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 A plant-based diet (eating lots of plant foods - fruits, vegetables, whole grains, legumes, seeds and nuts) once again shows health benefits in a new study - here a lower incidence of type 2 diabetes. But what kind of plant-based foods one eats is important: consumption of a plant-based diet that emphasized healthy plant foods was associated with a larger decrease (34%) in diabetes risk, while consumption of a plant-based diet high in less healthy plant foods (soda, fruit juices, sweets/desserts, refined grains) was associated with a 16% increased diabetes risk. From Medical Xpress:

Healthy plant-based diet linked with substantially lower type 2 diabetes risk

Consuming a plant-based diet—especially one rich in high-quality plant foods such as whole grains, fruits, vegetables, nuts, and legumes—is linked with substantially lower risk of developing type 2 diabetes, according to a new study from Harvard T.H. Chan School of Public Health.

While previous studies have found links between vegetarian diets and improved health outcomes, including reduced risk of type 2 diabetes, this new study is the first to make distinctions between healthy plant-based diets and less healthy ones that include things like sweetened foods and beverages, which may be detrimental for health. The study also considered the effect of including some animal foods in the diet.

The researchers followed more than 200,000 male and female health professionals across the U.S. for more than 20 years who had regularly filled out questionnaires on their diet, lifestyle, medical history, and new disease diagnoses as part of three large long-term studies. The researchers evaluated participants' diets using a plant-based diet index in which they assigned plant-derived foods higher scores and animal-derived foods lower scores.

The study found that high adherence to a plant-based diet that was low in animal foods was associated with a 20% reduced risk of type 2 diabetes compared with low adherence to such a diet. Eating a healthy version of a plant-based diet was linked with a 34% lower diabetes risk, while a less healthy version—including foods such as refined grains, potatoes, and sugar-sweetened beverages—was linked with a 16% increased risk. Even modestly lowering animal food consumption—for example, from 5-6 servings per day to about 4 servings per day—was linked with lower diabetes incidence, the study found.

The researchers suggested that healthful plant-based diets could be lowering type 2 diabetes risk because such diets are high in fiber, antioxidants, unsaturated fatty acids, and micronutrients such as magnesium, and are low in saturated fat. Healthy plant foods may also be contributing to a healthy gut microbiome, the authors said.

The following article excerpts are from the talk "Food and Brain" about the best foods for the brain, at the annual 2015 meeting of the American Psychiatric Association (APA). This is in the new emerging field of food psychiatry, or how certain foods and diet influence the brain. The data is emerging that we can positively influence mental health through dietary interventions. For ex.: recent work reported that adults who followed the Mediterranean dietary pattern the closest over 4.4 years had a significantly reduced risk of developing depression (by 40% to 60%).

One key comment was: "Perhaps diet is the closest we've come to prevention in psychiatry." Some foods that are especially beneficial for the brain: seafood, greens, nuts, legumes (beans) and occasional dark chocolate. Use smaller amounts of meat (more as flavorings rather than just eating huge chunks of it) on top of a plant based diet. Also mentioned were the benefits of turmeric (because of the curcumin in it) and rosemary. And focus on improving the whole dietary pattern rather than just eating or not eating certain foods.

Note that BDNF is Brain-derived neurotrophic factor. This is a protein that acts on the brain, the nervous system, and it is very important for learning, memory, and higher thinking. So increasing BDNF levels is good. And remember, what's good for the brain is also good for the body and microbes - it's all intertwined. From Medscape:

Beans, Greens, and the Best Foods For the Brain

Dr Ramsey, in collaboration with the new International Society for Nutritional Psychiatry, is in the process of developing a standardized "brain food diet." "Food is a very effective and underutilized intervention in mental health," he started off. "We want to help our patients have more resilient brains by using whole foods...by helping get patients off of processed foods, off of white carbohydrates, and off of certain vegetable oils."

Though the field is in its infancy, food psychiatry is increasingly being embraced by clinicians and researchers, as a paper published earlier this year in the Lancet Psychiatry attests. "Although the determinants of mental health are complex," the authors wrote, "the emerging and compelling evidence for nutrition as a crucial factor in the high prevalence and incidence of mental disorders suggests that diet is as important to psychiatry as it is to cardiology, endocrinology, and gastroenterology." ..."The data are very promising that we can positively influence mental health through dietary interventions," commented Dr Ramsey.

