Friday, July 29, 2016

Frequent nut consumption associated with less inflammation

In a study of more than 5,000 people, investigators from Brigham and Women's Hospital have found that greater intake of nuts was associated with lower levels of biomarkers of inflammation, a finding that may help explain the health benefits of nuts. The results of the study appear July 27 in the American Journal of Clinical Nutrition.

"Population studies have consistently supported a protective role of nuts against cardiometabolic disorders such as cardiovascular disease and type 2 diabetes, and we know that inflammation is a key process in the development of these diseases," said corresponding author Ying Bao, MD, ScD, an epidemiologist in BWH's Channing Division of Network Medicine. "Our new work suggests that nuts may exert their beneficial effects in part by reducing systemic inflammation."

Previously Bao and her colleagues observed an association between increased nut consumption and reduced risk of major chronic diseases and even death, but few prospective cohort studies had examined the link between nut intake and inflammation. In the current study, the research team performed a cross-sectional analysis of data from the Nurses' Health Study, which includes more than 120,000 female registered nurses, and from the Health Professionals Follow-Up Study, which includes more than 50,000 male health professionals. The team assessed diet using questionnaires and looked at the levels of certain telltale proteins known as biomarkers in blood samples collected from the study participants. They measured three well-established biomarkers of inflammation: C-reactive protein (CRP), interleukin 6 (IL6) and tumor necrosis factor receptor 2 (TNFR2).

After adjusting for age, medical history, lifestyle and other variables, they found that participants who had consumed five or more servings of nuts per week had lower levels of CRP and IL6 than those who never or almost never ate nuts. In addition, people who substituted three servings per week of nuts in place of red meat, processed meat, eggs or refined grains had significantly lower levels of CRP and IL6.

Peanuts and tree nuts contain a number of healthful components including magnesium, fiber, L-arginine, antioxidants and unsaturated fatty acids such as α-linolenic acid. Researchers have not yet determined which of these components, or if the combination of all of them, may offer protection against inflammation, but Bao and her colleagues are interested in exploring this further through clinical trials that would regulate and monitor diet.

"Much remains unknown about how our diet influences inflammation and, in turn, our risk of disease," said Bao. "But our study supports an overall healthful role for nuts in the diet and suggests reducing inflammation as a potential mechanism that may help explain the benefits of nuts on cardiometabolic diseases."

Wednesday, July 27, 2016

Resveratrol slows the cognitive decline of Alzheimer's patients

Resveratrol, given to Alzheimer's patients, appears to restore the integrity of the blood-brain barrier, reducing the ability of harmful immune molecules secreted by immune cells to infiltrate from the body into brain tissues, say researchers at Georgetown University Medical Center. The reduction in neuronal inflammation slowed the cognitive decline of patients, compared to a matching group of placebo-treated patients with the disorder.

The laboratory data provide a more complete picture of results from a clinical trial studying resveratrol in Alzheimer's disease that was first reported in 2015. The new findings will be presented at the Alzheimer's Association International Conference 2016 in Toronto on July 27th.

The Alzheimer's disease brain is damaged by inflammation, thought to be due to a reaction to the buildup of abnormal proteins, including Abeta40 and Abeta42, linked to destruction of neurons. Researchers believe that heightened inflammation -- which was historically thought to come only from "resident" brain immune cells -- worsens the disease. According to the researchers, this study suggests that some of the immune molecules that can cause inflammation in the blood can enter the brain through a leaky blood-brain barrier.

"These findings suggest that resveratrol imposes a kind of crowd control at the border of the brain. The agent seems to shut out unwanted immune molecules that can exacerbate brain inflammation and kill neurons," says neurologist Charbel Moussa, MD, PhD, scientific and clinical research director of the GUMC Translational Neurotherapeutics Program. "These are very exciting findings because it shows that resveratrol engages the brain in a measurable way, and that the immune response to Alzheimer's disease comes, in part, from outside the brain."

Resveratrol is a naturally occurring compound found in foods such as red grapes, red wine, raspberries and dark chocolate. GUMC researchers, led by R. Scott Turner, MD, PhD, tested the substance in 119 patients, the largest nationwide phase II clinical trial to study high-dose pure synthetic (pharmaceutical-grade) resveratrol in individuals with mild to moderate Alzheimer's. The study was published Sept. 11, 2015 in Neurology.

The new part of the resveratrol study examines specific molecules in the cerebrospinal fluid (CSF) taken from participants with biomarker-confirmed Alzheimer's disease -- 19 were given a placebo, and 19 treated daily for a year with resveratrol, equivalent to the amount found in about 1,000 bottles of red wine.

Previous studies with animals found that age-related diseases--including Alzheimer's -- can be prevented or delayed by long-term caloric restriction (consuming two-thirds the normal caloric intake). The researchers studied resveratrol because it mimics the effects of caloric restriction by also activating proteins called sirtuins.

In this new study, Moussa and Turner found that treated patients had a 50 percent reduction in matrix metalloproteinase-9 (MMP-9) levels in the cerebrospinal fluid. MMP-9 is decreased when sirtuin1 (SIRT1) is activated. High levels of MMP-9 cause a breakdown in the blood-brain barrier, allowing proteins and molecules from the body to enter the brain. Normally low MMP-9 levels maintain the barrier, say the researchers.

"These new findings are exciting because they increase our understanding of how resveratrol may be clinically beneficial to individuals with Alzheimer's disease. In particular, they point to the important role of inflammation in the disease, and the potent anti-inflammatory effects of resveratrol," says Turner, director of GUMC's Memory Disorders Program and co-director of the Translational Neurotherapeutics Program.

They also found that resveratrol increased the level of molecules linked to a long-term beneficial or "adaptive" immune reaction, suggesting involvement of inflammatory cells that are resident in the brain, says Moussa. "This is the kind of immune response you want -- it is there to remove and degrade neurotoxic proteins."

"A puzzling finding from the resveratrol study (as well as immunotherapy strategies for Alzheimer's under investigation) is the greater shrinkage of the brain found with treatment. These new findings support the notion that resveratrol decreases swelling that results from inflammation in Alzheimer's brain," says Turner. "This seemingly paradoxical effect is also found with many of the drugs that are beneficial for patients with multiple sclerosis -- another brain disease characterized by excessive inflammation."

Moussa says that resveratrol should be further tested in a phase III study, but the agent, by itself, is unlikely to be a complete treatment for Alzheimer's. It does not inhibit destruction of brain neurons by tau, another protein aggregate involved in the disease, so a likely beneficial treatment would combine resveratrol with an agent that targets tau, he says.

Women who start menstruation and menopause later more likely to live to 90

The number of women living to age 90 in the United States has increased significantly in the past century. Currently estimated at 1.3 million, this demographic is expected to quadruple by 2050. A new study by researchers at University of California San Diego School of Medicine found that women who start menstruation and experience menopause later in life may have increased chances of surviving nine decades.

The study, published online July 27, 2016 in Menopause, is the first to evaluate the association of reproductive factors with survival to a specific advanced age, such as 90 years old.

"Achieving longevity is an overarching public health goal with so many of us asking 'how do I live longer?' Our study found that women who started menstruation at age 12 or older, experienced menopause, either naturally or surgically, at age 50 or older and had more than 40 reproductive years had increased odds of living to 90-years-old," said Aladdin Shadyab, PhD, with the Department of Family Medicine and Public Health at UC San Diego School of Medicine.

Of the approximately 16,000 participants in the racially and ethnically diverse group, 55 percent survived to age 90. The participants were from the Women's Health Initiative (WHI), a national longitudinal investigation of postmenopausal women, and were followed for 21 years.

"Our team found that women who started menstruation at a later age were less likely to have certain health issues, like coronary heart disease, and those who experienced menopause later in life were more likely to be in excellent health overall, which may be a possible explanation for our findings," said Shadyab.

Women who started menstruation and experienced menopause at a later age were also less likely to be smokers or have a history of diabetes.

"Factors, such as smoking, can damage the cardiovascular system and ovaries, which can result in earlier menopause. Women with later menopause and a longer reproductive lifespan may have decreased risk of cardiovascular diseases," said Shadyab.

