Why you won't lose weight with exercise alone

Exercise by itself isn't always enough to take off the weight. Now, evidence reported in the Cell Press journal Current Biology on January 28 helps to explain why that is: our bodies adapt to higher activity levels, so that people don't necessarily burn extra calories even if they exercise more.

The results suggest it's time to rethink the effect of physical activity on daily energy expenditure, the researchers say. They are also a reminder of the importance of diet and exercise in supporting weight loss goals.

"Exercise is really important for your health," says Herman Pontzer of City University of New York. "That's the first thing I mention to anyone asking about the implications of this work for exercise. There is tons of evidence that exercise is important for keeping our bodies and minds healthy, and this work does nothing to change that message. What our work adds is that we also need to focus on diet, particularly when it comes to managing our weight and preventing or reversing unhealthy weight gain."

People who start exercise programs to lose weight often see a decline in weight loss (or even a reversal) after a few months. Large comparative studies have also shown that people with very active lifestyles have similar daily energy expenditure to people in more sedentary populations.

Pontzer says this really hit home for him when he was working among the Hadza, a population of traditional hunter-gatherers in northern Tanzania.

"The Hadza are incredibly active, walking long distances each day and doing a lot of hard physical work as part of their everyday life," Pontzer says. "Despite these high activity levels, we found that they had similar daily energy expenditures to people living more sedentary, modernized lifestyles in the United States and Europe. That was a real surprise, and it got me thinking about the link between activity and energy expenditure."

To explore this question further in the new study, Pontzer and his colleagues measured the daily energy expenditure and activity levels of more than 300 men and women over the course of a week.

In the data they collected, they saw a weak but measurable effect of physical activity on daily energy expenditure. But, further analysis showed that this pattern only held among subjects on the lower half of the physical activity spectrum. People with moderate activity levels had somewhat higher daily energy expenditures--about 200 calories higher--than the most sedentary people. But people who fell above moderate activity levels saw no effect of their extra work in terms of energy expenditure.

"The most physically active people expended the same amount of calories each day as people who were only moderately active," Pontzer says.

The researchers say it's time to stop assuming that more physical activity always means more calories. There might be a "sweet spot" for physical activity--too little and we're unhealthy, but too much and the body makes big adjustments in order to adapt.

Pontzer and his colleagues now plan to study how the body responds to changes in activity level. They'll start by looking for other changes--for example, in immune function or the reproductive system--that might explain how the body adapts to greater physical demands without consuming extra calories.

Cognitive training effects differ by older adult's education level

The first study to investigate the effects of cognitive training on the cognitive functioning of older adults by education level has found that individuals with fewer than 12 years of schooling benefit more from cognitive training than their more highly educated counterparts.

While the effects of reasoning and memory training did not differ by educational attainment, the effect of speed of information processing training differed significantly. Cognitively normal older adults with less than a complete high school education experienced a 50 percent greater effect from speed of information processing training than college graduates.

The advantage gained from speed of information processing training for those with fewer than 12 years of education was maintained for three years after the end of the training.

Ten trainings over six weeks on auditory and visual tasks, conveyed through specially designed computerized exercises, taught individuals to process information more quickly, and make connections in the world around them. Driving, for example, typically improves in those who have had speed of information processing training.

"Individuals who have had less education may have less cognitive reserve to overcome pathologies in the brain and may exhibit functional limitations earlier in the pathological process" said Daniel O. Clark, Ph.D., the social epidemiologist who led the new study. "Those starting out at lower education levels had more room for improvement."

Dr. Clark is an Indiana University Center for Aging Research and Regenstrief Institute investigator, director of research and development at Sandra Eskenazi Center for Brain Care Innovation at Eskenazi Health, and an IU School of Medicine associate professor of medicine.

Evidence suggests that one-third to one-half of Alzheimer's disease cases worldwide may be attributed to potentially modifiable risk factors. Recent estimates of these population-attributable risks for Alzheimer's disease identify low educational attainment as one of the most significant of seven modifiable risk factors that also include depression, physical inactivity and smoking.

"Although not achieving early life education beyond secondary school creates a risk for earlier onset of Alzheimer's disease or other dementias, it may not be associated with a faster rate of cognitive decline," Dr. Clark said.

Data for the study led by Dr. Clark was obtained from the approximately 2,800 cognitively normal individuals age 65 and older of all education levels who participated in the multi-center Advanced Cognitive Training for Independent and Vital Elderly (ACTIVE) study, which explored whether cognitive training in memory, reasoning, and speed of information processing affected cognitively based measures of daily functioning. The ACTIVE study found that reasoning and information processing speed training, but not memory training, resulted in improved targeted cognitive abilities for 10 years.

Less educated study participants were slightly older, less likely to be married, and more likely to be African-American. The less educated also were more likely to have hypertension or diabetes as well as heart disease than the more educated older adults.

"If you practice some cognitive skills, you certainly will improve on those skills you are practicing," Dr. Clark said. "The question remains open, however, as to how much will those practiced and improved skills transfer to daily cognitive function. And the big question is whether they will delay the onset of dementia."

"There is tremendous interest in nonpharmacological and self-help approaches that well older adults can engage in to help modify - that is reduce - their risk for later onset of cognitive decline and even dementia," said Frederick W. Unverzagt, Ph.D., professor of psychiatry at IU School of Medicine and principal investigator of the Indianapolis field site of the ACTIVE study. "This paper takes an important step toward identifying subgroups of people who may stand to benefit most from these types of interventions."

Dr. Clark, whose research interests include modification of disease risk factors, hopes to conduct a future study of older adults with little education randomized to cognitive training or no training to confirm that speed of processing training is as effective as it appears to be for those with less than a high school degree.

Attitude to aging can have a direct effect on health

Negative attitudes to ageing affect both physical and cognitive health in later years, new research reveals. The study from the Irish Longitudinal Study on Ageing (TILDA), at Trinity College Dublin, further reveals that participants with positive attitudes towards ageing had improved cognitive ability.

Key findings:

·      Older adults with negative attitudes towards ageing had slower walking speed and worse cognitive abilities two years later, compared to older adults with more positive attitudes towards ageing.

·      This was true even after participants' medications, mood, their life circumstances and other health changes that had occurred over the same two-year period were accounted for.

·      Furthermore, negative attitudes towards ageing seemed to affect how different health conditions interacted. Frail older adults are at risk of multiple health problems including worse cognition. In the TILDA sample frail participants with negative attitudes towards ageing had worse cognition compared to participants who were not frail. However frail participants with positive attitudes towards ageing had the same level of cognitive ability as their non-frail peers.

Speaking about the findings, lead researcher Dr Deirdre Robertson commented: "The way we think about, talk about and write about ageing may have direct effects on health. Everyone will grow older and if negative attitudes towards ageing are carried throughout life they can have a detrimental, measurable effect on mental, physical and cognitive health."

Principal Investigator of TILDA, Professor Rose Anne Kenny, added: "Researchers and policy makers can work together to develop and implement societal-wide interventions to target attitudes and perhaps, ultimately, find novel ways of maintaining health in later life."

Data from TILDA provides a unique opportunity to study attitudes towards ageing as it tracks health changes over time in a nationally representative sample of community-dwelling older adults.

These latest findings have important implications for media, policymakers, practitioners and society more generally. Societal attitudes towards ageing are predominantly negative. Everyone will grow older and if these attitudes persist they will continue to diminish quality of life.

Sedentary lifestyle spells more menopause misery

Sedentary middle-aged Hispanic women in Latin America have significantly worse menopause symptoms than their active counterparts, shows a study of more than 6,000 women across Latin America, which was published online today in Menopause, the journal of The North American Menopause Society (NAMS). The analysis also linked sedentary lifestyle with depression, anxiety, insomnia, and obesity.

The study analyzed data from the Collaborative Group for Research of the Climacteric in Latin America surveys and health records of 6,079 women, ages 40 to 59, who attended one of 20 urban health centers in 11 Latin American countries. The women completed standard questionnaires about depression, anxiety, insomnia, and menopause symptoms. Symptoms on the Menopause Rating Scale (MRS) questionnaire include somatic symptoms, such as hot flashes and joint pains, psychological symptoms such as depressed mood and anxiety, and urogenital symptoms such as sexual problems, vaginal dryness, and bladder problems. The women also answered other questions, such as what their activity level and menopause status were.

