined data from 125 males participating in the
Helsinki sudden death autopsy series, who at the time of death were 35
to 70 years old. Consumption of alcohol, Aβ aggregation in the brain,
and apolipoprotein E (APOE) genotype were assessed. Surviving relatives
answered a questionnaire used to gather the drinking history of the
deceased, and Aβ was observed by immunohistochemical staining of brain
sections.
Findings suggest that beer consumption may protect against Aβ aggregation in the brain. The amount of alcohol consumed was not linked with Aβ aggregation, and neither was spirit or wine consumption. Given that the development of dementia occurs over several years and even decades, the authors call for additional studies to identify early and mid-life factors that may stimulate or protect against Aβ aggregation.
Findings suggest that beer consumption may protect against Aβ aggregation in the brain. The amount of alcohol consumed was not linked with Aβ aggregation, and neither was spirit or wine consumption. Given that the development of dementia occurs over several years and even decades, the authors call for additional studies to identify early and mid-life factors that may stimulate or protect against Aβ aggregation.
Journal Reference: Eloise H. Kok, Toni T. Karppinen, Teemu Luoto, Irina Alafuzoff, Pekka J. Karhunen. Beer Drinking Associates with Lower Burden of Amyloid Beta Aggregation in the Brain: Helsinki Sudden Death Series. Alcoholism: Clinical and Experimental Research,
Dietary fiber intake tied to successful aging
Most people know that a diet high in fiber helps to keep us "regular." Now Australian researchers have uncovered a surprising benefit of this often-undervalued dietary component.
A new paper -- published in The Journals of Gerontology, Series A: Biological Sciences and Medical Sciences by scientists from The Westmead Institute for Medical Research -- reports that eating the right amount of fiber from breads, cereals, and fruits can help us avoid disease and disability into old age.
Using data compiled from the Blue Mountains Eye Study, a benchmark population-based study that examined a cohort of more than 1,600 adults aged 50 years and older for long-term sensory loss risk factors and systemic diseases, the researchers explored the relationship between carbohydrate nutrition and healthy aging.
They found that out of all the factors they examined -- which included a person's total carbohydrate intake, total fiber intake, glycemic index, glycemic load, and sugar intake -- it was the fiber that made the biggest difference to what the researchers termed "successful aging."
Successful aging was defined as including an absence of disability, depressive symptoms, cognitive impairment, respiratory symptoms, and chronic diseases including cancer, coronary artery disease, and stroke.
According to lead author of the paper, Associate Professor Bamini Gopinath, PhD, from the Institute's Centre for Vision Research, the study is the first to look at the relationship between carbohydrate intake and healthy aging, and the results were significant enough to warrant further investigation.
"Out of all the variables that we looked at, fiber intake -- which is a type of carbohydrate that the body can't digest -- had the strongest influence," she said. "Essentially, we found that those who had the highest intake of fiber or total fiber actually had an almost 80 percent greater likelihood of living a long and healthy life over a 10-year follow-up. That is, they were less likely to suffer from hypertension, diabetes, dementia, depression, and functional disability."
While it might have been expected that the level of sugar intake would make the biggest impact on successful aging, Gopinath pointed out that the particular group they examined were older adults whose intake of carbonated and sugary drinks was quite low.
Although it is too early to use the study results as a basis for dietary advice, Gopinath said the research has opened up a new avenue for exploration.
"There are a lot of other large cohort studies that could pursue this further and see if they can find similar associations. And it would also be interesting to tease out the mechanisms that are actually linking these variables," she said.
This study backs up similar recent findings by the researchers, which highlight the importance of the overall diet and healthy aging.
In another study published last year in The Journals of Gerontology, Westmead Institute researchers found that, in general, adults who closely adhered to recommended national dietary guidelines reached old age with an absence of chronic diseases and disability, and had good functional and mental health status.
Long-term of marijuana: no differences in metabolism, lung function, inflammation
A long-term study of nearly 1,000 New Zealanders from birth to age 38 has found that people who smoked marijuana for up to 20 years have more gum disease, but otherwise do not show worse physical health than non-smokers.
The international research team assessed a dozen measures of physical health, including lung function, systemic inflammation and several measures of metabolic syndrome, including waist circumference, HDL cholesterol, triglycerides, blood pressure, glucose control and body mass index.
Tobacco users in the study, which appears online the week of June 1 in JAMA Psychiatry, were found to have gum disease as well as reduced lung function, systemic inflammation and indicators of poorer metabolic health.
“We can see the physical health effects of tobacco smoking in this study, but we don’t see similar effects for cannabis smoking,” said Madeline Meier, an assistant professor of psychology at Arizona State University who conducted the study with colleagues at Duke University, King’s College in the UK and the University of Otago in New Zealand.
While study participants who had used marijuana to some degree over the last 20 years showed an increase in periodontal disease from age 26 to 38, they did not differ from non-users on any of the other physical health measures. To measure cannabis use, they asked study subjects to self-report their use at ages 18, 21, 26, 32 and 38.