Shadyab, whose grandfather lived to age 102-years-old and sparked his passion for studying aging, said more studies are needed to examine how lifestyle, genetics and environmental factors may explain the link between reproductive lifespan and longevity.

"This study is just the beginning of looking at factors that can predict a woman's likelihood of surviving to advanced age," said Shadyab. "Using my grandfather as inspiration, I am excited to take these results and continue to contribute to the science behind longevity."

Vitamin D levels predict risk of brain decline in Chinese elderly

Research conducted by Duke-NUS Medical School (Duke-NUS) and Duke University has associated low vitamin D levels with increased subsequent risk of cognitive decline and impairment in the Chinese elderly.

Produced primarily in the skin upon exposure to sunlight, Vitamin D is necessary for maintaining healthy bones and muscles. It is now believed to also play a significant role in maintaining healthy brain function. An increased risk of cardiovascular and neurodegenerative diseases has been observed in those with low vitamin D levels, and studies from Europe and North America have linked low vitamin D levels with future cognitive decline.

This study asks similar questions of vitamin D levels and cognition in the Chinese elderly. It is the first large-scale prospective study in Asia to study the association between vitamin D status and risk of cognitive decline and impairment in the Chinese elderly. 1,202 study subjects greater than or equal to 60 years of age from the Chinese Longitudinal Health Longevity Survey took part in this study. Their baseline vitamin D levels were measured at the start of the study, and their cognitive abilities were assessed over 2 years.

Regardless of gender and extent of advanced age, individuals with lower vitamin D levels at the start of the study were approximately twice as likely to exhibit significant cognitive decline over time. In addition, low vitamin D levels at baseline also increased the risk of future cognitive impairment by 2-3 times.

"Although this study was conducted on subjects from China, the results are applicable to regions in Asia where a large proportion of the elderly are ethnically Chinese, like Singapore," said Professor David Matchar, first author of the study and Director of the Health Services and Systems Research Programme at Duke-NUS Medical School.

These findings reinforce the notion that vitamin D protects against neuron damage and loss, and call for more intensive investigations into the effects of vitamin D supplements on cognitive decline. Better understanding of the mechanism by which vitamin D protects neurons may help identify effective interventions to stem the rapidly increasing prevalence of cognitive decline observed in aging populations.

Tuesday, July 26, 2016

Evidence insufficient to make recommendation regarding visual skin examination by a clinician

The U.S. Preventive Services Task Force (USPSTF) has concluded that the current evidence is insufficient to assess the balance of benefits and harms of visual skin examination by a clinician to screen for skin cancer in asymptomatic adults. The report appears in the July 26 issue of JAMA.

This is an I statement, indicating that that the current evidence is insufficient to assess the balance of benefits and harms of the service. Evidence is lacking, of poor quality, or conflicting, and the balance of benefits and harms cannot be determined.

Basal and squamous cell carcinoma are the most common types of cancer in the United States and represent the vast majority of all cases of skin cancer; however, they rarely result in death or substantial morbidity, whereas melanoma skin cancer has notably higher mortality rates. In 2016, an estimated 76,400 U.S. men and women will develop melanoma and 10,100 will die from the disease. To update its 2009 recommendation, the USPSTF reviewed the evidence on the effectiveness of screening for skin cancer with a clinical visual skin examination in reducing skin cancer morbidity and mortality and death from any cause; its potential harms, including any harms resulting from associated diagnostic follow-up; its test characteristics when performed by a primary care clinician vs a dermatologist; and whether its use leads to earlier detection of skin cancer compared with usual care.

The USPSTF is an independent, volunteer panel of experts that makes recommendations about the effectiveness of specific preventive care services such as screenings, counseling services, and preventive medications.


Evidence is adequate that visual skin examination by a clinician has modest sensitivity and specificity for detecting melanoma. Evidence is more limited and inconsistent regarding the accuracy of the clinical visual skin examination for detecting nonmelanoma skin cancer.

Benefits of Early Detection and Treatment

Evidence is inadequate to reliably conclude that early detection of skin cancer through visual skin examination by a clinician reduces morbidity or mortality.

Harms of Early Detection and Treatment

Evidence is adequate that visual skin examination by a clinician to screen for skin cancer leads to harms that are at least small, but current data are insufficient to precisely bound the upper magnitude of these harms. Potential harms of skin cancer screening include misdiagnosis, overdiagnosis, and the resulting cosmetic and--more rarely-- functional adverse effects resulting from biopsy and overtreatment.


Evidence to assess the net benefit of screening for skin cancer with a clinical visual skin examination is limited. Direct evidence on the effectiveness of screening in reducing melanoma morbidity and mortality is limited to a single fair-quality ecologic study with important methodological limitations. Information on harms is similarly sparse. The potential for harm clearly exists, including a high rate of unnecessary biopsies, possibly resulting in cosmetic or, more rarely, functional adverse effects, and the risk of overdiagnosis and overtreatment.

Wednesday, July 20, 2016

Milk works best to extinguish the heat from chile peppers

The next time you bite off more than you can handle in regard to a hot chile pepper, your best bet is to drink some milk. That's according to research conducted by New Mexico State University's Chile Pepper Institute.

"Capsaicin is the chemical compound found in chile peppers that makes them taste hot," said Paul Bosland, an NMSU Regents Professor and director of the Chile Pepper Institute. "It turns out that milk has a protein in it that replaces the capsaicin on the receptors on your tongue. It's really the quickest way to alleviate the burning feeling."

Bosland said when capsaicin attaches to receptors in your mouth, it sends the same signal to your brain as it would if you had touched something hot. That's why some people also begin to sweat when they eat hot peppers. Milk, and other dairy products like sour cream or even ice cream, will help to put out that fire.

So, does anything else work?

"Carbohydrates also replace the capsaicin on the receptors, just not as effectively as milk," Bosland said. "These would be things like bread or sugar. Sugar is the better of the two. That's why we see the traditional Mexican desserts like flan and sopapillas with honey. These are made from breads, sugars and milk."

Bosland often gets calls asking whether alcohol will help with the heat sensation from chile peppers. The answer is no, and water won't work either. They both just wash the capsaicin around your mouth. Neither will block it.

The very first chile peppers evolved around Bolivia in South America. The early wild peppers were very small and round and were probably spread by birds because they do not have the same heat receptors in their mouths as humans do.

Experts believe that when the first humans arrived in the Western Hemisphere, probably around 15,000 years ago, they began to cultivate chile peppers and select them for various traits. The plants naturally cross-pollinate well, so new varieties are easily developed and constantly being made. Today, there are thousands of chile pepper varieties, from the super-hot Trinidad Moruga Scorpion to the standard bell pepper, which doesn't have any heat at all.

"People will often ask, which is hotter, red or green chile peppers," Bosland said. "It depends on the variety, but generally, red won't be as hot because red chile peppers will have more sugars in them, which helps to counter the heat."

An interesting situation happens when astronauts put hot sauce on their food in space, because it doesn't taste as hot as it does on earth. Bosland said researchers are still trying to figure out why that is.

Tuesday, July 19, 2016

Eating healthy fats in place of carbs or saturated fats improves risk factors for diabetes

Eating more unsaturated fats, especially polyunsaturated fats, in place of either dietary carbohydrate or saturated fats lowers blood sugar levels and improves insulin resistance and secretion, according to a new meta-analysis of data from 102 randomised controlled feeding trials in adults.

The study, led by Dariush Mozaffarian M.D., Dr.P.H., dean of the Friedman School of Nutrition Science and Policy at Tufts University, and Fumiaki Imamura, Ph.D., at the Medical Research Council (MRC) Epidemiology Unit, University of Cambridge, provides novel quantitative evidence for the effects of dietary fats and carbohydrate on the regulation of glucose and insulin levels and several other metrics linked to type 2 diabetes.

The results were published in PLOS Medicine on July 19.

Rates of insulin resistance and type 2 diabetes are rising sharply worldwide, highlighting the need for new, evidence-based preventive strategies. While a healthy diet is clearly a cornerstone of such efforts, the effects of different dietary fats and carbohydrate on metabolic health have been controversial, leading to confusion about specific dietary guidelines and priorities.