Women were considered to be sedentary if they reported fewer than 3 weekly sessions of physical activity, such as walking, jogging, or swimming, that lasted 30 minutes or longer, and menopause symptoms were considered severe if the MRS score was 16 or more.

A sedentary lifestyle was very common, reported by 64% of the women. And the following statistically significant contrasts between the sedentary women and active women stood out: Some 16% of the sedentary women had severe menopause symptoms compared with 11% of the active women. The sedentary women also had higher total menopause scores, and more of them had any of the individual symptoms than the active women did. The sedentary women were also more likely to be obese and to have higher scores on the depression, anxiety, and insomnia scales.

Results of studies of the ability of exercise to reduce menopause symptoms have been conflicting, but this study adds some weight to the exercise side of the equation.

Less menopause misery is just one of the positive impacts of being active for women at midlife, emphasizes NAMS Executive Director JoAnn V. Pinkerton, MD, NCMP.

"Regular physical activity reduces the risk of breast and colon cancer, dementia, heart attacks, stroke, depression; loss of lean muscle mass, and bone loss and improves immune system function. One study showed that just one hour of walking daily cut the risk of obesity by 24%. Fewer hot flashes, fewer health risks, increased well-being--who doesn't want these benefits?"

Eating soy may protect women from health risks of BPA

Consuming soy regularly may protect women who are undergoing infertility treatments from poor success rates linked to bisphenol A exposure, according to a new study published in the Endocrine Society's Journal of Clinical Endocrinology & Metabolism.

Bisphenol A (BPA) is a chemical found in a variety of food containers, including polycarbonate plastic water bottles and can linings. BPA can mimic estrogen, one of the two main sex hormones found in women. Biomonitoring studies by the U.S. Centers for Disease Control and Prevention estimate that more than 96 percent of Americans have BPA in their bodies.

As of 2014, nearly 100 epidemiological studies have been published tying BPA to health problems, including reproductive disorders, according to the Society and IPEN's Introductory Guide to Endocrine-disrupting Chemicals.

"Our study is the first to show a possible interaction between soy and BPA in humans," said first author Jorge E. Chavarro, MD, ScD, of Harvard T.H. Chan School of Public Health, Brigham and Women's Hospital, and Harvard Medical School in Boston, MA. "This is consistent with research in mice that found a soy-rich diet could protect against reproductive health problems associated with BPA exposure. More research is needed to determine why soy has this effect in humans."

The researchers examined the relationship between BPA exposure, diet and success rates among 239 women who underwent at least one in vitro fertilization (IVF) cycle at the Massachusetts General Hospital Fertility Center between 2007 and 2012. The women participated in the Environment and Reproductive Health (EARTH) Study, an ongoing prospective cohort study designed to evaluate the role of environmental factors and nutrition in fertility. The EARTH Study was funded by the National Institutes of Health's National Institute of Environmental Health Sciences.

Participants' urine samples were analyzed to measure BPA exposure. The women, who were between the ages of 18 and 45, completed a lifestyle questionnaire that included questions about how frequently they ate soy-based foods. Among the participants, 176 consumed soy foods.

Among women who did not eat soy foods, those with higher levels of BPA in their urine had lower rates of embryo implantation, fewer pregnancies that progressed to the point where the fetus could be seen on an ultrasound, and fewer live births than women with lower levels of BPA in their bodies. In comparison, BPA concentrations had no impact on IVF outcomes in women who routinely ate soy.

"Although it is recommended that women trying to get pregnant reduce their exposure to BPA, our findings suggest that diet may modify some of the risks of exposure to BPA, a chemical that is nearly impossible to completely avoid due to its widespread use," said senior author Russ Hauser, MD, ScD, MPH of Harvard T.H. Chan School of Public Health, Massachusetts General Hospital, Harvard Medical School in Boston, MA.

"Additional research could help identify other diet and lifestyle changes that may modify the effects of not only BPA exposure, but also exposure to other chemicals," Chavarro added. "In order to fully appreciate risks to human health, we need to design studies that adequately assess both diet and environmental chemical exposures."

Flavonoids from fruits and vegetables may help with weight maintenance

Eating fruit and vegetables that contain high levels of flavonoids, such as apples, pears, and berries, may be associated with less weight gain, suggests findings from a study published in The BMJ.

Dietary flavonoids are natural compounds found in fruits and vegetables. These have been linked to weight loss, but most studies have looked at a particular flavonoid found in green tea, and have mostly been limited to small samples.

So a team of researchers examined the association between the dietary intake of seven flavonoid subclasses and weight change in a large study of 124,086 men and women based across the US over 24 years.

They tracked participants who were part of three prospective cohort studies: the Health Professionals Follow Up Study, Nurses' Health Study, and Nurses' Health Study II.

Participants self-reported their weight, lifestyle habits, and any recently diagnosed diseases via questionnaire every two years, between 1986 and 2011. In addition, they self reported their diet every four years.

Findings revealed that increased consumption of flavonoid subclasses was associated with less weight gain.

The greatest association was found for anthocyanins, flavonoid polymers, and flavonols: each greater standard deviation of daily intake was associated with 0.16 to 0.23 lbs (equivalent to 0.07- 0.10 kg) less weight gained over four year intervals.

Blueberries and strawberries were the main source of anthocyanins, and flavan-3-ols and their polymers were mainly derived from tea and apples. Orange juice and oranges were the main sources of flavanone and flavones, and tea and onions were the main sources of flavonols.

The study adjusted for a range of dietary and lifestyle factors that may have influenced the results, such as smoking status and physical activity. Results were consistent across men and women, and different ages.

This is the first study to examine the associations between consumption of seven flavonoid subclasses and weight gain in a large sample size.

It is an observational study so no definite conclusions can be made, and several limitations exist due to the design of the study. Nevertheless, the authors say that the findings "may help to refine previous dietary recommendations for the prevention of obesity and its potential consequences."

In addition, they say that losing or preventing even small amounts of weight can reduce risk of diabetes, cancer, hypertension and cardiovascular disease. They add that the results can provide guidance on which fruits and vegetables to choose for preventing weight gain.

In the US, for example, most people consume less than one cup of fruits, and less than two cups of vegetables daily. The authors suggest that this should be increased to two cups of fruits, and two and a half cups of vegetables.

Furthermore, they add that people may be able to maximize the health benefits of eating fruit and vegetables by choosing those with high levels of flavonoids, such as apples, pears, and berries.

High protein diet = better results

Researchers at McMaster University have uncovered significant new evidence in the quest for the elusive goal of gaining muscle and losing fat, an oft-debated problem for those trying to manage their weight, control their calories and balance their protein consumption.

Scientists have found that it is possible to achieve both, and quickly, but it isn't easy.

For the study, 40 young men underwent a month of hard exercise while cutting dietary energy they would normally require by 40 per cent of what they would normally require.

"It was a gruelling affair," says Stuart Phillips, a professor in the Department of Kinesiology at McMaster and senior investigator on the study. "These guys were in rough shape, but that was part of the plan. We wanted to see how quickly we could get them into shape: lose some fat, but still retain their muscle and improve their strength and fitness," he says.

The researchers divided their subjects into two groups. Both groups went on a low calorie diet, one with higher levels of protein than the other. The higher-protein group experienced muscle gains -- about 2.5 pounds -- despite consuming insufficient energy, while the lower protein group did not add muscle.

The lower-protein group at least had the consolation of not losing muscle, which is a predictable outcome of cutting calories and not working out, say researchers.

"Exercise, particularly lifting weights, provides a signal for muscle to be retained even when you're in a big calorie deficit," says Phillips.

Researchers were intrigued because the high-protein group also lost more body fat.

"We expected the muscle retention" said Phillips, "but were a little surprised by the amount of additional fat loss in the higher protein consuming group."

The results showed that the high-protein group lost about 10.5 pounds and the low protein group only eight pounds. All of the participants, by virtue of the demanding six-days-a-week exercise routines, got stronger, fitter, and generally were in much better shape.

However, researchers caution this regimen is not for everyone.

"We designed this program for overweight young men, although I'm sure it would work for young women too, to get fitter, stronger, and to lose weight fast. It's a tough program and not something that's sustainable or for those looking for quick and easy fix," says Phillips. "We controlled their diets, we supervised the exercise, and we really kept these guys under our 'scientific' thumb for the four weeks the participants were in the study."

Phillips and his team hope to conduct a follow-up study on women and also explore a different approach that he says will be "a little easier and much more sustainable."