The study’s statistical analysis found that the decline in periodontal health in pot smokers was not explained by tobacco smoking, alcohol abuse or less tooth brushing and flossing. The lack of physical health problems among cannabis users also was not attributable to their having had better health to begin with or to living healthier lifestyles.
“We don’t want people to think, ‘Hey, marijuana can’t hurt me,’ because other studies on this same sample of New Zealanders have shown that marijuana use is associated with increased risk of psychotic illness, IQ decline and downward socioeconomic mobility,” Meier said.
“What we’re seeing is that cannabis may be harmful in some respects, but possibly not in every way,” said study co-author Avshalom Caspi, the Edward M. Arnett Professor of psychology and neuroscience at Duke. “We need to recognize that heavy recreational cannabis use does have some adverse consequences, but overall damage to physical health is not apparent in this study.”
“Physicians should certainly explain to their patients that long-term marijuana use can put them at risk for losing some teeth,” said Terrie Moffitt, the Nannerl O. Keohane University Professor of psychology and neuroscience at Duke and co-director of the Dunedin Multidisciplinary Health and Development Study, from which these data were gathered.
Wednesday, June 1, 2016
Women with migraines have higher risk of cardiovascular disease and mortality
Women diagnosed with migraines have a slightly increased risk of developing cardiovascular diseases, such as heart attacks and strokes, and are somewhat more likely to die from these conditions than women who do not have migraine, according to findings of a large study published in The BMJ today.
These results add to evidence that migraine should be considered an important risk marker for cardiovascular disease, say experts. But more research is needed to determine possible causes, and whether treatments to prevent migraines could help to reduce these associated risks.
Migraine has been consistently linked with an increased risk of stroke, but few studies have shown an association of migraine with cardiovascular diseases and mortality.
So a team of US and German researchers carried out a large prospective study to evaluate associations between migraine, cardiovascular disease and mortality.
They analysed data from 115,541 women enrolled in the Nurses' Health Study II. The participants were aged 25-42 years, free from angina and cardiovascular disease, and followed from 1989-2011 for cardiovascular events, diseases and mortality.
Overall, 17,531 (15.2%) women reported a physician's diagnosis of migraine at baseline. Over 20 years of follow-up, 1,329 total cardiovascular disease events occurred and 223 women died due to cardiovascular disease.
When compared to women who did not have migraine, these results show that women who reported a migraine had a greater risk for major cardiovascular disease, including heart attacks, strokes and angina/coronary revascularization procedures.
These associations remained after adjusting for other factors that may have increased the risk for these diseases.
In addition, migraine was associated with a higher risk for cardiovascular mortality. This association was similar across subgroups of women, including by age, smoking status, hypertension, postmenopausal hormone therapy, and oral contraceptive use.
In a linked editorial, Rebecca Burch from Harvard Medical School and Melissa Rayhill from The State University of New York at Buffalo caution that "the magnitude of the risk should not be over-emphasized," as "it is small at the level of the individual patient, but still important at a population level because migraine is so prevalent."
While the current study controlled for a large number of vascular risk factors, no information was available for vascular biomarkers, and migraine specifics, such as migraine aura.
Nevertheless, the authors say "these results further add to the evidence that migraine should be considered an important risk marker for cardiovascular disease, at least in women," and there is no reason why the findings can't be applicable to men.
"Given the high prevalence of migraine in the general population, an urgent need exists to understand the biological processes involved and to provide preventive solutions for patients," they conclude.
The editorialists Rebecca Burch and Melissa Rayhill agree "it's time to add migraine to the list of early life medical conditions that are markers for later life cardiovascular risk."
They say this latest study raises questions about whether treatments that decrease the frequency or severity of migraine may reduce later life vascular risks, and conclude by saying "what little evidence we do have suggests the need for therapeutic restraint [to prevent cardiovascular risk] until we have a better understanding of the mechanisms underlying the link between migraine and vascular disease."
Why are blacks at higher risk for cognitive impairment?
Social and economic disadvantages play a significant role in why blacks face a much higher risk than whites of developing cognitive impairment later in life, indicates a national study led by a Michigan State University sociologist.
The odds that blacks will develop cognitive impairment, including dementia, in later life were 2.52 times greater than the odds for whites. Much of that racial disparity was explained by childhood disadvantages, such as growing up poor and in the segregated South, and lower socioeconomic status in adulthood, particularly educational attainment.
Surprisingly, racial differences in health problems, such as heart disease and diabetes, and health behaviors, such as smoking and drinking, did not explain much of the racial gap in cognitive impairment, said Zhenmei Zhang, MSU associate professor of sociology.
While the findings do not fully explain blacks' higher risk of cognitive impairment, they point to a strong need for policymakers to focus more on reducing racial gaps in socioeconomic resources over the lifespan, she said. The federally funded study is published in the Journal of Health and Social Behavior.
"Social policies such as increasing educational resources in low-income communities, providing economic support to poor students and their families, improving graduation rates in high schools and colleges, and eliminating discrimination against blacks in the job market may significantly reduce racial disparities in cognitive impairment in later life," Zhang said.