"The world faces an epidemic of insulin resistance and diabetes," said Mozaffarian, who is senior author on the study. "Our findings support preventing and treating these diseases by eating more fat-rich foods like walnuts, sunflower seeds, soybeans, flaxseed, fish, and other vegetable oils and spreads, in place of refined grains, starches, sugars, and animal fats."

"This is a positive message for the public," he added. "Don't fear healthy fats."

In their study, Imamura, Mozaffarian and colleagues performed the first systematic evaluation of all available evidence from trials to quantify the effects of different types of dietary fat (saturated, monounsaturated and polyunsaturated) and carbohydrate on key biological markers of glucose and insulin control that are linked to development of type 2 diabetes.

The team identified and summarized findings from 102 randomised controlled trials, involving a total of 4,660 adult participants, which provided meals that varied in the types and amounts of fat and carbohydrate. The team then evaluated how such variations in diet affected measures of metabolic health, including blood sugar, blood insulin, insulin resistance and sensitivity, and ability to produce insulin in response to blood sugar.

The researchers found that exchanging dietary carbohydrate or saturated fat with a diet rich in monounsaturated fat or polyunsaturated fat had a beneficial effect on key markers of blood glucose control. For example, for each five percent of dietary energy switched from carbohydrates or saturated fats to mono- or polyunsaturated fats, there is an approximately 0.1 percent reduction in HbA1c, a blood marker of long-term glucose control. The authors note that based on prior research, each 0.1 percent reduction in HbA1c is estimated to reduce the incidence of type 2 diabetes by 22 percent and cardiovascular diseases by 6.8 percent.

"Among different fats, the most consistent benefits were seen for increasing polyunsaturated fats, in place of either carbohydrates or saturated fat," said Imamura, who is first author on the study.

Given the current global pandemic of type 2 diabetes, the authors hope that these findings will help inform scientists, clinicians, and the public on dietary priorities related to dietary fats and carbohydrates and metabolic health.

"Until now, our understanding of how dietary fats and carbohydrate influence glucose, insulin, and related risk factors has been based on individual studies with inconsistent findings," Imamura said. "By combining results from more than 100 trials, we provide the strongest evidence to-date on how major nutrients alter these risks."

Virgin olive oil and hypertension

This research article by Dr. Sergio Lopez et al. is published in Current Vascular Pharmacology Journal Volume 14, Issue 6, 2016

Consumption of virgin olive oil is good for you, but why? Scientific evidence on this issue has been accumulating for a quarter century. Epidemiological, clinical, and animal studies support that the consumption of virgin olive oil, instead of other sources of dietary fats, has antihypertensive effects.

What contains does virgin olive oil contain that makes it so healthy? Virgin olive oil is an oily fruit whose composition includes large quantities of oleic acid (a monounsaturated fatty acid) and also a variety of compounds present in lower quantities, named minor constituents, such as hydrocarbons, phytosterols, triterpenic compounds, and phenolic compounds. Both oleic acid and these minor constituents confer unique bioactive properties to virgin olive oil.

How do its components protect from hypertension? They influence on factors associated with the pathophysiology of hypertension such as vascular contractibility and protect from heart and kidney cellular loss and functionality, leading to a reduction of blood pressure.

Is it a miraculous ingredient? No, it is just a food. Virgin olive oil helps in preventing and treating hypertension but its full power arises as part of the Mediterranean Diet in a global strategy for a healthy and long-lasting life.

Want to cut calories? Place orders before it's time to eat

Want to cut calories and make healthier meal choices? Try avoiding unhealthy impulse purchases by ordering meals at least an hour before eating. New findings from researchers at the Perelman School of Medicine at the University of Pennsylvania and Carnegie Mellon University show that people choose higher-calorie meals when ordering immediately before eating, and lower-calorie meals when orders are placed an hour or more in advance. The results, which have implications for addressing the nation's obesity epidemic, are published in the Journal of Marketing Research.

"Our results show that ordering meals when you're already hungry and ready to eat leads to an overall increase in the number of calories ordered, and suggest that by ordering meals in advance, the likelihood of making indulgent purchases is drastically reduced," said lead author Eric M. VanEpps, PhD, a postdoctoral researcher at the Penn Center for Health Incentives and Behavioral Economics, who conducted the studies while a graduate student at Carnegie Mellon. "The implication is that restaurants and other food providers can generate health benefits for their customers by offering the opportunity to place advance orders." Researchers conducted two field studies examining online lunch orders of 690 employees using an onsite corporate cafeteria, and a third study with 195 university students selecting among catered lunch options. Across all three studies, the researchers noted that meals with higher calorie content were ordered and consumed when there were shorter (or no) waiting periods between ordering and eating.

The first study was a secondary data analysis of over 1,000 orders that could be placed any time after 7 a.m. to be picked up between 11 a.m. and 2 p.m. The second study randomly assigned participants to place orders before 10 a.m. or after 11 a.m. The third study randomly assigned university students to order lunch before or after class, with lunches provided immediately after class.

In the first study, VanEpps and colleagues from Carnegie Mellon University found that for every hour of delay between when the order was placed and the food was ready (average delay of 105 minutes), there was a decrease of approximately 38 calories in the items ordered. In the second study, the researchers found that those who placed orders in advance, with an average delay of 168 minutes, had an average reduction of 30 calories (568 vs. 598) compared to those who ordered closer to lunchtime (with an average delay of 42 minutes between ordering and eating). The third study showed that students who placed orders in advance ordered significantly fewer calories (an average of 890 calories) compared to those who ordered at lunchtime (an average of 999 calories).

In all three studies, lower caloric totals were generally not confined to any specific population subsets. Failure to eat breakfast did not emerge as a factor in the observed effect of time delay on total lunch calories, nor were there any observed differences in meal satisfaction between meals ordered in advance and those ordered for immediate consumption.

"These findings provide one more piece of evidence that decisions made in the heat of the moment are not as far-sighted as those made in advance," said George Loewenstein, PhD, the Herbert A. Simon University Professor of Economics and Psychology at Carnegie Mellon, and senior author on the study. "For example, people who plan to practice safe sex often fail to do so when caught up in the act, and people who, in dispassionate moments, recognize the stupidity of road rage nevertheless regularly succumb to it. Unfortunately, pre-commitment strategies are more feasible when it comes to diet than to many other 'hot' behaviors."

Based on findings from other studies, VanEpps says there is a potential concern that people who cut calories in one meal might "make up" for the calorie reductions later, whether at dinner or via snacking, though there is little evidence that participants in these studies were aware that lunches ordered in advance had fewer calories. The authors suggest future research in the form of longitudinal studies that measure eating decisions over a longer period of time would be useful in addressing this issue. In addition, because the two employee workplace studies provided discounted food and the university-based study provided free food, future research examining analogous situations where participants pay full price for their meals would be beneficial.

Many skin cancer patients still too likely to sunburn

A recent study by researchers at Johns Hopkins concludes that a substantial number of people with a history of the most frequent kind of nonmelanoma skin cancers still get sunburned at the same rate as those without previous history, probably because they are not using sun-protective methods the right way or in the right amounts.

The findings, which were based on self-reporting of sunburn and sun protection practices gathered from the National Health Interview Survey, urge skin doctors and other health care providers to better educate their patients about protective skin care practices, especially for those with history of nonmelanoma skin cancer.

The findings were published in May ahead of print in the Journal of the American Academy of Dermatology.

"It is important to look at how patients are currently practicing sun protection and what they are doing that is not very effective," says Anna Chien, M.D., co-director of the Cutaneous Translational Research Program in the Department of Dermatology at the Johns Hopkins University School of Medicine. "Only then can we make strides in helping patients improve their sun protective practices by ensuring they do them the correct way." Sun exposure is the leading cause of nonmelanoma skin cancers, and treatment is estimated to cost $4.8 billion in the U.S. annually.

In the United States, Chien says, approximately 13 million white non-Hispanic individuals have a history of at least one type of nonmelanoma skin cancer, including basal cell and squamous cell cancers, putting them at a well-documented higher risk for subsequent nonmelanoma skin cancer. For example, studies show that 40 percent of those with a history of basal cell carcinoma are diagnosed with another lesion within five years.