The study was published in the latest issue of the American Journal of Clinical Nutrition.

Zinc supplement boosted serum zinc levels and immunity in older adults

The immune system weakens as the body ages, making older adults more susceptible to infections. Low levels of zinc impair immunity, particularly in older adults. A research team set out to determine if it was feasible to increase serum zinc concentrations in older adults in nursing homes who were zinc-deficient. Their work appears in The American Journal of Clinical Nutrition.

"Our previous work showed that 30 percent of nursing home residents have low serum zinc levels and those with low serum zinc levels had a significantly higher incidence of pneumonia and morbidity from it. Our new finding that serum zinc levels can be improved in older adults with zinc supplementation and that this is associated with enhancement of T-cell numbers and function strongly suggests that ensuring adequate zinc consumption by older adults could have a significant impact on reducing the incidence of and morbidity from infection, which is a major public health problem in older adults," said the study's lead author, Simin Nikbin Meydani, D.V.M., Ph.D., the director of the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University in Boston, and senior scientist and director of its Nutritional Immunology Laboratory.

The small double-blind, placebo-controlled trial involved adults age 65 or older from three Boston-area nursing homes. The study participants had baseline serum levels of zinc that ranged from moderately to very zinc-deficient. Participants were given zinc supplements or a placebo for three months. A total of 25 people completed the study, with 13 receiving the placebo (a daily multi-vitamin with only 5 mg of zinc), and 12 receiving a daily multi-vitamin with 30 mg of zinc. A serum-level of 70 micrograms per deciliter was used as the cut-off standard for adequate serum zinc level and measuring improvement from supplementation. The function of the immune response was assessed by determining the immune cell profile and function.

In addition to serum zinc concentrations, the researchers found that zinc supplementation improved the function of T-cells as determined by their ability to proliferate in response to stimuli that mimicked infection. Furthermore, they saw a positive correlation between serum zinc levels and the number and function of T-cells. This effect of zinc was attributed to increasing the number of T-cells rather than enhancing the function of each T-cell. At the end of three months, researchers found that:

• Zinc supplementation increased serum zinc concentrations in nursing home residents with low zinc levels.
• Zinc supplementation increased both the number and effectiveness of T-cells in the treatment group at a much higher rate than the control group
• The increase of serum zinc rose higher in the treatment group, at a rate of 16 percent, compared to those in the control group, which rose at a rate of 0.7 percent.
• For those in the treatment group who were moderately zinc-sufficient at baseline, their serum zinc levels exceeded the cut-off standard.
• Participants in the treatment group whose serum levels were measured as substantially zinc-deficient at baseline did not experience an increase to normal levels during the trial.

"Having a positive response to zinc supplementation may take some time in people who have been highly zinc deficient. We need to better understand how much supplementation is needed for certain people, and for how long a period, so that more refined recommendations can be made," added first author Junaidah B. Barnett, M.C.H. (N), Ph.D., scientist in the Nutritional Immunology Laboratory at the HNRCA.

"It is worth noting that zinc deficiency is not just a problem in nursing home residents; it also exists in non-institutionalized older adults," Meydani continued. "On average, zinc supplementation measurably improved serum zinc levels in these older adults, with most participants achieving serum zinc levels considered to be adequate."

Zinc is found in a wide variety of foods, including oysters, pork, red meat, poultry, seafood, and fortified breakfast cereals. Zinc is also found in beans, nuts, whole grains, cucumber peel, and dairy products and is common in multi-vitamins. The Office of Dietary Supplements of the National Institutes of Health notes that zinc deficiency is rare in North America, but that some groups of people are more likely to have trouble getting enough zinc, including those with digestive disorders and vegetarians. Too much zinc (the upper limit for adults is 40 mg/day) can be harmful. Some researchers suspect, however, the older adults do not absorb or use zinc as efficiently as others. In addition, while serum zinc levels are a commonly used measure to evaluate zinc deficiency, they might not accurately reflect cellular zinc status. Some cells might exhibit low zinc levels, which impacts their function, even when serum zinc levels are normal.

American Heart Association makes first ever statement on female heart attacks

A woman's heart attack causes, symptoms may differ from a man's
American Heart Association Scientific Statement

AMERICAN HEART ASSOCIATION

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DALLAS, Monday, January 25, 2016 --A woman's heart attack may have different underlying causes, symptoms and outcomes compared to men, and differences in risk factors and outcomes are further pronounced in black and Hispanic women, according to a scientific statement published in the American Heart Association's journal Circulation.

The statement is the first scientific statement from the American Heart Association on heart attacks in women. It notes that there have been dramatic declines in cardiovascular deaths among women due to improved treatment and prevention of heart disease as well as increased public awareness.

"Despite stunning improvements in cardiovascular deaths over the last decade, women still fare worse than men and heart disease in women remains underdiagnosed, and undertreated, especially among African-American women," said writing group chair Laxmi Mehta, M.D., a noninvasive cardiologist and Director of the Women's Cardiovascular Health Program at The Ohio State University.

Causes:

Heart attacks caused by blockages in the main arteries leading to the heart can occur in both men and women. However, the way the blockages form a blood clot may differ. Compared to men, women can have less severe blockages that do not require any stents; yet the heart's coronary artery blood vessels are damaged which results in decreased blood flow to the heart muscle. The result is the same - when blood flow to the heart is decreased for any reason, a heart attack can occur. If doctors don't correctly diagnose the underlying cause of a woman' heart attack, they may not be prescribing the right type of treatments after the heart attack. Medical therapies are similar regardless of the cause of the heart attack or the severity of the blockages. However women are undertreated compared to men despite proven benefits of these medications.

Treatment:

Women face greater complications from attempts to restore blood flow because their blood vessels tend to be smaller, they are older and have increased rates of risk factors, such as diabetes and high blood pressure. Guideline recommended medications are consistently underutilized in women leading to worse outcomes. Also, cardiac rehabilitation is prescribed less frequently for women and even when it is prescribed, women are less likely to participate in it or complete it.

Symptoms:

While the most common heart attack symptom is chest pain or discomfort for both sexes, women are more likely to have atypical symptoms such as shortness of breath, nausea or vomiting, and back or jaw pain.

Risk factors:

Risk factors for heart attacks also differ in degree of risk in men compared to women. For example, high blood pressure is more strongly associated with heart attacks in women and if a young woman has diabetes her risk for heart disease is 4 to 5 times higher compared to young men.

Racial differences:

Compared to white women, black women have a higher incidence of heart attacks in all age categories and young black women have higher in-hospital death rates. Black and Hispanic women tend to have more heart- related risk factors such as diabetes, obesity and high blood pressure at the time of their heart attack compared to non-Hispanic white women. Compared to white women, black women are also less likely to be referred for important treatments such as cardiac catheterization..

Understanding gender differences can help improve prevention and treatment among women. "Women should not be afraid to ask questions - we advise all women to have more open and candid discussions with their doctor about both medication and interventional treatments to prevent and treat a heart attack," Mehta said.

"Coronary heart disease afflicts 6.6 million American women annually and remains the leading threat to the lives of women. Helping women prevent and survive heart attacks through increased research and improving ethnic and racial disparities in prevention and treatment is a public health priority," she said.

Fiber protects against heart disease, diabetes, lung disease

A diet rich in fiber may not only protect against diabetes and heart disease, it may reduce the risk of developing lung disease, according to new research published online, ahead of print in the Annals of the American Thoracic Society.

Analyzing data from the National Health and Nutrition Examination Surveys, researchers report in "The Relationship between Dietary Fiber Intake and Lung Function in NHANES," that among adults in the top quartile of fiber intake:

• 68.3 percent had normal lung function, compared to 50.1 percent in the bottom quartile.
• 14. 8 percent had airway restriction, compared to 29.8 percent in the bottom quartile.

In two important breathing tests, those with the highest fiber intake also performed significantly better than those with the lowest intake. Those in the top quartile had a greater lung capacity (FVC) and could exhale more air in one second (FEV1) than those in the lowest quartile.

"Lung disease is an important public health problem, so it's important to identify modifiable risk factors for prevention," said lead author Corrine Hanson PhD, RD, an associate professor of medical nutrition at the University of Nebraska Medical Center. "However, beyond smoking very few preventative strategies have been identified. Increasing fiber intake may be a practical and effective way for people to have an impact on their risk of lung disease."