Zhang and colleagues analyzed survey data from 8,946 participants in the Health and Retirement Study. The information was collected in multiple waves over a 12-year period (1998-2010); participants were aged 65 or older at the start of the study.
Once the researchers took into account the various socioeconomic factors, which include childhood disadvantages, the odds ratio of cognitive impairment between blacks and whites - or the racial gap - was reduced considerably, from 2.52 to 1.45. That means socioeconomic factors explained a significant amount of the racial gap.
Cognitive impairment among the elderly is a growing problem - spending on dementia care alone exceeds $100 billion a year in the United States - but it hits blacks particularly hard, Zhang noted. The Alzheimer's Association has identified Alzheimer's disease among blacks as an emerging public health crisis.
"As people live longer and longer, it becomes an even bigger issue," Zhang said.
No evidence of heart damage from long-term endurance training by elite master athletes
In 2012, Belgium scientists published
a study that concluded that repeated bouts of intensive endurance exercise at
the elite level may result in the pathological enlargement of the right
ventricle, which, according to the article, is associated with potential health
hazards including sudden cardia death. The publication was the cause of
considerable debate among experts in the medical and sports communities. Sports
medicine physicians at Saarland University have now tested the conclusions of
the 2012 study by examining the hearts of elite master endurance athletes. Their
findings refute the hypothesis proposed by their Belgian colleagues. The
Saarland research team could find no evidence that years of elite-level
endurance training causes any long-term damage to the right ventricle. The
study has been published in the respected medical journal 'Circulation'.
The media reports with depressing
regularity the sudden cardiac death of endurance athletes. Just a few weeks
ago, television channels, newspapers and the internet reported that Dutch
professional cyclist Gijs Verdick had died in hospital a week after suffering a
double heart attack during a race.
The potential hazards that endurance
exercise poses to the heart have been the subject of discussion in the medical
community for over a century. Although there is now general consensus that the
enlarged heart of an athlete is a healthy reaction reflecting the adjustment of
the organ to regular endurance training, a number of studies seem to suggest
that high levels of endurance exercise can cause pathological changes to the
structure of the heart. This was the conclusion reached by a team of Belgian
cardiologists and sports medicine physicians in a study published in 2012 that
received considerable global attention.
The researchers established
a link between extreme endurance exercise training and the acute enlargement
and functional impairment of the right ventricle immediately after exercise.
More precisely, they observed enlargement and reduced functionality of the
right ventricle in athletes who had taken part in several hours of competitive
endurance sport. However, longitudinal studies have so far failed to confirm
the hypothesis formulated by the authors that endurance exercise results in
long-term damage to the right ventricle, now referred to as 'exercise-induced
arrhythmogenic right ventricular cardiomyopathy' (ARVC). It was therefore not
clear whether the acute enlargement of the right ventricle after extreme
endurance activity, which the Belgian group had identified and which had been
frequently discussed among professionals, actually did lead to a potentially
life-threatening chronic condition.
For the Saarbrücken research team led
by cardiologist and sports medicine physician Prof. Dr. Jürgen Scharhag and Dr.
Philipp Bohm, the hypothesis that endurance exercise leads to the pathological
enlargement of the right ventricle was not immediately obvious. Scientists at
the Saarbrücken Institute of Sports and Preventive Medicine have for years been
examining elite athletes from a wide variety of disciplines, including
triathletes, swimmers and professional footballers. In all that time, the
Saarbrücken researchers never found any evidence underpinning the hypothesis
posited by the Belgian team. They therefore decided to test the hypothesis
explicitly.
They examined 33 elite master
athletes (average age: 47) and compared them to a control group of 33 men who
were similar in terms of age, size and weight but who had not done any kind of
endurance exercise. The group of athletes, which included former Olympians as
well as previous Ironman participants and champions, have been training at an
elite level for around 30 years and still continue to train for an average of
about 17 hours a week.
The Saarbrücken scientists were able
to confirm that the hearts of these athletes, who have been engaged in elite
level endurance activities for many years, were, as expected, significantly
larger and stronger than those of members of the control group. 'But we found
no evidence of lasting damage, pathological enlargement or functional
impairment of either the right or left ventricle in the athletes who had been
doing long-term intensive elite-level endurance exercise,' explains Philipp
Bohm, who is now working at the Cardiology Centre at the University Hospital
Zürich.
By focusing on highly trained and active elite master athletes, the Saarbrücken research team found a clever means of circumventing a problem faced by researchers interested in these questions. Although cardiovascular magnetic resonance imaging (cardiac MRI) is the best method of examining the heart and, in particular, the right ventricle, it has not been available for very long and it is not a routine technique for examining athletes. Systematic long-term MRI-based studies of athlete hearts will therefore not be available in the foreseeable future. Data from longitudinal studies, in which subjects have been monitored by MRI for years, potentially decades, simply does not exist. 'Our cohort of elite master athletes therefore represents our best means of investigating the long-term impact of years of competition-level endurance sport,' explains Jürgen Scharhag.
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