Skip to content

Category: healthy living

Published on

Research reports and articles on the benefits of exercise have been piling up. Here are some worth looking at. From Science Daily:

Sitting too much, not just lack of exercise, is detrimental to cardiovascular health

Cardiologists have found that sedentary behaviors may lower cardiorespiratory fitness levels. New evidence suggests that two hours of sedentary behavior can be just as harmful as 20 minutes of exercise is beneficial.

From Science Daily:

Out of shape? Your memory may suffer

Here's another reason to drop that doughnut and hit the treadmill: A new study suggests aerobic fitness affects long-term memory. "The findings show that lower-fit individuals lose more memory across time," said a co-author. The study is one of the first to investigate young, supposedly healthy adults. 

From Science Daily:

Less exercise, not more calories, responsible for expanding waistlines

Sedentary lifestyle and not caloric intake may be to blame for increased obesity in the US, according to a new analysis. A study reveals that in the past 20 years there has been a sharp decrease in physical exercise and an increase in average body mass index (BMI), while caloric intake has remained steady. 

From Science Daily:

Older adults: Build muscle and you'll live longer

The more muscle mass older Americans have, the less likely they are to die prematurely, new research shows. The findings add to the growing evidence that overall body composition -- and not the widely used body mass index, or BMI -- is a better predictor of all-cause mortality. "In other words, the greater your muscle mass, the lower your risk of death," said the study's co-author. "Thus, rather than worrying about weight or body mass index, we should be trying to maximize and maintain muscle mass."

From Medical Xpress:

Keeping active pays off in your 70s and 80s

Older people who undertake at least 25 minutes of moderate or vigorous exercise everyday need fewer prescriptions and are less likely to be admitted to hospital in an emergency, new research has revealed.

Researchers from the Universities of Bath, Bristol and UWE-Bristol looked at data from 213 people whose average age was 78. Of people studied, those who carried out more than 25 minutes of moderate to vigorous physical activity per day – such as walking quickly, cycling or swimming - received 50 per cent fewer prescriptions than those who were more active over a four to five year period.

Such physical activity leads to a higher metabolism and better circulation, reducing the risk of conditions and diseases common in older age such as high blood presure, type 2 diabetes, coronary heart disease, and strokes.

From Everyday Health:

The Best Anti-Aging Medicine? Exercise

Everyone knows that exercise is good for you — it helps manage weight, improves muscle and bone strength, and even lifts your spirits. It can also add years to your life.“People have been looking for the secret to a long and healthy life for millennia,” said Neil Resnick, MD, chief of the division of geriatrics and director of the University of Pittsburgh Institute on Aging. “It turns out the most powerful intervention is exercise.”

A recent study conducted at Harvard found that exercise can be at least as effective as prescription drugs when it comes to preventing common conditions such as heart disease, stroke, and diabetes.

Exercise at any age is beneficial. From Science Daily:

Seniors who exercise regularly experience less physical decline as they age

Older adults in retirement communities who reported more exercise experienced less physical decline than their peers who reported less exercise, although many adults -- even those who exercised -- did not complete muscle-strengthening exercises, which are another defense against physical decline.

Published on

New discoveries of what is going on in our intestines, plus a new vocabulary to understand it all. Yes, it all is amazingly complex. Bottom line: we have complex communities (bacteria, bacterial viruses or bacteriophages, etc.) living and interacting in our intestines. And only with state-of-the-art genetic analysis (DNA sequencing) can we even "see" what is going on. I highlighted really important items in bold type. From Medical Xpress:

Researchers uncover new knowledge about our intestines

Researchers from Technical University of Denmark Systems Biology have mapped 500 previously unknown microorganisms in human intestinal flora as well as 800 also unknown bacterial viruses (also called bacteriophages) which attack intestinal bacteria.

"Using our method, researchers are now able to identify and collect genomes from previously unknown microorganisms in even highly complex microbial societies. This provides us with an overview we have not enjoyed previously," says Professor Søren Brunak who has co-headed the study together with Associate Professor Henrik Bjørn Nielsen.

So far, 200-300 intestinal bacterial species have been mapped. Now, the number will be more than doubled, which could significantly improve our understanding and treatment of a large number of diseases such as type 2 diabetes, asthma and obesity.

The two researchers have also studied the mutual relations between bacteria and viruses. Previously, bacteria were studied individually in the laboratory, but researchers are becoming increasingly aware that in order to understand the intestinal flora, you need to look at the interaction between the many different bacteria found.