"Hominid diets have changed drastically through millions of years of evolution.,,,But only in the past 100 years has our diet drastically switched from a whole foods diet to one that is more processed and high in refined carbohydrates; that includes more vegetable fats rather than meat fats; and preservatives, emulsifiers, and other additives, which appear to have contributed to a decline in our collective health.

Early humans evolved in the African Rift Valley, which is near a seacoast. It's possible that whatever evolutionary spark occurred that made us human occurred here, in part due to reliable access to seafoodoysters in particular—which glutted our brains with omega-3 fatty acids and cholesterol (our brains are composed of 60% fat). Oysters and other mollusks are also very high in nutrients, including B12, which is commonly deficient in people consuming vegan or vegetarian diets and is necessary for myelin and neurotransmitter function. 

A number of studies have linked the Mediterranean diet (high in fish oils, nuts, and grains and including maybe a little red wine) with advantageous effects on neurologic and mental health. Dr Deans cited recent work reporting that adults who followed the Mediterranean dietary pattern the closest over 4.4 years had a significantly reduced risk of developing depression (40%-60%)....When taken together, most of these dietary pattern studies, which have been conducted all over the world, consistently show that traditional, pre-processed diets are the healthiest, including for the brain. ..."Eat the rainbow," he says, given that bold, bright colors in nature tend to signify valuable vitamins and phytonutrients (the reds, purples, and greens in particular).

Seafood: Seafood is packed with brain-healthy omega-3 fatty acids. These healthy fats are also abundant in plants like chia and flax, but plant-based sources aren't as efficiently converted to docosahexaenoic acid (DHA), an important structural component of neuronal membranes. DHA also influences the expression of brain-derived neurotrophic factor (BDNF), which can benefit people who have mood and anxiety disorders. Bivalves like mussels, oysters, and clams are the top source of vitamin B12 as well as zinc: Six oysters (only about 10 calories each) provide 240% of our recommended daily B12 intake and 500% of our recommended zinc intake! Seafood is also a leading dietary source of vitamin D (we don't get it all from the sun) as well as iodine and chromium. Although many people worry about mercury in fish, Dr Ramsey provided an easy way around the concern: Eat small fish like sardines, anchovies, and herring, which typically don't accumulate toxic levels.

Leafy greens: A great base for a brain-food diet, leafy greens are a good source of fiber, folate (derived from the wordfoliage), magnesium, and vitamin K. Perhaps surprising, kale, mustard greens, and bok choy provide the most absorbable form of calcium on the planet, more so than milk. Greens also provide flavanols and carotenoids that have beneficial epigenetic influences (eg, including upping hepatic toxin processing). 

Nuts:... Nuts are packed with healthy monounsaturated fats. They help keep us full and also aid in absorbing fat-soluble nutrients. Nuts also provide fiber as well as minerals like manganese and selenium. A serving of 22 almonds (just 162 calories) contains 33% of our recommended vitamin E, plenty of protein, and minerals, including iron. One study from 2013 found that the Mediterranean diet augmented with nuts is associated with significantly higher BDNF levels in patients with depression.

Legumes: Dr Ramsey is pro-meat, but he acknowledges that many people are eating far too much and the wrong types of meat, and that nuts and legumes are a great alternative source of protein and nutrients...Some data suggest that vegan and vegetarian diets are associated with improved mood. But as previously mentioned, these dietary patterns can result in B12 deficiency, which has been associated with brain atrophy and developmental delay. Hence, supplementation is important in this population. Vegetarianism has also been linked with depression, anxiety, and eating disorders, as well as increased healthcare utilization and worse quality of life. These negative associations also could be due to the fact that it's harder to absorb nutrients like zinc, iron, and certain omega-3s from plants.

"The notion that the vegan diet is the healthiest diet on the planet is probably incorrect," said Dr Ramsey, before explaining that he just feels that we should approach meat in our diets differently....We want to help patients use beef and seafood more as flavorings on top of a plant-based diet." A modest amount of meat in the diet has its benefits, including nutrient availability: Hemoglobin-derived iron is up to 40% more absorbable than plant-based iron. Unlike most plants, meat provides all of the amino acids necessary for protein synthesis. Dr Ramsey emphasized the importance of seeking out leaner, grass-fed meats if one has the means.