For the new study, investigators analyzed self-reported survey results about sun protective practices from 758 people with previous nonmelanoma skin cancer and from 34,161 people without a history of skin cancer. The study focused on non-Hispanic whites, the population most affected by nonmelanoma skin cancer. Of the people without history, 18,933 were female and 15,228 were male, and of those with history, 390 were female and 368 were male.

The researchers defined protective practices as using sunscreen when going outside on a sunny day for more than an hour, wearing long sleeves or a wide-brimmed hat, and staying in the shade when outside on a sunny day for more than one hour. They defined sun avoidance as not going out into the sun.

Overall, they concluded that 44.3 percent of people with nonmelanoma skin cancer history reported frequent use of shade, compared to 27 percent of people without a history of skin cancer, and 20.5 percent of those with a history of nonmelanoma skin cancer wore long sleeves, compared to 7.7 percent of those with no history.

Additionally, 26.1 percent of those with a history of nonmelanoma skin cancer said they wore a wide-brimmed hat when outside in the sun, compared to 10.5 percent of people without a history, and 53.7 percent of those with a history of nonmelanoma skin cancer said they wore sunscreen, compared to 33.1 percent of those without a history.

Moreover, 44.7 percent of those with a history of nonmelanoma skin cancer reported using more than one form of sun protection, while only 19.4 percent of those without a history of nonmelanoma skin cancer said they did so. Multimodality, the use of multiple skin-protective practices at a time, was associated with lower odds of sunburn. It also offers a highly beneficial approach to those with previous nonmelanoma skin cancer, says Chien.

Most importantly, the researchers say, was the finding that although people with previous nonmelanoma skin cancer tend to use one or all of the protective practices, there was not a significant difference in reporting of sunburn compared to those without a history -- 29.7 percent versus 40.7 percent. This means, Chien says, that although those with a history of skin cancer are proactively using protective methods, they may not be doing so effectively, especially among younger patients. Approximately two-thirds (66.9 percent) of individuals ages 18 to 39 reported sunburn.

Chien says that while sunscreen was the most common use of sun protection reported by participants, it was not associated with lower rates of sunburn in those with previous nonmelanoma skin cancer. While noting that self-reports, such as those on which the study is based, are not entirely reliable, the disconnect among those who use sunscreen and still get burned may occur because individuals are not applying sunscreen effectively. Explaining the correct ways -- such as how much and how often -- to apply sunscreen to patients is key, says Chien.

"These results suggest that physicians need to go the extra step in educating patients on the most optimal way of utilizing sun protection methods. Public health messages should also emphasize not only sun protection but how to do it correctly," Chien says.

The researchers caution that although the data were pulled from a national survey, the results are self-reported and therefore may have some bias. In addition, Chien says, nonmelanoma skin cancer tends to be considered less important than melanoma and is thus underreported.

"The bottom line is that people should be using multiple forms of skin protective practices," says Chien. "That means incorporating shade or sun avoidance into a daily routine, or wearing a wide-brimmed hat while also applying sunscreen correctly."

Monday, July 18, 2016

Extra virgin olive oil is the best option for frying fish

Researchers at the UPV/EHU-University of the Basque Country have studied the changes that take place in fish lipids and in the oil during frying processes

The frying techniques, the nature of the oil used and the fish species have been shown to exert a great influence on the changes that take place during the process. UPV/EHU researchers have shown that the choice of cooking oil is hugely important owing to its impact on the lipid profile in the fish and on the possible generation of toxic compounds in the oil during frying, which can influence food safety and human health.

The journal Food Research International has published the article 'The influence of frying technique, cooking oil and fish species on the changes occurring in fish lipids and oil during shallow-frying, studied by H-1 NMR', which deals with the work carried out by Bárbara Nieva-Echevarría, Encarnación Goicoechea, María José Manzanos and María Dolores Guillén. To conduct this research, fillets of European seabass (Dicentrarchus labrax) and gilthead seabream (Sparus aurata) were shallow-fried in a frying plan and in a microwave oven using extra virgin olive oil and refined sunflower oil. The changes that took place in the lipid composition of the fish and of the frying oil were studied by means of Proton Nuclear Magnetic Resonance Imaging (H-1 NMR).

Migration of lipid components between the fish and the frying oil

During the shallow-frying of the fish under domestic conditions, not only do the fish lipids migrate to the frying oil, the components of the oil are also transferred to the fillet of fish. As a result, the composition of the oil used for frying is modified: firstly, it is enriched by the acyl groups ('fatty acids') that are present in a higher concentration in the fish fat than in the original oil, and secondly, and simultaneously, it is depleted in the acyl groups present in a higher concentration in the original oil than in the fish fat. So after having been used for frying, the extra virgin olive oil was richer in omega-3, omega-1 acyl groups, linoleic and saturated fats (from the fish) and poorer in oleic, which is the main acyl group in olive oil. Likewise, after having been used for frying, the sunflower oil was richer in all the acyl group types (coming from the fish) except linoleic, which is the majority acyl group in sunflower oil. Furthermore, after frying, both types of oil were enriched by small amounts of cholesterol (from the fish).

As regards the fat in the fish fillets, its composition also changed during the frying process, and became enriched by the acyl groups present in a higher concentration in the frying oil than in the fillet (in other words, oleic if extra virgin olive oil was used, or linoleic if sunflower oil was used) and in plant sterols. Simultaneously, during the frying process the lipids in the fish fillets were depleted in the acyl groups and minority components present in a greater concentration in the raw fillet than in the original oils, such as, for example, the omega-3 docosahexaenoic (DHA) and eicosapentaenoic (EPA) polyunsaturated groups.

Thermal oxidation reaction

Besides the migration of lipids during frying, because these oils are subjected to high temperatures (170 ºC) in the presence of oxygen, certain small-scale thermal oxidation may take place in them. In the extra virgin olive oil used for frying fish, this thermal oxidation reaction did not occur as it is more degradation-resistant than sunflower oil. Yet in the sunflower oil used for frying fish in the frying pan, secondary oxidation compounds (aldehydes) were formed; some of them are regarded as potentially toxic depending on the concentration in which they are found. It should be pointed out that these compounds did not form in the sunflower oil used to fry the fish in the microwave oven. Therefore, in view of the results obtained and bearing in mind the generation of these compounds that are potentially harmful for health, the healthiest option for frying is to use extra virgin olive and fry in the microwave.

Fat content of the fried fish

The fish species used was also seen to be a factor that considerably influences the fat absorption-desorption process during frying. The fat content of the gilthead seabream had diminished after frying while that of the European seabass remained similar or increased with respect to the starting level.

This study shows that the frying technique, the type of oil used and the fish species exert a great influence on the changes that take place during the frying process. Correctly selecting the oil is of paramount importance owing to its impact on the final composition of the fat in the cooked fillet and the possible generation of potentially toxic compounds in the oil during the frying process, which will greatly influence food safety and human health.

Stroke is largely preventable, with hypertension confirmed as biggest risk factor, according to global study

Hypertension (high blood pressure) remains the single most important modifiable risk factor for stroke, and the impact of hypertension and nine other risk factors together account for 90% of all strokes, according to an analysis of nearly 27000 people from every continent in the world (INTERSTROKE), published in The Lancet.

Although the same ten risk factors were important, and together accounted for 90% of stroke risk in all regions, the relative role of some individual risk factors varied by region, which the authors say should influence the development of strategies for reducing stroke risk.

Stroke is a leading cause of death and disability, particularly in low-income and middle-income countries. The two major types of stroke include ischaemic stroke (caused by blood clots), which accounts for 85% of strokes, and haemorrhagic stroke (bleeding in the brain), which accounts for 15% of strokes. Prevention of stroke is a major public health priority, but needs to be based on a clear understanding of the key preventable causes of stroke.

To estimate the proportion of strokes caused by specific risk factors, the investigators calculated the population attributable risk for each factor (PAR; an estimate of the overall disease burden that could be reduced if an individual risk factor were eliminated [4]). The PAR was 47.9% for hypertension, 35.8% for physical inactivity, 23.2% for poor diet, 18.6% for obesity, 12.4% for smoking, 9.1% for cardiac (heart) causes, 3.9% for diabetes, 5.8% for alcohol intake, 5.8% for stress, and 26.8% for lipids (the study used apolipoproteins, which was found to be a better predictor of stroke than total cholesterol). Many of these risk factors are known to also be associated with each other (e.g. obesity and diabetes), and when combined together, the total PAR for all ten risk factors was 90.7%, which was similar in all regions, age groups and in men and women.