And when we know the intestinal bacteria interactions, we can potentially develop a more selective way to treat a number of diseases. "Ideally we will be able to add or remove specific bacteria in the intestinal system and in this way induce a healthier intestinal flora," says Søren Brunak.

From Science Daily:

Revolutionary approach to studying intestinal microbiota

Analyzing the global genome, or the metagenome of the intestinal microbiota, has taken a turn, thanks to a new approach to study developed by an international research team. This method markedly simplifies microbiome analysis and renders it more powerful. The scientists have thus been able to sequence and assemble the complete genome of 238 intestinal bacteria, 75% of which were previously unknown. 

Research carried out in recent years on the intestinal microbiota has completely overturned our vision of the human gut ecosystem. Indeed, from "simple digesters" of food, these bacteria have become major factors in understanding certain diseases such as obesity, type 2 diabetes, or Crohn's disease. Important and direct links have also been demonstrated between these bacteria and the immune system, as well as with the brain. It is estimated that 100,000 billion bacteria populate the gut of each individual (or 10 to 100 times more than the number of cells in the human body), and their diversity is considerable, estimated to around a thousand different bacterial species in the intestinal human metagenome. However, because only 15% of these bacteria were previously isolated and characterized by genome sequencing, an immense number of the microbial genes previously identified still need to be assigned to a given species.

An analysis of 396 stool samples from Danish and Spanish individuals allowed the researchers to cluster these millions of genes into 7381 co-abundance groups of genes. Approximately 10% of these groups (741) corresponded to bacterial species referred to as metagenomic species (MGS); the others corresponded to bacterial viruses (848 bacteriophages were discovered), plasmids (circular, bacterial DNA fragments) or genes which protected bacteria from viral attack (known as CRISPR sequences). 85% of these MGS constituted unknown bacteria species (or ~630 species).

Using this new approach, the researchers succeeded in reconstituting the complete genome of 238 of these unknown species, without prior culture of these bacteria. Living without oxygen, in an environment that is difficult to characterise and reproduce, most of these gut bacteria cannot be cultured in the laboratory. 

The authors also demonstrated more than 800 dependent relationships within the 7381 gene co-abundance groups; this was the case, for example, of phages which require the presence of a bacterium to survive. These dependent relationships thus enable a clearer understanding of the survival mechanisms of a micro-organism in its ecosystem. 

Published on

Some good foods to eat for their health benefits. The following articles are from Science Daily:

Almonds reduce the risk of heart disease, research shows

Eating almonds can reduce the risk of heart disease by keeping blood vessels healthy, research has shown. Research found that they significantly increase the amount of antioxidants in the blood stream, reduce blood pressure and improve blood flow. These findings add weight to the theory that Mediterranean diets with lots of nuts have big health benefits... "Our study confirms that almonds are a superfood. Previous studies have shown that they keep your heart healthy, but our research proves that it isn't too late to introduce them into your diet -- adding even a handful (around 50g) every day for a short period can help.

Could grapefruit be good for your kidneys?

A natural product found in grapefruit can prevent kidney cysts from forming, new research indicates. Naringenin, which is also present in other citrus fruits, has been found to successfully block the formation of kidney cysts, an effect that occurs in polycystic kidney disease, by regulating the PKD2 protein responsible for the condition. With few treatments currently available, symptoms include high blood pressure and loss of kidney function, and lead to the need for dialysis.

More evidence that dark chocolate is good for you. From Science Daily:

Polyphenols could yield small benefit for people with PAD

In a small study, people with artery problems in their legs (peripheral artery disease) walked a little longer and farther when they ate dark chocolate -- a food rich in polyphenols.The authors suggest that compounds found in cocoa -- polyphenols -- may reduce oxidative stress and improve blood flow in peripheral arteries....Many other polyphenol-rich foods would offer less added sugar, saturated fats, and calories than dark chocolate, such as cloves, dried peppermint, celery seed, capers, and hazelnuts, to name a few.

Published on
Lactobacilli

The human vagina is another microbial community that is nowhere as simple as earlier thought - and it's not just Lactobacillus bacteria.

From The Scientist: Characterizing the “Healthy” Vagina

For years, researchers characterized the microbial community of women’s vaginas as being dominated by Lactobacillus bacteria, which ferment carbohydrates to lactic acid, yielding a low pH that is toxic to many pathogenic microbes. When levels of Lactobacillus drop, the pH becomes more neutral, and the risk of infection rises.