Researchers reviewed records of 1,921 adults, ages 40 to 79, who participated in NHANES during 2009-2010. Administered by the Centers for Disease Control and Prevention, NHANES is unique in that it combines interviews with physical examinations.

Fiber consumption was calculated based on the amount of fruits, vegetables, legumes and whole grains participants recalled eating. Those whose diets included more than 17.5 grams of fiber a day were in the top quartile and represented the largest number of participants, 571. Those getting less than 10.75 grams of fiber a day were in the lower group and represented the smallest number of participants, 360.

Researchers adjusted for a number of demographic and health factors, including smoking, weight and socioeconomic status, and found an independent association between fiber and lung function. They did not adjust for physical activity, nor did the NHANES data allow them to analyze fiber intake and lung function over time -- limitations acknowledged by the authors.

Authors cited previous research that may explain the beneficial effects of fiber they observed. Other studies have shown that fiber reduces inflammation in the body, and the authors noted that inflammation underlies many lung diseases. Other studies have also shown that fiber changes the composition of the gut microbiome, and the authors said this may in turn reduce infections and release natural lung-protective chemicals to the body.

If further studies confirm the findings of this report, Hanson believes that public health campaigns may one day "target diet and fiber as safe and inexpensive ways of preventing lung disease."

Intensive exercise with intervals 'more effective'

Short bursts of intensive exercise provide a more "time-efficient" and realistic way of preventing, delaying and managing Type 2 diabetes and also losing weight, a study has found.

Small amounts of vigorous activity in quick successions are more "effective" compared to longer forms of exercise optimising the body's ability to use and store blood sugar, the research by the University of Leicester and the NIHR Leicester-Loughborough Diet, Lifestyle and Physical Activity Biomedical Research Unit (BRU) has found.

The paper 'The effects of high-intensity interval training on glucose regulation and insulin resistance: a meta-analysis' has been published in the journal Obesity Reviews.

Obesity and Type 2 diabetes are linked, with over 80 per cent of people with the condition classed as overweight or obese -- diet and physical activity interventions are the cornerstones for management of both conditions.

The effects of exercise on Type 2 diabetes and improving the body's ability to use insulin to absorb blood sugar are well established, but its impact on weight regulation is more controversial.

The guidelines for weight loss suggest that 200 to 300 minutes of moderate to vigorous activity per week are required for long-term reductions, but previous research found that only five per cent of people in some industrialised countries achieve this amount. Recently, however, effects of physical activity on health in the absence of weight loss, have emerged.

In response, the study has proposed high-intensity interval training (HIIT) as an alternative: "time-efficient exercise intervention that may bring about similar benefits to moderate-intensity aerobic exercise."

Researcher Charlotte Jelleyman said: "This study involved a meta-analysis of experimental research, allowing us to pull together evidence and establish cause and effect. We have demonstrated that HIIT conveys benefits to cardiometabolic health which in the cases of insulin resistance and aerobic fitness may be superior to the effect of traditional continuous training.

"HIIT may therefore be suitable as an alternative to continuous exercise training in the promotion of metabolic health and weight loss, particularly in those with Type 2 diabetes or metabolic syndrome. However, given the identified limitations, more research is needed to determine both behavioural responses and clinical benefits over the longer term."

The NIHR Leicester-Loughborough Diet, Lifestyle and Physical Activity BRU is a national centre of excellence in diet, lifestyle and physical activity based in Leicester and Loughborough. It harnesses the power of experimental science to explore and develop ways to help prevent and treat chronic disease.

Vegetables fried with olive oil have more healthy properties than boiled ones

Researchers from the University of Granada (UGR) have proven that frying in Extra Virgin Olive Oil (EVOO) is the cooking method that increases the phenolic fraction present in raw vegetables used in Mediterranean diet (potato, pumpkin, tomato and eggplant) the most. This means an improvement to this foods in the cooking process.

In an article published in Food Chemistry magazine, researchers have proven that vegetables fried in EVOO improved their antioxidant capacity and the amount of phenolic compounds, which prevent chronic degenerative pathologies such as cancer, diabetes or macular degeneration.

The aim of this research was to determine the effect of applying various cooking methods on the antioxidant capacity and the amount of phenolic compounds (total and individual concentrations) present in vegetables consumed in the Mediterranean diet.

The Mediterranean diet of the Spanish population is characterized by a high intake of vegetables and EVOO. These are both an important source of dietary phenols, whose consumption has been associated with the prevention of chronic degenerative pathologies. This kind of antioxidants can be modified during the processing of the foods, increasing or decreasing their concentrations.

With this goal in mind, the researchers conceived an experiment in which they cooked 120 grams cubes of potato (Solanumtuberosum), pumpkin (Cucurbitamoschata), tomato (Licopersicumesculentum) and eggplant (Solanummelongena), all of them without seeds or skin.

Fried, boiled, or with a mix of water and EVOO
 
The vegetables were fried and sautéed in EVOO, boiled in water, and boiled in a mix of water and EVOO. The experiments were controlled so the processing conditions were guaranteed. The ratio between vegetable and cooking element was constant, following traditional Spanish recipes.
Processed vegetables were kept in right conditions for the measurement of moisture, fat, dry matter and total number of phenols, as well as the measurement of the antioxidant capacity, by various methods. Parallel to this, the research was completed with the determination of the content in individual phenolic compounds typical of each vegetable, using high-performance liquid chromatography (HPLC).

The results showed that using EVOO for frying vegetables increases their fat content and reduces their moisture, while this is not observed in other cooking methods.

"Comparing the content of phenols with that of raw vegetables we found increases and reductions alike, depending on the chosen method. Oil as a mean of heat transfer increases the amount of phenolic compounds in vegetables, opposite to other cooking methods such as boiling, where heat transfer is done through the water", explains one of the authors of this paper, professor Cristina Samaniego Sánchez from UGR.

EVOO transfers phenols to the vegetables
 
This is due to a transfer of phenols from EVOO to the vegetables, enhancing the latter with oil-exclusive phenolic compounds which are not naturally present in raw vegetables.

"Therefore, we can confirm that frying is the method that produces the greatest associated increases in the phenolic fraction, which means an improvement in the cooking process although it increases the energy density by means of the absorbed oil", says Samaniego.

All the cooking methods increased the antioxidant capacity of all four vegetables. It was a reduction of it or an absence of significant changes after boiling them in water, in certain cases.

Samaniego stresses that each cooked vegetable developed a specific profile of phenols, moisture, fat, dry matter and antioxidant activity determined by the original characteristics of the raw vegetables and the cooking method applied.

"When the phenolic content of the raw vegetable is high, the total content of phenols is increased even more if EVOO is used in the process, and boiling doesn't affect the final concentration. Therefore, we must stress that frying and sautéing conserve and enhance the phenolic composition. Hydrothermal cooking methods can be recommended when the food is consumed together with the cooking water, as the addition of EVOO improves the phenolic profile and compensates for the deficiencies of the raw food", the researcher stresses.

Exercise for people with dementia improves balance and reduces dependence

Regular exercise improves balance for people with dementia and reduces dependence on assistance. This according to new research on healthcare for people suffering from dementia conducted at Umeå University in Sweden, which has now been published in the Journal of the American Geriatrics Society.

In a unique study on people with dementia living in residential care facilities, researchers from Umeå University have found that regular functional exercise, similar to everyday activities and performed at high intensity, can improve balance and reduce dependence on assistance in activities of daily living, such as for instance mobility or toilet visits. Training sessions lasting 45 minutes, two to three times per week, can lead to an improved quality of life for individuals suffering from dementia - a progressive illness leading to gradual reduction in cognitive and physical function.

In 2012, the number of individuals with dementia in Sweden stretched to 150,000 according to the National Board of Health and Welfare (Socialstyrelsen). This is a number expected to reach at least 250,000 in 2050 at the speed of population ageing. Having an increased proportion of individuals with dementia in society increases the demand and costs for healthcare. At present, the cost of dementia in Sweden reaches around SEK 60 billion per annum, according to the National Board of Health and Welfare.

"Regular exercise has a positive effect on people with dementia and should, therefore, be included in the care in residential care facilities. Studies such as the present one are rare, but provide important knowledge to further build upon in order to develop care of people with dementia as a cost-effective means of meeting future challenges, and help individuals to maintain independence longer," says Annika Toots, PhD student at the Department of Community Medicine and Rehabilitation at Umeå University, and first author of the article.