Interestingly, the importance of some risk factors appeared to vary by region. For example, the PAR for hypertension ranged from 38.8% in western Europe, North America, and Australia to 59.6% in Southeast Asia, the PAR for alcohol intake was lowest in western Europe, North America, Australia and highest in Africa (10.4%) and south Asia (10.7%), while the PAR for physical inactivity was highest in China. Atrial fibrillation (irregular heart rhythm) was significantly associated with ischaemic stroke (PAR ranging from 3.1% in south Asia to 17.1% in western Europe, North America, and Australia), as was a high apolipoprotein [ApoB]/A1 ratio (PAR ranging from 24.8% in western Europe, North America, and Australia to 67.6% in southeast Asia).

Prof Salim Yusuf says: "INTERSTROKE demonstrates that the majority of stroke is due to common modifiable risk factors. Our findings will inform the development of global population-level interventions to reduce stroke, and how such programmes may be tailored to individual regions, as we did observe some regional differences in the importance of some risk factors by region. This includes better health education, more affordable healthy food, avoidance of tobacco and more affordable medication for hypertension and dyslipidaemia."[5]

"This is the first study that is adequately powered to explore stroke risk factors in all regions of the world and between stroke subtypes. The wider scope of this phase of our study lends a greater generalisability to the original INTERSTROKE results, and confirms the ten modifiable risk factors associated with 90% of stroke cases. The study also confirms that hypertension is the most important modifiable risk factor in all regions, and is therefore the key target in reducing the burden of stroke globally."[5]

Writing in a linked Comment, Professor Valery L Feigin and Dr Rita Krishnamurthi from the National Institute for Stroke and Applied Neurosciences, Faculty of Health and Environmental Sciences, University of Technology, Auckland, New Zealand, say: "Three key messages can be drawn from this study. First, stroke is a highly preventable disease globally, irrespective of age and sex. Second, the relative importance of modifiable risk factors and their PAR necessitates the development of regional or ethnic-specific primary prevention programmes, including priority settings such as focusing on risk factors contributing most to the risk of stroke in a particular region (as determined by PAR). Third, additional research on stroke risk factors is needed for countries and ethnic groups not included in INTERSTROKE, as well as definitive cost-effectiveness research on primary stroke prevention in key populations (eg, different age, sex, ethnicity, or region). It should also be emphasised that stroke prevention programmes must be integrated with prevention of other major non-communicable diseases that share common risk factors with stroke to be cost-effective...We have heard the calls for actions about primary prevention. Now is the time for governments, health organisations, and individuals to proactively reduce the global burden of stroke. Governments of all countries should develop and implement an emergency action plan for the primary prevention of stroke."

A high-fat Mediterranean diet may protect against breast cancer, diabetes, and cardiovascular events

According to researchers, a healthy diet can include "a lot of fat." A review of available evidence suggests that a Mediterranean diet with no restrictions on fat intake may reduce a person's risk for breast cancer diabetes, and cardiovascular events compared to other diets. The findings are published in Annals of Internal Medicine.

Despite advances in diagnosis and treatment, cardiovascular disease, diabetes, and cancer continue to be among the leading causes of morbidity and mortality in developed countries. Typical Western diets, which are high in saturated fats, sugar, and refined grains, have been linked to the development of these chronic diseases. Limited evidence has suggested that a Mediterranean diet, which is essentially plant-based, may be a healthier option.

Researchers reviewed available evidence to summarize the effect of a Mediterranean diet on health outcomes and to assess whether North American populations would be likely to adhere to such a diet. Since not everyone defines the Mediterranean diet in the same way, the researchers defined it as a diet that placed no restriction on total fat intake and included two or more of seven components: high monounsaturated-to-saturated fat ratio (for example, using olive oil as a main cooking ingredient), high fruit and vegetable intake, high consumption of legumes, high grain and cereal intake, moderate red wine consumption, moderate consumption of dairy products, and low consumption of meat and meat products with increased intake of fish.

Few randomized, controlled trials compared this type of diet to all others, but the few that did suggest that a Mediterranean diet with no restriction on fat intake may be associated with reduced incidence of cardiovascular events, breast cancer, and type 2 diabetes but does not affect all-cause mortality. The researchers found no studies that met their inclusion criteria to assess adherence outcomes, however, observational data reveal that total cancer incidence and mortality and colorectal and lung cancer incidence were lower in persons with the highest adherence to the Mediterranean diet compared to those with the lowest but show no association between Mediterranean diet adherence and breast cancer risk.

Thursday, July 14, 2016

Red meat consumption linked with increased risk of developing kidney failure

A new study indicates that red meat intake may increase the risk of kidney failure in the general population, and substituting red meat with alternative sources of protein from time to time may significantly reduce this risk. The findings appear in an upcoming issue of the Journal of the American Society of Nephrology (JASN).

Increasing numbers of individuals are developing chronic kidney disease (CKD), and many progress to end-stage renal disease (ESRD), which requires dialysis or a kidney transplant. Current guidelines recommend restricting dietary protein intake to help manage CKD and slow progression to ESRD; however, there is limited evidence that overall dietary protein restriction or limiting specific food sources of protein intake may slow kidney function decline in the general population.

To examine the relationship between dietary intake of major sources of protein and kidney function, a team led by Woon-Puay Koh, MBBS (Hons), PhD (Duke-NUS Medical School and Saw Swee Hock School of Public Health in National University of Singapore) analyzed data from the Singapore Chinese Health Study, a prospective study of 63,257 Chinese adults in Singapore. This is a population where 97% of red meat intake consisted of pork. Other food sources of protein included poultry, fish/shellfish, eggs, dairy products, soy, and legumes.

After an average follow-up of 15.5 years, the researchers found that red meat intake was strongly associated with an increased risk of ESRD in a dose-dependent manner. People consuming the highest amounts (top 25%) of red meat had a 40% increased risk of developing ESRD compared with people consuming the lowest amounts (lowest 25%) No association was found with intakes of poultry, fish, eggs, or dairy products, while soy and legumes appeared to be slightly protective. Substituting one serving of red meat with other sources of protein reduced the risk of ESRD by up to 62%.

"We embarked on our study to see what advice should be given to CKD patients or to the general population worried about their kidney health regarding types or sources of protein intake," said Dr. Koh. "Our findings suggest that these individuals can still maintain protein intake but consider switching to plant-based sources; however, if they still choose to eat meat, fish/shellfish and poultry are better alternatives to red meat."

Dietary restriction has beneficial effects on longevity

Dietary restriction, or limited food intake without malnutrition, has beneficial effects on longevity in many species, including humans. A new study from the Sanford Burnham Prebys Medical Discovery Institute (SBP), published today in PLoS Genetics, represents a major advance in understanding how dietary restriction leads to these advantages.

"In this study, we used the small roundworm C. elegans as a model to show that autophagy in the intestine is critical for lifespan extension," said Malene Hansen, Ph.D., associate professor in SBP's Development, Aging, and Regeneration Program and senior author of the study. "We found that the gut of dietary-restricted worms has a higher than normal rate of autophagy, which appears to improve fitness in multiple ways--preserving intestinal integrity and maintaining the animal's ability to move around."

Autophagy, or cellular recycling, is well known to play a role in lifespan extension. Autophagy involves breaking down the cell's parts--its protein-making, power-generating, and transport systems--into small molecules. This both eliminates unnecessary or broken cell machinery and provides building blocks to make new cell components, which is especially important when starting materials are not provided by the diet.

In this study the research team wanted to understand how dietary restriction impacts autophagy in the intestine, whose proper function is already known to be important for long life.

"The strain of worms we used, called eat-2, is genetically predisposed to eat less, and they live longer than normal worms, so they provide an ideal model in which to investigate how dietary restriction extends lifespan," said Sara Gelino, Ph.D., research associate in Hansen's lab and lead author of the study. "We found that blocking autophagy in their intestines significantly shortened their lifespans, showing that autophagy in this organ is key for longevity.