But with research revealing notable variation among women’s vaginal microbiomes, as well as some interesting dynamics of the microbial communities within a single organ, “that dogma is changing a little bit,” said Gregory Buck of the Vaginal Microbiome Consortium at Virginia Commonwealth University (VCU).

The composition and stability of the vaginal microbiome varies by race, age, even within an individual—and it’s quickly become clear that the formula for a “normal,” “healthy” microbial community cannot be computed by ratios of bacterial species. “In the past we’ve made some generalizations about what kinds of bacteria are found in the vagina, what kinds of bacteria are good or healthy or protective,” said microbial ecologist Larry Forney of the University of Idaho. “What the research is showing is there are tremendous differences between women in terms of the kinds of bacteria that are present and the changes in the communities that occur over time.”

In June 2010, Forney, Jacques Ravel of the University of Maryland School of Medicine, and their collaborators published a survey of the vaginal microbiomes of nearly 400 women and found that the majority harbored bacterial communities dominated by one of four Lactobacillus strains. More than a quarter of the women studied, however, did not follow this pattern. Instead, their vaginas had fewer Lactobacillus and greater numbers of other anaerobic bacteria, although the bacterial communities always included members of genera known to produce lactic acid.

In many ways, the microbiome of these women resembled the bacterial communities of women suffering from bacterial vaginosis (BV), an infection characterized by an odorous vaginal discharge, Buck noted. “By looking at the microbial components, you’d say they have BV, but they have no clinical symptoms,” he said. “These people are not unhealthy.”

The researchers also found that the composition of a woman’s vaginal microbiome was linked to her race. Eighty percent of Asian women and nearly 90 percent of white women harbored vaginal microbiomes that were dominated by Lactobacillus, while only about 60 percent of Hispanic and black women did. Moreover, vaginal pH varied with ethnicity as well, with Hispanic and black women averaging 5.0 and 4.7, respectively, and Asian and white women averaging 4.4 and 4.2. 

This raises questions about the role of the commensal bacteria and risk of preterm labor , which has been linked to BV—and to low levels of Lactobacillus in particular—and is one-and-a-half times more common among African American women than Caucasian women.

Meanwhile, the researchers continue to sort through 40,000 swabs from more than 6,000 women to better characterize the bacterial communities living in the vagina. But Fettweis and her colleagues face a common problem in microbiome research. “In many samples, only a fraction of [the genetic sequences] align to anything we have in our databases,” she said. “So I think there’s still a lot of work to be done in terms of actually understanding: What are these organisms?”

Another question facing researchers probing the vaginal microbiome is how it is initially colonized. “Where do [the bacteria] come from?” said Forney.

Many suspect that the process occurs during vaginal childbirth. But the adolescent microbiome does not resemble that of a sexually mature woman, having far less Lactobacillus, leading some to suspect that there may be a second colonization of the vagina later in life. And if the birthing process is important to establish the vaginal microbiome, what happens in the case of C-sections? “We have more questions than answers,” Forney said.

The microbiome is also not stable later in life. It is now well known that the vaginal microbiome changes after menopause, containing fewer Lactobacillus than the vaginas of reproductive-aged women, with the notable exception of women on hormone-replacement therapies.

Moreover, recent research has revealed that the composition of the vaginal microbiome can change in as little as 24 hours.

The temporal dynamics of the vaginal microbiome raise important questions about developing microbiota-based diagnostics and therapeutics, said Forney. “If you perform a diagnostic test, would you get a different result tomorrow or the day after? In some cases, yes. How do you incorporate that into [a] decision about whether some kind of intervention is required?”

Published on

Informing pregnant women about environmental health hazards is absolutely necessary, especially because steps can be taken to avoid them (such as pesticides, mercury in fish, lead and BPA). Why isn't it happening routinely? Hey obstetricians - are you listening? From Huffington Post:

Doctors Fail To Counsel Pregnant Women On Toxic Chemical Risks

...dozens of environmental chemicals can course through a pregnant woman's body, cross the umbilical cord and wreck havoc on a developing fetus. Birth defects, IQ losses and childhood cancers are just some of the potential risks scientists have now tied to even low levels of exposure.