The understanding of how microbiota contribute to our mental and medical well-being is rapidly advancing....One of the most powerful interventions to alter our microbiome is diet. Research shows that stressed mice experienced changes in the gastrointestinal microbiota, reflecting the gut-brain relationship. There are 260 million neurons connecting the gut and the brain; furthermore, many commensal gut bacteria make neurotransmitters and communicate with the brain via the vagus nerve....Although the science of probiotic therapies is relatively young, it's clear that these commensal organisms co-evolved with us and are adapted to our diet.

Finally, to close out the session, Dr Ramsey returned to the stage and asked, "So, can you eat to build a better brain? We think that you can if you focus on dietary patterns and not a single food here or there." He also reminded the audience to help their patients identify and increase their consumption of nutrient-dense foods and to "eat the rainbow,"..."I don't know of anything else that can potentially decrease the risk of depression in a population by 40%," he concluded. "Perhaps diet is the closest we've come to prevention in psychiatry."

...Evidence suggests that curcumin, an ingredient in turmeric, increases BDNF. Other research has found that populations that eat more curry have a decreased risk for dementia, while rosemary extract may help prevent cognitive impairment. "Many spices seem to have healing properties," Dr Ramsey commented.

Although the "Food and the Brain" session at the American Psychiatric Association annual meeting focused on what to eat in the interest of brain health, intermittent fasting might also be beneficial for the brain. In addition to helping maintain a healthy weight, fasting induces ketosis. Ketone metabolism has been shown to be beneficial for the brain and improve cognition in patients with mild cognitive impairment or Alzheimer disease. Keep in mind that fasting can come with risks for some people, particularly diabetics, and should be discussed with a healthcare provider.

Image result for plant foods Prostate cancer diagnosis is scary enough, but knowing that dietary changes can increase favorable odds is good. Once again a Mediterranean style diet  or "healthy diet"(whole grains, fruits, vegetables, seeds, nuts, legumes, olive oil, and fish) is beneficial, while a Western diet (highly processed foods, red meat, processed meat, and dairy) is linked to higher rates of death. This study was from the Harvard School of Public Health and followed male physicians for an average of 14 years after prostate cancer diagnosis. From Science Daily:

Western diet may increase risk of death after prostate cancer diagnosis

After a prostate cancer diagnosis, eating a diet higher in red and processed meat, high-fat dairy foods, and refined grains--known as a Western diet--may lead to a significantly higher risk of both prostate cancer-related mortality and overall mortality compared with eating a diet rich in vegetables, fruits, fish, whole grains, legumes, and healthy oils, according to a new study from Harvard T.H. Chan School of Public Health.

The study, which appears online June 1, 2015 in the journal Cancer Prevention Research, offers insight on how diet may help improve survivorship for the nearly three million men living with prostate cancer in the U.S."There is currently very little evidence to counsel men living with prostate cancer on how they can modify their lifestyle to improve survival. Our results suggest that a heart-healthy diet may benefit these men by specifically reducing their chances of dying of prostate cancer," said Jorge Chavarro, assistant professor of nutrition and epidemiology at the Harvard Chan School and senior author of the study.

Researchers examined health and diet data from 926 men participating in the Physicians' Health Study I and II who were diagnosed with prostate cancer. They followed the men for an average of 14 years after their diagnosis, grouping them into quartiles according to whether they followed a Western dietary pattern or a "prudent" (higher consumption of vegetables, fruits, fish, legumes, and whole grains) dietary pattern.

They found that men who ate mostly a Western diet (those in the highest quartile of the Western dietary pattern) had two-and-a-half times higher risk of prostate cancer-related death--and a 67% increased risk of death from any cause--than those in the lowest quartile. Men who ate mostly a "prudent" diet had a 36% lower risk of death from all causes.

photograph People are correctly raising the issue of whether the positive results (less diabetic nerve pain in type 2 diabetics) are due to the weight loss or to the vegan diet (which caused the quick weight loss)? I suspect it's the average 15 pound weight loss, which lowers inflammation and improves blood flow to the feet. And substituting whole plant-based foods (fruits, vegetables, whole grains, etc) for unhealthy highly processed foods has many health benefits, including controlling blood sugar. They all took B12 supplements because: B12 is found naturally only in animal products, so it's lacking in vegan diets; the diabetic medicine metformin lowers B12 levels; and a deficiency in vitamin B12 can actually cause nerve damage. Bottom line which applies to both diabetics and non-diabetics: some weight loss is good (if overweight), as is increasing beans, nuts, whole grains, vegetables, fruit and plant-based oils in the diet. From Medical Xpress:

Vegan diet might ease diabetic nerve pain

A vegan diet might help people with diabetes-related nerve damage shed weight and find some pain relief, a small pilot study suggestsVegan diets are free of all animal products, including eggs and dairy. Instead, people get their protein, fat and all other nutrients from foods such as beans, nuts, whole grains, vegetables, fruit and plant-based oils.

In the new study, researchers tested whether a vegan diet could help people with type 2 diabetes and painful nerve damage in their feet or hands. The investigators found that over 20 weeks, the 17 people they assigned to the diet lost an average of 15 pounds. At the same time, blood flow to their feet improved and their pain eased up.

But it's not clear that you have to go vegan to do that. "It's hard to say that it's this particular diet, itself," said Dr. Maria Pena, an endocrinologist and weight-management specialist at Lenox Hill Hospital in New York City. "The weight loss, by itself, can help with pain," said Pena, who was not involved in the study. Losing extra fat can decrease inflammation in the body, and improve a person's mobility—both of which could help ease diabetic nerve pain, she explained.

Plus, Pena said, better blood sugar control is key to reducing diabetic nerve pain—and the vegan dieters in this study did rein their sugar levels in. That shows the all-plant diet had benefits, according to Pena. But, she said, any diet that encourages weight loss and replaces processed foods with healthy "whole" foods might do the same.

About half of all people with diabetes eventually develop nerve damage because of chronically high blood sugar levels, according to the U.S. National Institutes of Health.The nerve damage—known as neuropathy—can occur anywhere, but most often affects the feet and legs. It can trigger sharp pain, burning sensations, tingling or sensitivity to even a light touch; it also makes people susceptible to serious foot problems, including ulcers and infections.

Cameron Wells, one of the researchers on the study, agreed that the finding doesn't prove that the vegan diet, per se, improved people's neuropathy. But the "hypothesis," she said, is that the diet worked by boosting people's sensitivity to the hormone insulin, which then brought down their blood sugar levels.

For the study, Wells and her colleagues recruited 34 adults with type 2 diabetes and painful neuropathy. They randomly assigned half to follow a vegan diet and take a vitamin B12 supplement; the rest took the supplement but stuck with their normal diets. The dieters were told to limit themselves to 20 to 30 grams of fat per day, and to load up on "low GI" foods, which are foods that do not cause a large surge in blood sugar.Breakfast might include oatmeal with raisins, Wells said, while dinner could be lentil stew, or a vegetable stir-fry with rice. After about five months, the vegan group had lost 15 pounds, on average, versus about 1 pound in the comparison group. They also reported bigger improvements on a standard pain-rating survey.

A big question for many adults is: how can one age well and live to a ripe old age? The author of the book The Blue Zones has dedicated a lot of time to studying communities throughout the world where there are a lot of centanarians and they age well (healthy). What are their secrets to aging well? The answer seems to be: while the diets vary, overall they have a lot of plant based whole foods, they have a lot of physical activity, are committed to their families, take time to de-stress, and they have social networks with healthy behaviors. From NPR:

Eating To Break 100: Longevity Diet Tips From The Blue Zones

Want to live to be 100? It's tempting to think that with enough omega-3s, kale and blueberries, you could eat your way there. But one of the key takeaways from a new book on how to eat and live like "the world's healthiest people" is that longevity is not just about food.

The people who live in the Blue Zones — five regions in Europe, Latin America, Asia and the U.S. researchers have identified as having the highest concentrations of centenarians in the world — move their bodies a lot. They have social circles that reinforce healthy behaviors. They take time to de-stress. They're part of communities, often religious ones. And they're committed to their families.

But what they put in their mouths, how much and when is worth a close look, too. And that's why Dan Buettner, a National Geographic explorer and author who struck out on a quest in 2000 to find the lifestyle secrets to longevity, has written a follow up to his original book on the subject. The new book, called The Blue Zones Solution, is aimed at Americans, and is mostly about eating.