"These results led us to examine how inhibiting autophagy impacts the function of the intestine. We found that while normal worms' gut barriers become leaky as they get older, those of eat-2 worms remain intact. Preventing autophagy eliminated this benefit, which indicates that a non-leaky intestine is an important factor for long life."

"How intestinal integrity relates to longevity is not clearly understood," Hansen commented. "It's possible that the decline in the gut's barrier function associated with normal aging might let damaging substances or pathogens into the body."

The research team also observed that turning off autophagy in the intestine made the slow-eating, long-lived worms move around less.

"The decrease in physical activity indicates that autophagy in one organ can have a major impact on other organs, in this case probably muscle or motor neurons," said Hansen. "Finding the link between motility and autophagy in the intestine will require further research, but we speculate that inhibiting autophagy in the gut may impair the gut's ability to metabolize nutrients or secrete hormones important for the function of other organs."

While these results suggest that boosting autophagy in the gut is generally beneficial, Hansen cautions that further research is needed: "Before we can consider regulating autophagy to manage disease, we need to learn a lot more about how the process works both in a single cell as well as in the whole organism."

Many of these future studies will also employ C. elegans. "Even though worms are much simpler than humans, many of the same basic mechanisms drive their biology. The knowledge we gain from this fast-paced research could eventually contribute to the development of new treatments that help people live longer, healthier lives," added Hansen

Moderately reducing calories in non-obese people reduces inflammation

Eating less may help us lead longer, healthier lives, according to the new results from a large, multicenter study, led by researchers at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University. The paper, published in Aging, reveals that restricting calories by 25 percent in healthy non-obese individuals over two years, while maintaining adequate protein, vitamin, and mineral intake, can significantly lower markers of chronic inflammation without negatively affecting other parts of the immune system.

"Previous studies in animals and simple model organisms over the past 85 years have supported the notion that calorie restriction can increase the lifespan by reducing inflammation and other chronic disease risk factors, but with mixed results about whether it has a negative or null effect on cell-mediated immune responses," said first and corresponding author Simin Nikbin Meydani, D.V.M., Ph.D., director of the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts (HNRCA) and the director of its Nutritional Immunology Laboratory. "This is the first study to examine these effects over two years on healthy, normal- or slightly over- weight individuals and observe that caloric restriction reduces inflammation without compromising other key functions of the immune system such as antibody production in response to vaccines."

Chronic inflammation has been shown to create successions of destructive reactions that damage cells, thus playing a major role in the development of age-related diseases such as cancer, heart disease, and dementia. According to the Centers for Disease Control and Prevention (CDC), seven of the top 10 causes of death in 2010 were chronic diseases, with heart disease and cancer accounting for nearly 48 percent of all deaths. The CDC also reports in that same year 86 percent of all health care spending was for people with one or more chronic medical conditions.

After six weeks of baseline testing, which included metabolic measurements to determine their total daily energy expenditure, and blood collection to evaluate inflammation and cell-mediated immunity markers, 220 eligible individuals were randomized into two groups and further stratified by site, sex, and body mass index.

The control group maintained their normal diet for the duration of the study, while the test group was provided with support to maintain a high-satiety diet that restricted their calories by 25 percent including customized behavioral guidance. The test group was also given multivitamin and mineral supplements to prevent micronutrient malnutrition. To maintain a 25 percent reduction in calories the test group's calorie prescriptions were reduced three times through the two-year study to coincide with their weight loss based on body fat, and muscle mass calculations.

Both inflammation and immunity biomarkers were measured at baseline, 12 months, and at 24 months. Response to vaccines was determined at the end of the study. As an indicator of susceptibility to infectious disease, cell-mediated immunity was measured by antibody response to three vaccines and skin prick tests, white blood cell count, and self-reported illness. In addition, inflammation was monitored using serum levels of common inflammatory markers, including C-reactive protein, TNF alpha, and leptin.

The research team found that the test group had a significant and persistent reduction in inflammatory markers with no discernible difference in immune responses from the control group at the end of 24 months. However, while reduction in weight, fat mass, and leptin levels were most pronounced at 12 months they were not accompanied by the significant reduction in C-reactive protein and TNF alpha, both indicators of inflammation, until 24 months. This delay suggests that long-term calorie restriction, at least 24 months, induces other mechanisms that may play a role in the reduction of inflammation.

"This may be one of the most powerful non-genetic intervention to slow aging, increase our health span and the quality of our lives," continued Meydani of the HRNCA. She is also a professor at the Friedman School of Nutrition Science and Policy, Tufts University School of Medicine, and a member of the immunology program faculty at the Sackler School of Graduate Biomedical Sciences at Tufts.

"These calorie restricted changes suggest a shift toward a healthy phenotype given the established role of inflammation in the development of cardiovascular disease, cancer and aging. With all of today's fitness and biometric measurement technology available to the public, it is certainly feasible for the average person to maintain a 10-15 percent calorie restriction as a strategy for long-term health benefits," said co-author Luigi Fontana, M.D., Ph.D., professor of medicine and nutrition at Washington University in St. Louis and Brescia University (Italy).

The inability to remember details is not an indicator of decline in brain function

The inability to remember details, such as the location of objects, begins in early midlife (the 40s) and may be the result of a change in what information the brain focuses on during memory formation and retrieval, rather than a decline in brain function, according to a study by McGill University researchers.

Senior author Natasha Rajah, Director of the Brain Imaging Centre at McGill University's Douglas Institute and Associate Professor in McGill's Department of Psychiatry, says this reorientation could impact daily life. "This change in memory strategy with age may have detrimental effects on day-to-day functions that place emphasis on memory for details such as where you parked your car or when you took your prescriptions."

Brain changes associated with dementia are now thought to arise decades before the onset of symptoms. So a key question in current memory research concerns which changes to the aging brain are normal and which are not. But Dr. Rajah says most of the work on aging and memory has concentrated on understanding brain changes later in life. "So we know little about what happens at midlife in healthy aging and how this relates to findings in late life. Our research was aimed at addressing this issue."

In this study, published in the journal, NeuroImage, 112 healthy adults ranging in age from 19 to 76 years were shown a series of faces. Participants were then asked to recall where a particular face appeared on the screen (left or right) and when it appeared (least or most recently). The researchers used functional MRI to analyze which parts of brain were activated during recall of these details.

Rajah and colleagues found that young adults activated their visual cortex while successfully performing this task. As she explains, "They are really paying attention to the perceptual details in order to make that decision." On the other hand, middle-aged and older adults didn't show the same level of visual cortex activation when they recalled the information. Instead, their medial prefrontal cortex was activated. That's a part of the brain known to be involved with information having to do with one's own life and introspection.

Even though middle-aged and older participants didn't perform as well as younger ones in this experiment, Rajah says it may be wrong to regard the response of the middle-aged and older brains as impairment. "This may not be a 'deficit' in brain function per se, but reflects changes in what adults deem 'important information' as they age." In other words, the middle-aged and older participants were simply focusing on different aspects of the event compared to those in the younger group.
Rajah says that middle-aged and older adults might improve their recall abilities by learning to focus on external rather than internal information. "That may be why some research has suggested that mindfulness meditation is related to better cognitive aging."

Rajah is currently analyzing data from a similar study to discern if there are any gender differences in middle-aged brain function as it relates to memory. "At mid-life women are going through a lot of hormonal change. So we're wondering how much of these results is driven by post-menopausal women."

Best diets focus on healthy foods you really enjoy eating

Many diet plans are doomed from the start.

The reason? Dieters tend to adopt the wrong strategies, often planning to ditch their favorite foods and replace them with less-desirable options, according to new research from Baylor University's Hankamer School of Business.

Conversely, successful dieters focus on adding healthy foods -- foods that they actually like, said Meredith David, Ph.D., assistant professor of marketing at Baylor. She is the lead author on the study, "Saying 'No' to Cake or 'Yes' to Kale: Approach and Avoidance Strategies in Pursuit of Health Goals," published in the journal Psychology & Marketing.