Among more than 2,500 doctors consulted for the survey, nearly all of them reported counseling patients on factors such as diet, exercise and cigarette smoking. However, only about 20 percent said they addressed environmental exposures. They pegged their hesitation to a number of factors, from the fear of overwhelming patients with anxiety-inducing worries to limited appointment time to a lack of environmental health education.

Just one in 15 doctors said they had received training on the harmful reproductive effects of toxic chemicals. "Medical school and residencies tend to frame their curriculum around the boards and required licensing exams," said Stotland. "This material is not yet on those tests." ... The American College of Obstetrics and Gynecologists (ACOG) and the American Society for Reproductive Medicine (ASRM) issued a statement in October that underscored mounting evidence of "significant and long-lasting effects" caused by industrial chemicals, and emphasized doctors' role in protecting pregnant women.

The actual study from Plos One summed up the importance of knowing about exposures to environmental hazards during pregnancy very nicely in the introduction:

Counseling Patients on Preventing Prenatal Environmental Exposures - A Mixed-Methods Study of Obstetricians

Exposure to hazardous environmental chemicals, i.e., manufactured chemicals and metals, is linked to adverse health outcomes across all stages of the human life cycle including fertility, conception, pregnancy, child and adolescent development, and adult health [1]–[5]. Human exposure to environmental chemicals is ubiquitous. A population-based study found that virtually all pregnant women in the U.S. had measureable levels of at least 43 different environmental chemicals in their bodies, including chemicals that were measured at levels similar to those associated with adverse developmental and reproductive health outcomes in epidemiologic studies [6]. There are currently over 80,000 chemicals in commerce [7], [8], and exposure occurs through air, water, food and consumer products in the home and workplace. The majority of industrial chemicals have not been tested for potential reproductive/developmental harm [9].

Obstetricians are uniquely positioned to help prevent exposures to environmental chemicals with adverse developmental and reproductive health effects [2]. Pregnancy is a time when exposure to environmental contaminants can disrupt or interfere with the physiology of a cell, tissue, or organ [4], leading to permanent and lifelong adverse health outcomes that may be passed down to future generations [10]. Pregnancy is also an opportune time to prevent harmful exposures as it is a period when patient interest about health can be extremely high.

Published on

The worrisome results are adding up for BPA and BPS. From Environmental Health News:

Miscarriage risk rises with BPA exposure, study finds

Women exposed to high levels of bisphenol A early in their pregnancy had an 83 percent greater risk of miscarriage than women with the lowest levels, according to new research. The scientists said their new study adds to evidence that low levels of the ubiquitous chemical, used to make polycarbonate plastic and found in some food cans and paper receipts, may affect human reproduction. The study involved 115 pregnant women who had visited a Stanford University fertility clinic within about four weeks of fertilization. The more BPA detected in the women’s blood, the higher their risk of miscarriage, according to the researchers.

“Couples suffering from infertility or recurrent miscarriages would be best advised to reduce BPA exposure because it has the potential to adversely affect fetal development,” wrote the scientists, led by Dr. Ruth Lathi, a Stanford University associate professor of obstetrics and gynecology. 

In 2005, a smaller study in Japan found that 45 women who had three or more first-trimester miscarriages had three times more BPA in their blood than 32 women with no history of pregnancy problems. 

From Science Daily:

BPA increases risk of cancer in human prostate tissue, study shows

Fetal exposure to a commonly used plasticizer found in products such as water bottles, soup can liners and paper receipts, can increase the risk for prostate cancer later in life, according to a study. Exposure of the fetus to BPA in utero is of particular concern, because the chemical, which mimics the hormone estrogen, has been linked to several kinds of cancer, including prostate cancer, in rodent models. The new findings show that human prostate tissue is also susceptible.

"Our research provides the first direct evidence that exposure to BPA during development, at the levels we see in our day-to-day lives, increases the risk for prostate cancer in human prostate tissue," Prins said

This study was done in rats, but thought to also apply to humans. From Science Daily:

Common BPA substitute, BPS, disrupts heart rhythms in females

Bisphenol S (BPS), a common substitute for bisphenol A (BPA) in consumer products, may have similar toxic effects on the heart as previously reported for BPA, a new study finds.

There is implied safety in BPA-free products. The thing is, the BPA analogs -- and BPS is one of them -- have not been tested for safety in humans." "Our findings call into question the safety of BPA-free products containing BPS," he said. "BPS and other BPA analogs need to be evaluated before further use by humans."