The study, described in the article Effects of a high-intensity functional exercise program on dependence in activities of daily living and balance in older adults with dementia, is a part of the greater Umeå Dementia and Exercise Study (UMDEX), performed involving people with dementia in residential care facilities. As a next step, research groups at the Unit of Physiotherapy and Geriatric medicine will analyse which effect exercise has on for instance ability to walk and cognitive ability in the target group, as well as how participants and physiotherapists experienced the exercise programme.

The published study involved 186 people with dementia in 16 different residential care facilities in the Umeå area. All participants were 65 years of age or above and in need of personal care. The participants were randomly allocated into two groups, where one group undertook a high-intensive, functional exercise programme led by physiotherapists. The programme included various functional exercises that aimed to improve leg strength, balance and walking, which are part of everyday activities. The workout covered 45 minutes, two to three times per week for a duration of four months.

Instead of training, the sedentary control group took part in stimulating activities of group conversations, singing and reading aloud sessions. The purpose of this was to control the positive effects that stimulation through togetherness and attention have. All participants were tested before, as well as four and seven months after the completion of the programme.

Due to the progressive course of dementia, a deterioration was noted in all participants' abilities to independently manage everyday activities. The deterioration occurred at a slower pace in the exercise group and they showed an improved balance. The positive effects of the exercise varied depending on the type of dementia, where the group with vascular dementia experienced better effects of exercising than participants with Alzheimer's disease. To better plan and carry out exercise for people with dementia, it can, therefore, be of importance to identify the type of dementia.

'Peanut butter' test can help diagnose Alzheimer's disease

A dollop of peanut butter and a ruler can be used to confirm a diagnosis of early stage Alzheimer’s disease, University of Florida Health researchers have found.

Jennifer Stamps, a graduate student in the UF McKnight Brain Institute Center for Smell and Taste, and her colleagues reported the findings of a small pilot study in the Journal of the Neurological Sciences.

Stamps came up with the idea of using peanut butter to test for smell sensitivity while she was working with Dr. Kenneth Heilman, the James E. Rooks distinguished professor of neurology and health psychology in the UF College of Medicine’s department of neurology.

She noticed while shadowing in Heilman’s clinic that patients were not tested for their sense of smell. The ability to smell is associated with the first cranial nerve and is often one of the first things to be affected in cognitive decline. Stamps also had been working in the laboratory of Linda Bartoshuk, the William P. Bushnell presidentially endowed professor in the College of Dentistry’s department of community dentistry and behavioral sciences and director of human research in the Center for Smell and Taste.

“Dr. Heilman said, ‘If you can come up with something quick and inexpensive, we can do it,’” Stamps said.

She thought of peanut butter because, she said, it is a “pure odorant” that is only detected by the olfactory nerve and is easy to access.

In the study, patients who were coming to the clinic for testing also sat down with a clinician, 14 grams of peanut butter — which equals about one tablespoon — and a metric ruler. The patient closed his or her eyes and mouth and blocked one nostril. The clinician opened the peanut butter container and held the ruler next to the open nostril while the patient breathed normally. The clinician then moved the peanut butter up the ruler one centimeter at a time during the patient’s exhale until the person could detect an odor. The distance was recorded and the procedure repeated on the other nostril after a 90-second delay.

The clinicians running the test did not know the patients’ diagnoses, which were not usually confirmed until weeks after the initial clinical testing.

The scientists found that patients in the early stages of Alzheimer’s disease had a dramatic difference in detecting odor between the left and right nostril — the left nostril was impaired and did not detect the smell until it was an average of 10 centimeters closer to the nose than the right nostril had made the detection in patients with Alzheimer’s disease. This was not the case in patients with other kinds of dementia; instead, these patients had either no differences in odor detection between nostrils or the right nostril was worse at detecting odor than the left one.

Of the 24 patients tested who had mild cognitive impairment, which sometimes signals Alzheimer’s disease and sometimes turns out to be something else, about 10 patients showed a left nostril impairment and 14 patients did not. The researchers said more studies must be conducted to fully understand the implications.

“At the moment, we can use this test to confirm diagnosis,” Stamps said. “But we plan to study patients with mild cognitive impairment to see if this test might be used to predict which patients are going to get Alzheimer’s disease.”

Stamps and Heilman point out that this test could be used by clinics that don’t have access to the personnel or equipment to run other, more elaborate tests required for a specific diagnosis, which can lead to targeted treatment. At UF Health, the peanut butter test will be one more tool to add to a full suite of clinical tests for neurological function in patients with memory disorders.

One of the first places in the brain to degenerate in people with Alzheimer’s disease is the front part of the temporal lobe that evolved from the smell system, and this portion of the brain is involved in forming new memories.

“We see people with all kinds of memory disorders,” Heilman said. Many tests to confirm a diagnosis of Alzheimer’s disease or other dementias can be time-consuming, costly or invasive. “This can become an important part of the evaluation process.”

Regular exercise critical for heart health, longevity

The majority of citizens in developed countries should not be concerned by potential harm from exercise but rather by the lack of exercise in their lives, according to a clinical perspective published today in the Journal of the American College of Cardiology from the ACC Sports and Exercise Cardiology Leadership Council. According to the council, small amounts of physical activity, including standing, are associated with a lower risk of cardiovascular disease, but more exercise leads to even greater reduction in risk of death from cardiovascular disease.

"The evidence with regard to exercise continues to unfold and educate the cardiovascular clinical community," said JACC Editor-in-Chief Valentin Fuster, M.D., Ph.D. "The greatest benefit is to simply exercise, regardless of the intensity, while the danger is two-fold: to not exercise at all or to exercise intensely, without due preparation."

Studies have shown that regular physical activity reduces a person's risk of death from cardiovascular disease; however, only half of U.S. adults meet the federally recommended guidelines of 150 minutes per week of moderate intensity exercise or 75 minutes per week of vigorous intensity exercise.

In this report, the American College of Cardiology Sports and Exercise Cardiology Council examined recent research on the volume and intensity of aerobic exercise required for favorable cardiovascular health. With the rise in participation in endurance races over the past three decades, they also address the question of whether or not there is an amount of exercise that increases cardiovascular disease risk.

The council found that moderate and vigorous intensity exercise in amounts lower than the 2008 Physical Activity Guideline recommendations still significantly lower mortality risk in different populations around the globe. Increasing the amount of moderate intensity exercise a person engages in results in increased reductions in cardiovascular disease mortality; however, the reductions in cardiovascular mortality benefits from vigorous intensity exercise do level out at a certain point.

There is no evidence for an upper limit to exercise-induced health benefits and all amounts of both moderate and vigorous intensity exercise result in a reduction of both all-cause and cardiovascular disease mortality compared to physical inactivity.

While controversial, a few limited studies have raised the concern that high volumes of aerobic exercise may be as bad for cardiovascular outcomes as no exercise at all. According to the council, the possibility that too much exercise training could be harmful is worthy of investigation, but research results show that even for the very active, life-long endurance athletes, the benefits of exercise training outweigh the risks.

"The public media has embraced the idea that exercise may harm the heart and disseminated this message, thereby diverting attention away from the benefits of exercise as a potent intervention for the primary and secondary prevention of heart disease," said Michael Scott Emery, M.D., co-chair of the ACC Sports and Exercise Cardiology Council.

For cardiovascular disease patients, exercise can save lives, but one study showed that only 62 percent of heart attack patients were referred to cardiac rehabilitation at hospital discharge. Of those, just 23 percent attended more than one rehab session and only 5.4 percent completed more than 36 sessions.

"The available evidence should prompt clinicians to recommend strongly low and moderate exercise training for the majority of our patients," Emery said. "Equally important are initiatives to promote population health at large through physical activity across the life span, as it modulates behavior from childhood into adult life."