"Our research shows that instead of creating rules to avoid one's favorite treats, dieters should focus on eating healthy foods that they enjoy," David said. "Dieters who restrict themselves from consuming the foods they love most may be setting themselves up for failure. Instead, they may be better off by allowing occasional 'treats' and focusing attention on healthy foods that they enjoy and making it a point to include those tasty, but healthy foods in their diet."

The outcomes of the research -- three studies and a total of 542 study participants -- hinged on a person's level of self-control.

"In coming up with plans to enhance one's health and well-being, low self-control individuals tend to set themselves up for a harder pathway to success by focusing on avoiding the very foods they find most tempting," David said. "Our data reveals that individuals who are generally more successful at reaching their goals tend to develop more motivating plans regarding the inclusion of healthy, well-liked items and the exclusion of unhealthy items that are not one's favorites."

The research found:
  • When asked to list specific rules that individuals might use to guide their food consumption, a large percentage of individuals listed rules that involve restricting and avoiding certain foods. This was particularly the case among low self-control individuals -- those who generally have less success in reaching their goals. Individuals who are generally more successful in goal pursuit tended to list rules that involved things they should approach and/or consume.
  • When thinking of unhealthy foods to avoid as a part of a diet, low self-control individuals think of foods that they really like -- their favorite snacks, and most tempting items. High self-control individuals think of foods that they like but could reasonably forgo.
  • When thinking of healthy foods to eat as a part of a diet, low self-control individuals think of foods they do not like, such as those that they find highly unpalatable (e.g., Brussels sprouts). High self-control individuals think of foods they enjoy eating (e.g., strawberries).
"Frequent attention is given to health advice surrounding well-intentioned lists of 'magical' foods that everyone should eat or practically 'poisonous' foods that people should avoid consuming," David said. "The next time you decide to go on a diet or seek to improve your health by altering your food consumption, opt for strategies that focus on including healthy foods in your diet, and focus specifically on those healthy foods that you really enjoy eating."

Tuesday, July 12, 2016

Lighter weights just as effective as heavier weights to gain muscle, build strength

New research from McMaster University is challenging traditional workout wisdom, suggesting that lifting lighter weights many times is as efficient as lifting heavy weights for fewer repetitions.

It is the latest in a series of studies that started in 2010, contradicting the decades-old message that the best way to build muscle is to lift heavy weights.

"Fatigue is the great equalizer here," says Stuart Phillips, senior author on the study and professor in the Department of Kinesiology. "Lift to the point of exhaustion and it doesn't matter whether the weights are heavy or light."

Researchers recruited two groups of men for the study--all of them experienced weight lifters--who followed a 12-week, whole-body protocol. One group lifted lighter weights (up to 50 per cent of maximum strength) for sets ranging from 20 to 25 repetitions. The other group lifted heavier weights (up to 90 per cent of maximum strength) for eight to 12 repetitions. Both groups lifted to the point of failure.

Researchers analyzed muscle and blood samples and found gains in muscle mass and muscle fibre size, a key measure of strength, were virtually identical.

"At the point of fatigue, both groups would have been trying to maximally activate their muscle fibres to generate force," says Phillips, who conducted the work with graduate students and co-authors Rob Morton and Sara Oikawa.

While researchers stress that elite athletes are unlikely to adopt this training regime, it is an effective way to get stronger, put on muscle and generally improve health.

"For the 'mere mortal' who wants to get stronger, we've shown that you can take a break from lifting heavy weights and not compromise any gains," says Phillips. "It's also a new choice which could appeal to the masses and get people to take up something they should be doing for their health."

Another key finding was that none of the strength or muscle growth were related to testosterone or growth hormone, which many believe are responsible for such gains.

"It's a complete falsehood that the short-lived rise in testosterone or growth hormone is a driver of muscle growth," says Morton. "It's just time to end that kind of thinking."

Researchers suggest, however, that more work remains to be done in this area, including what underlying mechanisms are at work and in what populations does this sort of program work.

The findings are published online in the Journal of Applied Physiology.

Estrogen patch in newly postmenopausal women may reduce Alzheimer's risk

Can estrogen preserve brain function and decrease the risk of Alzheimer's disease when given early in menopause? Newly postmenopausal women who received estrogen via a skin patch had reduced beta-amyloid deposits, the sticky plaques found in the brains of people with Alzheimer's disease, a Mayo Clinic study published this month in the Journal of Alzheimer's Disease found. Ultimately, these deposits harm neurons, leading to cognitive problems.

In the study, women with APOE e4 -- one form of the most common gene associated with late-onset Alzheimer's disease -- had lower levels of amyloid deposits.

"This study showed, for the first time, that the brain amyloid deposition -- a hallmark of Alzheimer's disease -- is reduced in newly postmenopausal women who received 17beta-Estradiol patch form of hormone therapy," says lead author Kejal Kantarci, M.D., a Mayo Clinic radiologist. "Women with APOE e4, who have a greater genetic risk for Alzheimer's disease, particularly benefited from this therapy."

Menopause is defined as occurring 12 months after a woman's last menstrual period and marks the end of menstrual cycles. In the U.S., the average age of menopause is 51. A rapid decline in estrogen with menopause may be associated with an increased risk of Alzheimer's disease risk in women.

The Women's Health Initiative study by the National Institutes of Health (NIH) reported that menopausal hormone therapy started in women 65 or older increased the risk of dementia. In contrast, the multicenter Kronos Early Estrogen Prevention Study tested the hypothesis that healthy and younger women would respond to menopausal hormone therapy more favorably.

The Mayo Clinic study used data from the Kronos study to determine the effects of menopausal hormone therapy shortly after menopause, during the critical window of rapid estrogen depletion -- five to 36 months past menopause. Researchers investigated the brain amyloid deposition in 68 women ages 42 to 59 who participated in the Kronos trial during this critical window. The researchers used positron emission tomography, also known as a PET scan, to look for the brain amyloid deposits three years after the trial ended.

Of the 68 women, 21 received estrogen via a skin patch, 17 received estrogen orally and 30 received a placebo. Amyloid deposition was lower in women who received the patch, compared to the placebo, and the effect was most apparent in women with the APOE e4 genotype. The oral treatment was not associated with lower amyloid deposition.

The authors are seeking funding to perform amyloid PET imaging at eight more Kronos Early Estrogen Prevention study sites around the U.S.

"If our results are confirmed in the larger group of women, this finding has the potential to change the concepts for preventive interventions that drive the Alzheimer's disease field today," Dr. Kantarci says. "It also may have a significant impact on women making the decision to use hormone therapy in the early postmenopausal years."

Consuming probiotics promotes weight loss, reduces BMI

Consuming probiotics, so-called 'good bacteria', can reduce body weight and body mass index (BMI) according to a new meta-analysis published in the International Journal of Food Sciences and Nutrition.

The digestive health benefits of probiotics have been widely debated. Probiotic supplements, often added to yoghurts, may support general wellbeing in addition to improving immunity. However, evidence for the beneficial effects of probiotics has been lacking.

Researchers from the Department of Cardiology, Taizhou People's Hospital, Taizhou, China combined the findings of 25 randomized human trials investigating the impact of probiotic consumption on body weight and BMI in over 1,900 healthy adults. They found taking probiotics reduced BMI and body weight with the greatest reduction in BMI occurring in overweight adults. Interestingly, ingesting more than one type of probiotic and taking probiotics for 8 weeks or more resulted in increased weight loss.

"To date, quite a few researchers have investigated the effects of probiotics on body weight and BMI, without a consistent result," lead author Qingqing Zhang notes. What is significant about this study is, that based on findings from the 25 included trials, the researchers found that consumption of probiotics did lead to a modest decrease in body weight and BMI.

Although the amount of weight loss documented in this study was minimal, even a small reduction can have enormous public health benefits by reducing weight-related diseases such as Type 2 diabetes and high blood pressure.

Monday, July 11, 2016

Running barefoot helps optimize technique, reduces risk of injury

Scientists from the Universities of Granada and Jaén have demonstrated how barefoot running, when done properly, can considerably decrease the risk of injury as it produces significant changes to foot strike patterns, regardless of the speed of the runner.