Published on

The study talked specifically about 3 types of bacteria that were different among the groups (severely obese, diabetics, healthy) studied: Firmicutes, Bifidobacteria, Clostridium leptum. From Science Daily:

Gut microbe levels are linked to type 2 diabetes and obesity

People with Type 2 diabetes or obesity have changes in the composition of their intestinal micro-organisms -- called the gut microbiota -- that healthy people do not have, researchers from Turkey have found.

The study lends support to other recent reports that have found an association between specific bacterial species in the human digestive system and obesity and diabetes, according to lead investigator Yalcin Basaran, MD, an endocrinologist from Gulhane Military Medical Academy School of Medicine, Ankara, Turkey.

The human digestive system contains an estimated 10 trillion to 100 trillion bacteria and other microscopic organisms, with each person housing at least 160 different species of organisms, according to Basaran. 

Basaran and his fellow researchers sought to identify the relationship between the gut microbe composition and obesity and Type 2 diabetes. Their study included 27 severely obese adults (20 men and seven women) whose body mass index, or BMI, exceeded 35 kg/m2, as well as 26 adults (18 men and eight women) with newly diagnosed Type 2 diabetes and 28 healthy control subjects (22 men and six women). 

Fecal analysis using a molecular biology technique showed that several of the most common types of bacteria in the gut were present at considerably lower levels in the obese and diabetic groups, compared with healthy controls. These reductions ranged from 4.2 to 12.5 percent in the obese patients and 10 to 11.5 percent in the diabetic patients, Basaran reported.

"Manipulation of intestinal bacteria could offer a new approach to manage obesity and Type 2 diabetes."

Published on

But I wonder if the results would be different if the only processed meat (cold cuts, salami, prosciutto) you ate came from antibiotic, hormone, additive, and nitrate-free meat. From Science Daily:

Processed red meat linked to higher risk of heart failure, death in men

Men who regularly eat moderate amounts of processed red meat such as cold cuts (ham/salami) and sausage may have an increased risk of heart failure incidence and a greater risk of death from heart failure. 

Processed meats are preserved by smoking, curing, salting or adding preservatives. Examples include cold cuts (ham, salami), sausage, bacon and hot dogs."Processed red meat commonly contains sodium, nitrates, phosphates and other food additives, and smoked and grilled meats also contain polycyclic aromatic hydrocarbons, all of which may contribute to the increased heart failure risk," said Alicja Wolk, D.M.Sc., senior author of the study and professor in the Division of Nutritional Epidemiology at the Institute of Environmental Medicine, Karolinska Institutet in Stockholm, Sweden. "Unprocessed meat is free from food additives and usually has a lower amount of sodium."

The Cohort of Swedish Men study -- the first to examine the effects of processed red meat separately from unprocessed red meat -- included 37,035 men 45-79 years old with no history of heart failure, ischemic heart disease or cancer. 

After almost 12 years of follow-up, researchers found:  - Men who ate the most processed red meat had more than a 2-fold increased risk of death from heart failure compared to men in the lowest category. - For each 50 gram (e.g. 1-2 slices of ham) increase in daily consumption of processed meat, the risk of heart failure incidence increased by 8 percent and the risk of death from heart failure by 38 percent. - The risk of heart failure or death among those who ate unprocessed red meat didn't increase.

"To reduce your risk of heart failure and other cardiovascular diseases, we suggest avoiding processed red meat in your diet, and limiting the amount of unprocessed red meat to one to two servings per week or less," said Joanna Kaluza, Ph.D., study lead author and assistant professor in the Department of Human Nutrition at Warsaw University of Life Sciences in Poland. "Instead, eat a diet rich in fruit, vegetables, whole grain products, nuts and increase your servings of fish."

Published on

For those who missed it. An amusing and informative personal story (Julia Scott) about trying to cultivate a healthy skin biome. Well worth reading. Excerpts from the May 22, 2014 NY Times:

My No-Soap, No-Shampoo, Bacteria-Rich Hygiene Experiment

For most of my life, if I’ve thought at all about the bacteria living on my skin, it has been while trying to scrub them away. But recently I spent four weeks rubbing them in. I was Subject 26 in testing a living bacterial skin tonic, developed by AOBiome, a biotech start-up in Cambridge, Mass. The tonic looks, feels and tastes like water, but each spray bottle of AO+ Refreshing Cosmetic Mist contains billions of cultivated Nitrosomonas eutropha, an ammonia-oxidizing bacteria (AOB) that is most commonly found in dirt and untreated water. AOBiome scientists hypothesize that it once lived happily on us too — before we started washing it away with soap and shampoo — acting as a built-in cleanser, deodorant, anti-inflammatory and immune booster by feeding on the ammonia in our sweat and converting it into nitrite and nitric oxide.