Why should we pay attention to what the people in the relatively isolated Blue Zone communities eat? Because, as Buettner writes, their more traditional diets harken back to an era before we Americans were inundated with greasy fast food and sugar. And to qualify as a Blue Zone, these communities also have to be largely free of afflictions like heart disease, obesity, cancer and diabetes. So clearly they're doing something right.

But in a nutshell, Buettner in 2004 rounded up a bunch of anthropologists, demographers, epidemiologists and other researchers to travel around the world to study communities with surprisingly high percentages of centenarians. He and the scientists interviewed hundreds of people who'd made it to age 100 about how they lived, then did a lot of number crunching to figure out what they had in common.A year after that book was published, the team announced they'd narrowed it down to five places that met all their criteria. They gave them official Blue Zone status: Ikaria, Greece; Okinawa, Japan; Ogliastra Region, Sardinia; Loma Linda, Calif.; and Nicoya Peninsula, Costa Rica

In the new book, which was released April 7, Buettner distills the researchers' findings on what all the Blue Zones share when it comes to their diet. Here's a taste: - Stop eating when your stomach is 80 percent full to avoid weight gain. Eat the smallest meal of the day in the late afternoon or evening. Eat mostly plants, especially beans. And eat meat rarely, in small portions of 3 to 4 ounces. Blue Zoners eat portions this size just five times a month, on average. - Drink alcohol moderately and regularly, i.e. 1-2 glasses a day.

Ikaria, Greece You may remember this Blue Zone from Buettner's wonderful 2012 New York Times Magazine article entitled "The Island Where People Forget To Die." As we've reported, health researchers have long praised the Mediterranean diet for promoting brain and physical health and keeping chronic diseases at bay. 

"Their tradition of preparing the right foods, in the right way, I believe, has a lot to do with the island's longevity," writes Buettner. And "what set it apart from other places in the region was its emphasis on potatoes, goat's milk, honey, legumes (especially garbanzo beans, black-eyed peas, and lentils), wild greens, some fruit and relatively small amounts of fish."Ikaria has a few more "top longevity foods:" feta cheese, lemons and herbs like sage and marjoram that Ikarians use in their daily tea...The Ikarians do eat some goat meat, but not often.

Sardinia, Italy ...Buettner writes that the Sardinians explain their exceptional longevity with their assets such as "clean air," "locally produced wine," or because they "make love every Sunday." But when Buettner brought along a researcher to dig deeper, they found that pastoralism, or shepherding livestock from the mountains to the plains, was most highly correlated with reaching 100.

So what are those ancient Sardinian shepherds eating? You guessed it: goat's milk and sheep's cheese — some 15 pounds of cheese per year, on average. Also, a moderate amount of carbs to go with it, like flat bread, sourdough bread and barley. And to balance those two food groups out, Sardinian centenarians also eat plenty of fennel, fava beans, chickpeas, tomatoes, almonds, milk thistle tea and wine from Grenache grapes.

Loma Linda, CalifThere's a Blue Zone community in the U.S.? We were as shocked to learn this as you may be. Its members are Seventh-day Adventists who shun smoking, drinking and dancing and avoid TV, movies and other media distractions. They also follow a "biblical" diet focused on grains, fruits, nuts and vegetables, and drink only water. ...Another key insight? Pesco-vegetarians in the community, who ate a plant-based diet with up to one serving of fish a day, lived longer than vegan Adventists.Their top foods include avocados, salmon, nuts, beans, oatmeal, whole wheat bread and soy milk.

A distinct version of the Mediterranean diet is followed on the Blue Zone island of Ikaria, Greece. It emphasizes olive oil, vegetables, beans, fruit, moderate amounts of alcohol and low quantities of meat and dairy products.A distinct version of the Mediterranean diet is followed on the Blue Zone island of Ikaria, Greece. It emphasizes olive oil, vegetables, beans, fruit, moderate amounts of alcohol and low quantities of meat and dairy products.

My last post A Special Gut Microbe was on the very essential and beneficial microbe Faecalibacterium prausnitzii. It is one of the most abundant  bacteria in the gut of healthy individuals, but low or depleted levels are associated with inflammation and found in a number of diseases, including intestinal bowel diseases such as Crohn's disease. It is a butyrate producing bacteria (beneficial). F. prausnitzii is viewed as so essential that it has been called a "keystone species" in the gut. Now the question I've been asked is: how can one increase the numbers of this bacteria in the gut and where can one buy some to take as a probiotic? (Probiotics are live bacteria that are beneficial to health when consumed.)