Barefoot running appears to contribute to the acquisition of a more efficient biomechanical running pattern, allowing contact between the foot and the ground to begin in the metatarsal area (forefoot strikes). The use of standard modern footwear appears to favour the opposite technique; initiating contact with the ground at the heel area with a rearfoot strike, which produces significant impact peaks that negatively affect the runner's health and athletic performance.

There is currently a great deal of interest in the barefoot running trend, which is supported by a growing number of runners and researchers who are attempting to gain a better understanding of the advantages and disadvantages of this type of locomotion. While not currently accepted as the norm, the practice is on the rise.

Footwear worn by human beings over recent millennia can be categorised as clearly minimalist. Its fundamental feature was the introduction of a protective sole. Over the last three decades, several advances have radically changed the design of functional elements in athletic footwear: cushioned midsoles, movement control technology, technology for optimizing shock absorption, etc. The advantages of these recent technological advances in athletic footwear are disputed in scientific forums.

A twelve-week program

The benefits of barefoot running are attainable only when one acquires certain techniques. Otherwise, barefoot running can give rise to other risk factors. One should therefore take precautions before starting to practice the activity.

A multidisciplinary UGR research team known as HUMAN LAB participated in the study. The team is located at the University of Granada's Sport and Health Institute (iMUDS), which is equipped with the most up to date and advanced technology for conducting comprehensive analyses of the health and efficiency indicators of the runners.

The study has been published in the Journal of Sport and Health Science. The article compiles the results obtained by researchers following the development of a training program based on 12 weeks of barefoot running designed to test the effects produced on runners.

The study was conducted with 39 volunteer runners who took part in a program consisting of specific exercises, completed in progressively increasing volumes on grass. The exercises were based exclusively on continual running, separated intervals and sprints.

Following the training period, the researchers found that athletes who run barefoot significantly adjust the way their feet initially make contact with the ground. Thanks to the program, runners with a rearfoot strike pattern significantly adjusted their strike pattern towards a forefoot strike pattern, both at comfortable running speeds (rearfoot support dropped from 55.6% to just 11.1%) and higher speeds (rearfoot support dropped from 58.3% to 13.8%).

Other significant results pertain to injury risk. The researchers found that internal foot eversion remained constant while foot and ankle rotation, however, varied between a 5.5%-13.8% increase in external rotation.

Changes in strike pattern

"The mechanical behaviour in the lower extremities, together with an excessive transversal movement of the ankle, appear to be closely linked to the development of chronic injury," explains Professor Víctor Manuel Soto Hermoso from the Department of Physical and Sports Education at UGR, who is one of the authors of the study.

In light of the results, Soto points out: "Training based on barefoot running, practised correctly, produces significant changes in foot support, regardless of the athlete's speed: forefoot support (metatarsal), tends to minimize impact peaks and, therefore, leads to a lower risk of injury."
Nevertheless, the authors point out that athletes should be careful when beginning the practice of barefoot running. They recommend conducting a multidisciplinary study of the biomechanics of the musculoskeletal system both at the static (podiatric and postural) as well as dynamic (ambulatory and running locomotion) levels. Considerable importance should be given to the evaluation of three-dimensional kinematic changes (technique analysis), kinetics (force analysis) and biostructural changes (analysis of elastic and contractile elements) in addition to an analysis of commonly used footwear.

Soto concludes: "Professionals in the Sport Sciences field, working in cooperation with other health professionals, can design personalised programs in order to progressively introduce individuals to this fascinating and stimulating form of locomotion, the benefits of which -- whether as an occasionally employed resource, a training technique, or as a standard intensive practice -- are worth testing."

Eating more fruit and vegetables can substantially increase people's later happiness levels.

University of Warwick research indicates that eating more fruit and vegetables can substantially increase people's later happiness levels.

Published in the American Journal of Public Health, the study is one of the first major scientific attempts to explore psychological well-being beyond the traditional finding that fruit and vegetables can reduce risk of cancer and heart attacks.

Happiness benefits were detected for each extra daily portion of fruit and vegetables up to 8 portions per day.

The researchers concluded that people who changed from almost no fruit and veg to eight portions of fruit and veg a day would experience an increase in life satisfaction equivalent to moving from unemployment to employment. The well-being improvements occurred within 24 months.


The study followed more than 12,000 randomly selected people. These subjects kept food diaries and had their psychological well-being measured. The authors found large positive psychological benefits within two years of an improved diet.

Professor Andrew Oswald said: "Eating fruit and vegetables apparently boosts our happiness far more quickly than it improves human health. People's motivation to eat healthy food is weakened by the fact that physical-health benefits, such as protecting against cancer, accrue decades later. However, well-being improvements from increased consumption of fruit and vegetables are closer to immediate."

The work is a collaboration between the University of Warwick, England and the University of Queensland, Australia. The researchers found that happiness increased incrementally for each extra daily portion of fruit and vegetables up to eight portions per day. The study involved an examination of longitudinal food diaries of 12,385 randomly sampled Australian adults over 2007, 2009, and 2013 in the Household, Income, and Labour Dynamics in Australia Survey. The authors adjusted the effects on incident changes in happiness and life satisfaction for people's changing incomes and personal circumstances.

Western diet

The study has policy implications, particularly in the developed world where the typical citizen eats an unhealthy diet. The findings could be used by health professionals to persuade people to consume more fruits and vegetables.

Dr Redzo Mujcic, research fellow at the University of Queensland, said: "Perhaps our results will be more effective than traditional messages in convincing people to have a healthy diet. There is a psychological payoff now from fruit and vegetables -- not just a lower health risk decades later."

The authors found that alterations in fruit and vegetable intake were predictive of later alterations in happiness and satisfaction with life. They took into account many other influences, including changes in people's incomes and life circumstances. One part of the study examined information from the Australian Go for 2&5 Campaign. The campaign was run in some Australian states which have promoted the consumption of two portions of fruit and five portions of vegetables each day.


The academics think it may be possible eventually to link this study to current research into antioxidants which suggests a connection between optimism and carotenoid in the blood. However they argue that further research is needed in this area.

Saturday, July 9, 2016

The benefits of exercise during pregnancy

Researchers collected and re-examined clinical trial data on exercise during pregnancy and whether it plays a role in preterm birth, and found that exercise is safe and does not increase the risk of preterm birth. In addition, women who exercised were less likely to have a C-section than those who did not. The study was published in the American Journal of Obstetrics & Gynecology.

Historically, women were discouraged from vigorous exercise during pregnancy because of the risk of preterm birth. "The thinking was that exercise releases norepinephrine in the body, which is a chemical that can stimulate contractions of the uterus, and thus lead to preterm birth," says senior author on the study Vincenzo Berghella, M.D., Director of Maternal Fetal Medicine and Professor at the Sidney Kimmel Medical College at Thomas Jefferson University. "But numerous studies including this new meta-analysis, have since shown that exercise does not harm the baby, and can have benefits for the mom and baby."

Dr. Berghella and his co-authors pooled data from nine randomized controlled studies - one of the strongest types studies involving human subjects - in which pregnant women were divided into two groups. Of the 2,059 women who were included in the analysis, about half (1,022 women) exercised for 35-90 minutes 3-4 times per week for 10 weeks or up until their delivery, whereas the other half, (1,037 women) engaged in no exercise.

The researchers found that there was no significant increase in preterm birth, defined as delivery before 37 weeks, in women who exercised than in those who did not. There were, however, a few benefits. Women who exercised were more likely to deliver vaginally - 73 percent of exercising women delivered vaginally whereas 67 percent of non-exercising women delivered vaginally. Likewise, there was a lower incidence of C-section in women who exercised during pregnancy - 17 percent of exercising women had a C-section versus 22 percent in those who did not. There was also lower incidence of gestational diabetes, and lower rates of high blood pressure in the exercising group.

All of the women included in this analysis were carrying a single baby (not twins), had normal weight to start with, and had no health conditions that prevented them from exercising.

"The results of this analysis support current guidelines from the American Congress of Obstetricians and Gynecologists (ACOG), which sets the recommendations for our field," says Dr. Berghella. "However, there are many reasons women pull back on exercise during pregnancy - discomfort, an increase in tiredness and feeling winded by low level exertion. This paper reinforces that exercise is good for the mom and the baby and does not hold any increased risk preterm birth."