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Eradicating B12 deficiency for the elderly is as simple as screening for it

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New research published in Applied Physiology, Nutrition, and Metabolism reveals that a high proportion of long-term care residents have a B12 deficiency. Researchers from the University of Waterloo and the Schlegel-University of Waterloo Research Institute for Aging found that the current state of B12 levels for elderly individuals in long-term care facilities in Ontario warrants considering B12 screening at admission in order to ensure effective treatment

Currently, prospective long-term care residents are not systematically screened for a B12 deficiency at admission and in some situations not screened unless the individual has symptoms to suggest that they are anemic. However, B12 is linked with many health issues such as depression and dementia and even suboptimal levels of the vitamin can have negative side effects on cognition, function and quality of life. Screening for deficiency is an especially important practice for older adults who are commonly B12 deficient as a result of medications that interfere with the vitamin's absorption

The research published today in Applied Physiology, Nutrition, and Metabolism looked at eight long-term care facilities in Ontario, finding that 14% of residents displayed a B12 deficiency at admission with another third of study participants having a lower than optimal B12 status. During the year after admission 4% of residents developed a deficiency, while those who received treatment had improved B12 levels. This study is the first step in providing an accurate estimate of the prevalence of B12 deficiency in individuals over the age of 65 being admitted to long-term care. The good news: screening by a simple blood test on an annual basis will help to eradicate this deficiency

"The negative effects of a B12 deficiency for an at-risk community such as elderly adults in long-term care should be a vital concern for policy makers, staff and leadership at long-term care homes, as well as provincial and federal health departments, and warrants consideration of mandatory B12 screening at admission" states Professor Heather Keller, Schlegel Research Chair Nutrition & Aging, University of Waterloo. "This is of particular importance in the context of our aging population with more Canadians requiring long-term care.

A B12 deficiency is a relatively common but highly preventable deficiency in older adults. To date, there is a minimal understanding of the prevalence of this vitamin deficiency among individuals admitted to long-term care facilities. This study addresses this knowledge gap and makes recommendations for further research including more data on the incidence of B12 deficiencies over the first year of residency at long-term care facilities, and the need for additional studies to understand the benefits and costs of screening versus treatment of all residents.

The paper, "Vitamin B12 status in older adults living in Ontario long-term care homes: prevalence and incidence of deficiency with supplementation as a protective factor" by Kaylen Pfisterer (first author), Mike Sharratt, George Heckman and Heather Keller was published today in Applied Physiology, Nutrition, and Metabolism.

B vitamins more effective in preventing cognitive decline in people with higher omega 3 levels

While research has already established that B vitamin supplements can help slow mental decline in older people with memory problems, an international team have now found that having higher levels of Omega-3 fatty acids in your body could boost the B vitamins' effect.

The team, from the Universities of Cape Town, Oslo, Oxford and the UAE, studied more than 250 people with mild cognitive impairment (MCI) in Oxford. MCI is when brain function is below what is normally expected for a person's age but is not significant enough to interfere with daily life. While it is not as serious as dementia, if untreated it often progresses to become dementia.

Dr Celeste de Jager said: 'We previously found that B vitamins are able to slow or prevent the atrophy of the brain and memory decline in people with MCI. This was most effective in those who had above average blood levels of homocysteine, a factor related to B vitamin status that may be toxic to the brain. Scientists in our team initially found that there was a link between Omega-3 levels, homocysteine, and brain atrophy rates. We wanted to find out whether Omega-3 and B vitamins might interact to prevent cognitive decline.'

At the start of the study, each person was given a set of tests to measure their cognition, and had a blood test to determine the levels of two Omega-3 fatty acids commonly found in oily fish: docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA).

The participants were split into two randomly-selected groups, who received either a B-vitamin supplement or a placebo pill over two years. Their cognitive performance was also measured and the results compared with the baseline results from the start of the study.

Dr Abderrahim Oulhaj said: 'We found that for people with low levels of Omega-3, the vitamin supplements had little to no effect. But for those with high baseline Omega-3 levels, the B vitamins were very effective in preventing cognitive decline compared to the placebo. This result complements our previous finding that B vitamins slow the rate of brain atrophy in MCI only in those with a good Omega-3 level to start with.'

The team also found that levels of DHA might be more important than levels of EPA, although they caution that more research must be done to establish whether this is true.

Professor David Smith said: 'The next stage will be to see whether providing a combination of B vitamins and Omega-3 supplements can slow the conversion from MCI to Alzheimer's disease. This would be an important step in the prevention of Alzheimer's disease. We have high hopes that this trial would work but funding is not easy to obtain for such studies.'

Dr Doug Brown, Director of Research and Development at Alzheimer's Society said: 'These results help us to tease apart who could benefit from taking B vitamins, suggesting that they might only improve cognition in people who have high levels of Omega-3 oils in their blood. Encouragingly, these findings suggest that for some older people a combination of fish oil supplements and B vitamins may help to improve thinking and memory.

'As this study shows, the relationship between nutrition and brain health is complex and we need to see increased research efforts to help us understand the role that diet and nutrition can play in reducing a person's risk of dementia.'

The paper, Omega-3 fatty acid status enhances the prevention of cognitive decline by B vitamins in Mild Cognitive Impairment, is published in the Journal of Alzheimer's Disease (doi:10.3233/JAD-150777).

Continuing debate regarding the validity of the evidence used to create the 2015 Dietary Guidelines

What did you eat yesterday and should we believe you?" The answer to that question, and others like it, are part of a continuing controversy about U.S. government-issued dietary recommendations presented in The Dietary Guidelines for Americans 2015-2020, which was released on January 7. Two Letters to the Editor of Mayo Clinic Proceedings follow up on a recent study and the accompanying editorial about data from the National Health and Nutrition Examination Survey (NHANES), a widely-cited source within the nutrition community.

These letters continue the debate about the validity of memory-based dietary assessment methods (M-BMs) in formulating dietary policies and recommendations for the general public. In the original article, an obesity theorist and cardiovascular health researchers claimed that the main source of dietary information used by the U.S. government's 2015 Dietary Guidelines Advisory Committee (DGAC) is scientifically inadmissible because it is based on M-BMs and people do not accurately report what they eat. In an editorial response to that article, health researchers suggested that the purported flaws are well-appreciated by nutritional researchers and can be mitigated by using multiple data sources, resulting in valid data.

While not specifically addressing the use of M-BMs, the U.S. House Committee on Agriculture met on October 7, 2015, to discuss the 2015 Dietary Guidelines for Americans. Both Tom Vilsack, Secretary of the Department of Agriculture (USDA), and Sylvia Burwell, Secretary of the Department of Health and Human Services (DHHS), testified about the DGAC, the Guidelines, and the more than 29,000 public comments that were submitted. A significant number of questions from the committee concerned the credibility of recommendations that have changed over time.

Lead author Edward Archer, PhD, of the Office of Energetics, Nutrition Obesity Research Center, University of Alabama at Birmingham, Birmingham, AL, and co-authors Gregory Pavela, PhD, and Carl J. Lavie, MD, from the Department of Cardiovascular Diseases, John Ochsner Heart and Vascular Institute, Ochsner Clinical School - the University of Queensland School of Medicine, New Orleans, LA, have now commented on their original article and the editorial response. They continue to maintain that M-BMs are scientifically invalid and further that defenders of their use have ignored repeated empirical refutation and have not presented valid counter-arguments.

Archer, Pavela, and Lavie reiterate that M-BMs are "are pseudoscientific and inadmissible in scientific research and the formulation of national dietary guidelines." They continue, "it is time for the U.S. Department of Agriculture, Centers for Disease Control and Prevention, and the National Institutes of Health to recognize and acknowledge the empirical refutation of M-BMs and reexamine the extensive utilization and funding of these data collection protocols."

In a response from the authors of the original editorial, Brenda M. Davy, PhD, RD, and Paul A. Estabrooks, PhD, both from the Department of Human Nutrition, Foods, and Exercise, Virginia Tech, Blacksburg, VA, review what they consider misrepresentations and inaccuracies in the Archer et al letter. They cite references to other studies that have discussed M-BMs and their recognized limitations. "DGAC does in fact highlight the need for randomized controlled trials in many subject areas to strengthen the evidence base, as well as the need for dietary biomarker research, to better inform future dietary guidelines," explain Davy and Estabrooks.

Davy and Estabrooks also suggest another factor that may be fueling some of the controversy. Specifically, they note that there have been significant efforts by the food industry to fight proposed dietary guidelines.

According to William L. Lanier, MD, Editor-in-Chief of the Proceedings, "The collective comments of these authors reflect widely held concerns among experts as well as lay people regarding the scientific foundations of governmental dietary guidelines, the interpretation of the available data, and the magnitude and direction of recent guideline changes. There may be a multiplicity of interpretations, filtered through the expertise, experiences, and goals of the interpreter. As such, it appears that thoughtful disagreements -- as seen in the exchanges between Archer et al and Davy and Estabrooks -- will continue, especially in light of the scientific, economic, and political perspectives of the multiple constituencies involved."