 Because the N. eutropha are alive, he said, they would need to be kept cold to remain stable. I would be required to mist my face, scalp and body with bacteria twice a day. I would be swabbed every week at a lab, and the samples would be analyzed to detect changes in my invisible microbial community.

While most microbiome studies have focused on the health implications of what’s found deep in the gut, companies like AOBiome are interested in how we can manipulate the hidden universe of organisms (bacteria, viruses and fungi) teeming throughout our glands, hair follicles and epidermis. They see long-term medical possibilities in the idea of adding skin bacteria instead of vanquishing them with antibacterials — the potential to change how we diagnose and treat serious skin ailments. 

For my part in the AO+ study, I wanted to see what the bacteria could do quickly, and I wanted to cut down on variables, so I decided to sacrifice my own soaps, shampoo and deodorant while participating. I was determined to grow a garden of my own. Some skin bacteria species double every 20 minutes; ammonia-oxidizing bacteria are much slower, doubling only every 10 hours. And now the bacteria were on my skin.

I had warned my friends and co-workers about my experiment, and while there were plenty of jokes — someone left a stick of deodorant on my desk; people started referring to me as “Teen Spirit” — when I pressed them to sniff me after a few soap-free days, no one could detect a difference. Aside from my increasingly greasy hair, the real changes were invisible. By the end of the week, Jamas was happy to see test results that showed the N. eutropha had begun to settle in, finding a friendly niche within my biome.

AOBiome is not the first company to try to leverage emerging discoveries about the skin microbiome into topical products. The skin-care aisle at my drugstore had a moisturizer with a “probiotic complex,” which contains an extract of Lactobacillus, species unknown. There is even a “frozen yogurt” body cleanser whose second ingredient is sodium lauryl sulfate, a potent detergent, so you can remove your healthy bacteria just as fast as you can grow them.

Although a few studies have shown that Lactobacillus may reduce symptoms of eczema when taken orally, it does not live on the skin with any abundance, making it “a curious place to start for a skin probiotic,” said Michael Fischbach, a microbiologist at the University of California, San Francisco. Extracts are not alive, so they won’t be colonizing anything.

It doesn’t help that the F.D.A. has no regulatory definition for “probiotic” and has never approved such a product for therapeutic use. “The skin microbiome is the wild frontier,” Fischbach told me. “We know very little about what goes wrong when things go wrong and whether fixing the bacterial community is going to fix any real problems.”

I asked AOBiome which of my products was the biggest threat to the “good” bacteria on my skin. The answer was equivocal: Sodium lauryl sulfate, the first ingredient in many shampoos, may be the deadliest to N. eutropha, but nearly all common liquid cleansers remove at least some of the bacteria. Antibacterial soaps are most likely the worst culprits, but even soaps made with only vegetable oils or animal fats strip the skin of AOB.

Published on

The reduced risk of stroke was from only a modest 20 grams of protein per day. From Science Daily:

Diet higher in protein may be linked to lower risk of stroke

People with diets higher in protein, especially from fish, may be less likely to have a stroke than those with diets lower in protein, according to a meta-analysis. The meta-analysis looked at all of the available research on the relationship between protein in the diet and the risk of stroke. Seven studies with a total of 254,489 participants who were followed for an average of 14 years were included in the analysis.

"The amount of protein that led to the reduced risk was moderate -- equal to 20 grams per day," said study author Xinfeng Liu, MD, PhD, of Nanjing University School of Medicine in Nanjing, China. 

Overall, the participants with the highest amount of protein in their diets were 20 percent less likely to develop a stroke than those with the lowest amount of protein in their diets. The results accounted for other factors that could affect the risk of stroke, such as smoking and high cholesterol. For every additional 20 grams per day of protein that people ate, their risk of stroke decreased by 26 percent.

Liu noted that the analysis does not support increased consumption of red meat, which has been associated with increased stroke risk. Two of the studies were conducted in Japan, where people eat less red meat than westerners do and more fish, which has been associated with decreased risk of stroke. 

The reduced risk of stroke was stronger for animal protein than vegetable protein. Protein has the effect of lowering blood pressure, which may play a role in reducing stroke risk, Liu said.