The typical bacteria added to yogurts or sold as supplements are able to survive when exposed to air (oxygen). However, F. prausnitzii are "oxygen sensitive" and they die within minutes upon exposure to air. Researchers view this beneficial bacteria as a "probiotic of the future" and currently there is research going on to figure out ways it can be easily stored and be exposed to air a few hours and not die. So currently there is NO way to take a probiotic F. prausnitzii supplement. So what else can one do?

After reviewing the scientific literature, it seems that the current ways to get F. prausnitzii into the gut or increase its numbers are: fecal microbiota transplant or FMT (currently only done with desperately ill individuals), drastically restricting calories for one week by obese individuals increases beneficial bacteria, and making changes to the diet. For example, a high animal meat, high animal fat, high sugar, highly processed foods, and low fiber diet (the typical westernized diet) lowers F. prausnitzii numbers, while a high-fiber, low meat diet increases F. prausnitzii numbers.

Repeat: the number one thing a person can do to increase numbers of F. prausnitzii is to increase fiber in the diet. By the way, increasing dietary fiber increases butyrate, and butyrate is involved with colon health, is anti-inflammatory, and anti-cancer . See, it's all related. By high fiber is meant: whole grains, vegetables, fruits, nuts, seeds, and legumes. Eat a varied plant-based diet, which means lots of plant based foods. It seems that Michael Pollan's emphasis on "Eat real foods. Mostly plants. Not too much." is just right. And variety seems important - with different types of fiber feeding different bacteria. While F. prausnitzii may be an important beneficial bacteria in the gut, it is not the only beneficial one. So a food labeled "with added fiber" may not be the right fiber for bacteria, This is even true for enteral formula supplementation, for example one formula containing fiber used pea fiber and this did not feed the F. prausnitziiAssociation between Faecalibacterium prausnitzii and dietary fibre in colonic fermentation in healthy human subjects

In the first paragraph I mentioned that research has consistently shown F. prausnitzii depletion in adults sick with IBDs such as Crohn's disease. So it was interesting to find that one recent study found that even people sick with Crohn's disease showed significant improvement and remission (92% remission at 2 years) on a semi-vegetarian diet, namely a lacto-ovo-vegetarian diet (daily 32.4 g of dietary fiber in 2000 calories). High Amount of Dietary Fiber Not Harmful But Favorable for Crohn Disease This is totally opposite from the current prevailing medical view which currently encourages people with IBD to "rest the intestine" with a fiber-restricted diet.

Nice summary of cancer prevention advice. What it boils down to is that there is no magic bullet for cancer prevention (maybe the closest thing is to NOT smoke), but it's a lot of little things adding up (your lifestyle) that lowers the risk of cancer. From The Washington Post:

Looking for that fruit or vegetable that might prevent cancer?

Blueberries. Green tea. Tomatoes. And, oh, that cruciferous cauliflower. All make the lists of super foods that might help prevent cancer. Then there are the foods such as smoked meat and fried foods that supposedly might cause cancer. Such information is standard fare for TV doctors and Web sites, but most of us don’t know how to judge such claims. What sounds authoritative may not be. Only about half of the recommendations on two internationally syndicated TV medical talk shows were supported by scientific evidence, according to a recent study in the journal BMJ.

Of course, the blueberries we eat today are good for us. But nutrition’s role in cancer prevention is much more complex than a single dietary component: Evidence has mounted, for example, that lifestyle — diet, weight control and exercise — is vital in helping reduce risk. For now, experts endorse general dietary advice that is healthful for a variety of chronic diseases and conditions, rather than reductionist thinking that focuses on single foods or nutrients.

When you hear that a certain food helps prevent cancer, ask: Which cancer? “Cancer is multiple diseases,” said Marian Neuhouser, a nutritional epidemiologist at the Fred Hutchinson Cancer Research Center in Seattle. Whereas cardiovascular disease might be broken down into several types, including myocardial infarction, stroke and peripheral vascular disease, she said, “for cancer, it’s really over 100 different diseases.” “Cancer is a very complex, very challenging disease to study whether you’re looking at it on the cell level or the clinical level or the epidemiologic and preventive level,” Willett said.