Mentally challenging activities key to a healthy aging mind

One of the greatest challenges associated with the growing numbers of aged adults is how to maintain a healthy aging mind. Taking up a new mental challenge such as digital photography or quilting may help maintain cognitive vitality, say researchers reporting in Restorative Neurology and Neuroscience.

Recent evidence suggests that engaging in enjoyable and enriching lifestyle activities may be associated with maintaining cognitive vitality. However, the underlying mechanism accounting for cognitive enhancement effects have been poorly understood.

Investigators at the University of Texas at Dallas proposed that only tasks that involved sustained mental effort and challenge would facilitate cognitive function. Senior author Denise Park and lead author Ian McDonough compared changes in brain activity in 39 older adults that resulted from the performance of high-challenge activities that required new learning and sustained mental effort compared to low-challenge activities that did not require active learning. All of the participants underwent a battery of cognitive tests and brain scans using functional magnetic resonance imaging (fMRI), an MRI technology that measures brain activity by detecting changes associated with blood flow.

Participants were randomly assigned to the high-challenge, low-challenge, or placebo groups. The high-challenge group spent at least 15 hours per week for 14 weeks learning progressively more difficult skills in digital photography, quilting, or a combination of both. The low-challenge group met for 15 hours per week to socialize and engage in activities related to subjects such as travel and cooking with no active learning component. The placebo group engaged in low-demand cognitive tasks such as listening to music, playing simple games, or watching classic movies. All participants were tested before and after the 14-week period and a subset was retested a year later.

The high-challenge group demonstrated better memory performance after the intervention, and an increased ability to modulate brain activity more efficiently to challenging judgments of word meaning in the medial frontal, lateral temporal, and parietal cortex regions of the brain. These are brain areas associated with attention and semantic processing. Some of this enhanced brain activity was maintained a year later. This increased neural efficiency in judging words was demonstrated by participants showing lowered brain activity when word judgments were easy and increasing activity when they became hard. This is a pattern of response typical of young adults. Before participating in the high-challenge intervention, the older adults were processing every item, both easy and hard, with maximum brain activity. After participation, they were able to modulate their brain activity to the demands of the task, thus showing a more efficient use of neural resources. This change in modulation was not observed in the low-challenge group.

The findings show that mentally demanding activities may be neuroprotective and an important element for maintaining a healthy brain into late adulthood.

"The present findings provide some of the first experimental evidence that mentally-challenging leisure activities can actually change brain function and that it is possible that such interventions can restore levels of brain activity to a more youth-like state. However, we would like to conduct much larger studies to determine the universality of this effect and understand who will benefit the most from such an intervention," explained senior author Denise C. Park, PhD, of the Center for Vital Longevity, School of Behavioral and Brain Sciences, University of Texas at Dallas.

Ian McDonough, who is now an assistant professor of Psychology at the University of Alabama and was first author on the study, said: "The study clearly illustrates that the enhanced neural efficiency was a direct consequence of participation in a demanding learning environment. The findings superficially confirm the familiar adage regarding cognitive aging of 'Use it or lose it.'"

Denise Park added, "Although there is much more to be learned, we are cautiously optimistic that age-related cognitive declines can be slowed or even partially restored if individuals are exposed to sustained, mentally challenging experiences."

Women who eat more potatoes before pregnancy may have higher rates of gestational diabetes

Women who eat more potatoes before pregnancy may have higher rates of gestational diabetes--the form that occurs during pregnancy--compared to women who consume fewer potatoes, suggests a National Institutes of Health (NIH) study. The researchers propose that substituting potatoes with other vegetables, legumes or whole grains may help lower gestational diabetes risk. The findings appear in The BMJ (formerly the British Medical Journal).

Gestational diabetes is a common pregnancy complication that causes high blood sugar levels in the mother. The disorder can lead to future health problems for mother and child. Previous studies have linked foods with a high glycemic index, a measure of the ability to raise blood sugar levels, to a higher risk of gestational or type 2 diabetes. However, until the current study, the effect of potatoes, a common, high-glycemic food, on the development of gestational diabetes was unknown.

Researchers from NIH's Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) and Harvard University evaluated more than 15,000 women in the Nurses' Health Study II. They analyzed records from 1991 to 2001 of women who had no history of illness before pregnancy and had not had gestational diabetes before. Every four years, the women filled out a questionnaire on the kinds of foods they had eaten during the previous year. For potatoes, the women were asked if they had consumed baked, boiled, or mashed potatoes, fries or potato chips, with possible responses ranging from "never" to "six or more times a day."

The researchers found that women who ate more potatoes had a higher risk of gestational diabetes. They estimated reductions in gestational diabetes risk by substituting the following foods for two servings of potatoes per week:

• 9 percent for other vegetables
• 10 percent for legumes
• 12 percent for whole grain foods

The authors cautioned, however, that because their study was not designed to prove cause and effect, their results do not prove conclusively that potato consumption directly leads to gestational diabetes. They added that their results need to be confirmed by other studies.

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Blueberries, citrus fruits and red wine associated with reduced erectile dysfunction

Flavonoid-rich foods are associated with a reduced risk of erectile dysfunction - according to a new collaborative study from the University of East Anglia (UEA) and Harvard University.

Research published today in The American Journal of Clinical Nutrition reveals that eating foods rich in certain flavonoids is associated with a reduced risk of erectile dysfunction in men, with the greatest benefit in those under 70.

Of all the different flavonoids, Anthocyanins (found in blueberries, cherries, blackberries, radishes and blackcurrant), flavanones and flavones (found in citrus fruits) were found to offer the greatest benefits in preventing the condition.

It is already known that increased exercise can improve erectile function, but this research shows that eating a flavonoid-rich diet is as good for erectile function as briskly walking for up to five hours a week.

The study also showed that a higher total fruit intake was associated with a 14 per cent reduction in the risk of erectile dysfunction. And that a combination of consuming flavonoid-rich foods with exercise can reduce the risk by 21 per cent.

The study was carried out by nutrition departments at the Harvard TH Chan School of Public Health and UEA's Norwich Medical School.

Lead researcher Prof Aedin Cassidy from UEA said: "We already knew that intake of certain foods high in flavonoids may reduce the risk of conditions including diabetes and cardiovascular disease. This is the first study to look at the association between flavonoids and erectile dysfunction, which affects up to half of all middle-aged and older men.

"Flavonoids are present in many plant-based foods and drinks including fruits, vegetables, tea, herbs and wine. We examined six main types of commonly consumed flavonoids and found that three in particular - anthocyanins, flavanones and flavones - are beneficial.

"Men who regularly consumed foods high in these flavonoids were 10 per cent less likely to suffer erectile dysfunction. In terms of quantities, we're talking just a few portions a week."

More than 50,000 middle aged men were included in this large population based study. They were asked about their ability to have and maintain an erection sufficient for intercourse - dating back to 1986. Data on dietary intake was also collected every four years.

The research team took into account a range of factors such as body weight, physical activity, amount of caffeine consumed, and whether the participants smoked. The research was also restricted to men who were otherwise in good health.

More than one third of the men surveyed reported suffering new onset erectile dysfunction. But those who consumed a diet rich in anthocyanins, flavones and flavanones were less likely to suffer the condition.

Prof Cassidy said: "The top sources of anthocyanins, flavones and flavanones consumed in the US are strawberries, blueberries, red wine, apples, pears, and citrus products."

"We also found that the benefits were strongest among younger men," she added.

The team also looked at other lifestyle factors and found that men who consumed a high intake of anthocyanins and flavanones and who were also physically active had the lowest risk of erectile dysfunction.

Dr Eric Rimm, senior author on the study and a Professor of Epidemiology and Nutrition at the Harvard TH Chan School of Public Health, said: "As well as improving sexual health for middle-aged men, there is another important benefit linked to heart health. Erectile dysfunction is often an early barometer of poor vascular function and offers a critical opportunity to intervene and prevent cardiovascular disease, heart attack and even death.

"Men with erectile dysfunction are likely to be highly motivated to make healthier lifestyle choices, such as exercising more and eating the right foods - which would greatly benefit their long-term cardiovascular health as well."