Researchers caution about overreacting to a single study. New findings come out every week, but “we never take any one study to be the answer to anything,” said Nancy Potischman, a nutritional epidemiologist at the National Cancer Institute. Only if the same results come up in multiple studies across multiple populations, “then you might think that, yes, this food might be important,” she said.

Tobacco use remains the leading preventable cause of cancer incidence and death worldwide. After tobacco, the lifestyle trio of diet, weight control and exercise may be linked to one-third to two-thirds of cancers. “They’re inseparable,” Neuhouser said. “You can have a great diet and you can have a healthy weight, but if you’re extremely sedentary then there’s a risk.”And there’s a strong link between excess weight and several kinds of cancer, including the esophagus, breast (after menopause), endometrium, colon and rectum, kidney, pancreas, thyroid, gallbladder, according to the NCI. 

Evidence mounts about how lifestyle may affect risk of cancer. In the largest study of its kind, nearly half a million Americans were evaluated for adherence to American Cancer Society cancer prevention guidelines that include smoking avoidance; a healthful, consistent weight; physical activity; limiting alcohol; and a diet emphasizing plants.

Those who followed the guidelines most closely had lowered risk of developing cancer (10 percent for men, 19 percent for women) and dying from cancer (25 percent for men, 24 percent for women) compared with those whose habits were least in line with the guidelines. Most striking was the reduction of overall risk of dying: 26 percent for men, 33 percent for women during the 14-year study period.

Fourteen types of cancer seemed affected by lifestyle behavior, most particularly gallbladder, endometrial, liver and colorectal. For men and women, a healthful weight and physical activity were the top factors in reduced deaths overall. Albert Einstein College of Medicine Researchers published this analysis online in January in the American Journal of Clinical Nutrition, based on data from a National Institutes of Health/AARP study.

Another approach to cancer and nutrition considers dietary patterns. “What we eat on any one day is not going to change our cancer risk, but it’s the pattern over the long term.” Neuhouser said. Several diets that emphasized fruit, vegetables, whole grains and plants or plant-based proteins were analyzed against information collected over more than 12 years from nearly 64,000 post-menopausal women in the Women’s Health Initiative Observational Study. Consuming a high-quality diet was associated with lower death rates from chronic diseases including cancer, as reported last year in the American Journal of Epidemiology.

The bacteria, viruses and other organisms that live in and on humans seem to play a bigger role in health and disease than was previously understood, Freudenheim said. How the countless microbes in such areas as the gut and the mouth might contribute to or prevent cancers is one of the open questions in the new area of study of the microbiome, which refers to the many organisms in the body, 10 percent of which are human and 90 percent nonhuman.

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I think many will say: Oh no! Totally vegan is best for weight loss?? From Science Daily:

Vegan diet best for weight loss even with carbohydrate consumption, study finds

People shed more weight on an entirely plant based diet, even if carbohydrates are also included, a study has concluded. Other benefits of eating a vegan diet include decreased levels of saturated and unsaturated fat, lower BMIs, and improved macro nutrients.

The study, conducted by the university's Arnold School of Public Health and published in The International Journal of Applied and Basic Nutritional Sciences, compared the amount of weight lost by those on vegan diets to those on a mostly plant-based diet, and those eating an omnivorous diet with a mix of animal products and plant based foods. At the end of six months, individuals on the vegan diet lost more weight than the other two groups by an average of 4.3%, or 16.5 pounds.

The study followed participants who were randomly assigned to one of five diets on the dietary spectrum: vegan which excludes all animal products, semi-vegetarian with occasional meat intake; pesco-vegetarian which excludes all meat except seafood; vegetarian which excludes all meat and seafood but includes animal products, and omnivorous, which excludes no foods.