Sugar consumption plays greater role in heart disease than saturated fat

Atherosclerotic Coronary Heart Disease (CHD) is responsible for one in every six deaths in the United States as well as being the leading cause of death throughout the developed world. Healthcare professionals have for many years sought to limit and control CHD by focusing on prevention and, from a dietary perspective, on limiting saturated fats.

In an article published in the journal Progress in Cardiovascular Diseases, Saint Luke's Mid America Heart Institute cardiovascular research scientist and James J. DiNicolantonio, PharmD, and James H. O'Keefe, MD, examined the question of whether that focus may be misplaced and ask does sugar have a greater impact on coronary heart disease than saturated fat?

The theory of dietary saturated fats as the principal promoter of elevated serum cholesterol and heart disease stems from research beginning in the 1950's by an American scientist Ancel Keys. It was this theory which was embraced by the American Heart Association and the US federal government in the 1960s and 70s. However, at the same time of Keys research, a British physiologist John Yudkin argued that sugar intake was more closely related to incidence of and mortality from CHD.

Both Yudkin and Keys were able to support their theories through observational studies in large part because people eat foods, not isolated food constituents. Dietary sources of saturated fat are also often dietary sources of sugar and people who eat lots of sugar often also eat lots of saturated fat.

Along with co-author, Sean C. Lucan, MD, MPH, MS, from the Albert Einstein College of Medicine, DiNicolantonio and O'Keefe evaluated the evidence to date linking saturated fats and sugars to CHD, considering basic science, epidemiology, and clinical trial data related to CHD risk, CHD events, and CHD mortality. The authors concluded that sugar consumption, particularly in the form of refined added sugars, are a greater contributor to CHD than saturated fats.

"While the original studies upon which the longstanding guidelines were based were largely observational," said DiNicolantonio, "We now have more than a half century of data as well as increased understanding of how nutrition impacts the body and specifically coronary heart disease."

The metabolic aspects of saturated fatty acids (SFAs) are complex but existing research suggests that certain SFAs may actually confer measurable benefits for lipid profiles and CHD risk. For instance, some SFAs increase high-density lipoprotein cholesterol (HDL), which is often referred to as the "good cholesterol" as this lipoprotein is associated with a reduced risk of CHD

Replacing saturated fats, or any other component, from one's diet almost inevitably means replacing it with something else. When carbohydrates, particularly refined carbohydrates like sugar, replace saturated fats, which can have a negative impact on lipid profiles (HDL tends to fall and triglycerides tend to rise).

As stated earlier, people don't eat isolated fatty acids - they eat foods that are a mix of various fatty acids and other food constituents. While high intakes from processed meats may increase risk of CHD, higher intakes from dairy sources of saturated fat may not only pose no risk but actually decrease risk.

Consuming a diet high in sugar for just a few weeks has been shown to cause numerous abnormalities found in patients with CHD, such as high total cholesterol, triglycerides, LDL, oxidized LDL, uric acid, insulin resistance and abnormal glucose tolerance, low HDL, and altered platelet function. The overall effect of consuming a diet high in sugar on these numerous health markers is likely more detrimental to overall health compared to increased consumption of saturated fat, which can increase LDL but at the same time raise HDL.

Added fructose - generally in the form of sucrose (table sugar) or high fructose corn syrup (HFCS) in processed foods and beverages seems especially potent for producing harm. Consuming these sugars can lead to resistance in leptin, which is a key hormone in the maintenance of normal body weight. The overconsumption of added fructose undoubtedly increases the risk for obesity, which is also a risk factor for CHD.

Excess fructose also markedly increases the risk for non-alcoholic fatty liver disease (NAFLD) - the most common liver disease in the US and a strong independent risk factor for CHD. The association between NAFLD and CHD is stronger than the link between CHD and smoking, hypertension, diabetes, male gender, high cholesterol or metabolic syndrome.

Sugars occurring naturally in fruits and vegetables pose no increased risk for CHD. The problem is refined sugars - with ultraprocessed foods being of greatest concern. Products with added sugars represent 75% of all packaged foods and beverages in the US and most commonly contain sucrose or HFCS, which seem to raise CHD risk even more than other sugars such as glucose.

A diet high in sugar has also been found to promote prediabetes and diabetes. And patients with both of these conditions have a much greater risk for CHD compared to normal healthy patients, particularly a severe narrowing of the left main coronary artery.

Ultra-processed foods also tend to be sources of saturated fats but the harms associated with eating these products may have nothing to do with the fat and everything to do with processed foods themselves. Therefore, best advice is to avoid processed foods rather than to simply avoid SFAs as avoiding SFAs might direct people away from foods that are not only completely benign but actually beneficial (such as dairy foods) but also steer people towards foods that may be harmful - i.e. low-fat, ultra-processed, with huge amounts of hidden added sugars.

"After a thorough analysis of the evidence it seems appropriate to recommend dietary guidelines shift focus away from recommendations to reduce saturated fat and towards recommendations to avoid added sugars," said Dr DiNicolantonio. "Most importantly recommendations should support the eating of whole foods whenever possible and the avoidance of ultra-processed food."

Low blood levels of bicarbonate linked to earlier death in healthy older adults

Low blood levels of bicarbonate may indicate an elevated risk of premature death in generally healthy older individuals, according to a study appearing in an upcoming issue of the Clinical Journal of the American Society of Nephrology (CJASN). The findings suggest that the blood marker is an important health indicator and that future studies should examine the potential of increasing bicarbonate levels to prolong life.

To keep the body's pH in a healthy range so that cells and organs can work properly, the kidneys and lungs work together by varying the levels of bicarbonate (a base) and carbon dioxide (an acid) in the blood. Critically ill patients with severe acid-base abnormalities have a very low likelihood of surviving their illness, but it's unclear whether more subtle changes in the body's acid-base status have an effect on the longevity of relatively healthy older people.

To investigate, Kalani Raphael, MD (University of Utah) and his colleagues looked at how measurements of pH, carbon dioxide, and bicarbonate link with long-term survival in relatively healthy older individuals. Their analysis focused on information concerning 2287 participants in the Health, Aging, and Body Composition Study, a prospective study of well-functioning black and white adults aged 70 to 79 years that began in 1997. Survival data were collected through February 2014, and participants were followed for an average of 10.3 years.

People with normal or high bicarbonate levels had a similar risk of dying during follow-up, but participants with low bicarbonate had a 24% higher risk compared with these groups.

"What we found was that generally healthy older people with low levels of bicarbonate had a higher risk of death," said Dr. Raphael. "Adding the pH measurement into the equation didn't change the results, which is important because pH is not routinely measured.

The findings suggest that blood bicarbonate concentrations, which are commonly measured, may help clinicians identify people at elevated risk of premature death. In people with low bicarbonate levels, some may benefit from increasing intake of foods that produce bicarbonate in the body, such as fruits and vegetables.

Higher dietary nitrate and green leafy vegetable intake associated with lower risk of glaucoma

Greater intake of dietary nitrate and green leafy vegetables was associated with a 20 percent to 30 percent lower risk of primary open-angle glaucoma, according to a study published online by JAMA Ophthalmology.

Elevated intraocular pressure and impaired autoregulation of optic nerve blood flow are implicated in primary open-angle glaucoma (POAG; optic nerve damage from multiple possible causes that is chronic and progresses over time). Evidence suggests that nitrate or nitrite, precursors for nitric oxide, is beneficial for blood circulation. Jae H. Kang, Sc.D., of Brigham & Women's Hospital and Harvard Medical School, Boston, and colleagues evaluated the association between dietary nitrate intake, derived mainly from green leafy vegetables, and POAG. The researchers followed up participants biennially in the prospective cohorts of the Nurses' Health Study (63,893 women; 1984-2012) and the Health Professionals Follow-up Study (41,094 men; 1986-2012). Eligible participants were 40 years or older, were free of POAG, and reported eye examinations. Information on diet was updated with questionnaires.

During follow-up, 1,483 incident cases of POAG were identified. Participants were divided into quintiles (one of five groups) of dietary nitrate intake (quintile 5, approximately 240 mg/d; quintile 1, approximately 80 mg/d). The researchers found that greater intake of dietary nitrate and green leafy vegetables was associated with a 20 percent to 30 percent lower POAG risk; the association was particularly strong (40 percent-50 percent lower risk) for POAG with early paracentral visual field loss (a subtype of POAG linked to dysfunction in blood flow autoregulation).

"These results, if confirmed in observational and intervention studies, could have important public health implications," the authors write.