Participants followed their assigned dietary restrictions for six months, with all groups except the omnivorous participating in weekly group meetings. Those who stuck to the vegan diet showed the greatest weight loss at the two and six month marks.The lead author on this study, Gabrielle Turner-McGrievy notes that the diet consumed by vegan participants was high in carbohydrates that rate low on the glycemic index

The following is from a presentation from The American Association of Diabetes Educators Annual Meeting August 6-9, 2014 by M.Jardin and C.Kafity. But the coffee and tea statement is different from what I've read elsewhere, specifically that coffee is beneficial, is a source of soluble fiber, and may keep pathogenic bacteria in check. From Endocrinology Today:

Plant-based diet helps grow healthy microbiota, halt diabetes disease process

With research mounting on the onslaught the body’s microbiota take from human eating patterns and the environment, making choices to maintain inner ecosystem health is essential, according to presenters at the American Association of Diabetes Educators Annual Meeting. Choosing a plant-based diet is one way people can increase the diversity of bacteria in their biome, reduce inflammation and begin to reverse the diseases processes involved in obesity and diabetes — often in just a few days.

“We know obesity and diabetes have increased tremendously in the last 20 years and we know that our genes haven’t changed, so that can’t account for the change,” Meghan Jardine, MS, MBA, RD, LD, CDE, RDN, of Parkland Health and Hospital System, said during a presentation. “Many scientists believe the changes in our diet and physical activity can’t really account for the change either, that there’s something else at work here.”

Weighing at least two kilograms in all and accounting for more than 3 times the amount of the body’s human cells, gut bacteria is colonized after birth, stabilized by age 3 years but influenced by a number of external factors, Jardine explained. Areas of influence include nutrition and immune function, both priorities in treating obesity and diabetes.

“Microbiota releases enzymes that digest food so we can absorb nutrients, produces vitamins, combats opportunistic infections and works with the immune system,” Jardine said. “About 70% of our immune systems are in our gut.”

People who consume plant-based diets have “healthy” gut microbiota in terms of global parameters and functional and compositional features, Christina Kafity, RN, BSN,CHC... “Children and elderly individuals who consumed more plant carbohydrates versus the typical standard American diet had rapid, reproducible alterations of the gut microbiota for the better, and this happened within 24 hours to a week,” Kafity said.

Growing good bacteria depends on creating an environment in which they can thrive, Kafity explained, including choosing foods that contain certain fibers intact in plants and probiotics; among them are soluble, insoluble and functional fibers as well as psyllium and inulin.

Intake of cruciferous vegetables including Brussels sprouts, kale and cabbage can help boost healthy microbes and, further, provide glucosinolates to help to reduce inflammation, Kafity said. Yogurt, kefir and probiotics also promote the growth of good bacteria, Kafity noted, while some popular beverages may not be much help. “We’re considering that coffee and teas may actually sterilize the bacteria.”

From the December 11, 2013 National Geographic:

You Are What You Eat, All 100 Trillion Of You

By setting ten volunteers on either a vegetarian menu or a carnivorous one,Lawrence David from Duke University and Harvard University’s Peter Turnbaugh have shown that when our diet changes, our gut bacteria react very quickly. Within days, some species step into the limelight, while others fade into the background. They activate different genes, pull off different metabolic tricks, and secrete different substances. Our microbiome, it seems, can rapidly switch between plant-eating and meat-eating modes.

David’s team wanted to see what happens over days. If you flood your gut with different food, how long does it take for your microbiome to react?

They did this by recruiting ten volunteers who were willing to collect daily faecal samples. They each ate two different diets for five straight days —a plant-based one that was rich in grains, legumes, fruit and vegetables, and an animal-based one composed of meat, eggs and cheese.

In general, the animal diet led to more dramatic changes than the plant one. 

David and Turnbaugh’s team also found that the altered gut communities did different things. During the plant diet, they became better at breaking down carbohydrates; during the animal diet, protein digestion was their forte. On the meat-heavy days, they activated more genes for breaking down harmful chemicals found in charred meat, and for making vitamins.

And these changes happened very quickly. Some were obvious by day one. By day four, you could pick up a stool sample, list the active genes within it, and predict with total accuracy which diet the owners had been on.

Just two days after the volunteers stopped their diets, things were back to normal. The gut microbiome, it seems, is a fickle beast—easily changed, but not permanently so. The team also found that our food doesn’t just change the microbes that already exist in the gut—they also add some new ones. 

The point is that our gut microbiomes are more flexible than we previously thought. A recent study showed that most of the strains in our guts stay there for decades or more. But while the roster is clearly stable, their relative numbers fluctuate a lot, and food-borne newcomers can gain a foothold.