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Trans fats are commonly used in processed foods to improve taste, texture, and shelf life. Artificial trans fats are found in partially hydrogenated oils and in other ingredients, such as refined oils, emulsifiers, flavors and colors. Even those processed foods that say zero trans fats may contain trans fats - due to a loophole in labeling laws (if it has less than .5 grams per serving, then it can be rounded down to zero - thus allowing the incorrect claim of zero trans fats). Eating a variety of processed foods, each containing a little trans fats, easily adds up to eating a significant amount daily.Trans fats in the diet have long been linked to cardiovascular disease, artherosclerosis, obesity, oxidative stress, and inflammation, but now research finds that it is linked to a poorer memory in middle-aged men under the age of 45. From Science Daily:

Dietary trans fat linked to worse memory

Higher consumption of dietary trans fatty acids (dTFA), commonly used in processed foods to improve taste, texture and durability, has been linked to worsened memory function in men 45 years old and younger, according to a study.

Researchers evaluated data from 1,018 men and women who were asked to complete a dietary survey and memory test involving word recall. On average, men aged 45 and younger recalled 86 words; however, for each additional gram of trans fats consumed daily, performance dropped by 0.76 words. This translates to an expected 12 fewer words recalled by young men with dTFA intake levels matching the highest observed in the study, compared to otherwise similar men consuming no trans fats.

After adjusting for age, exercise, education, ethnicity and mood, the link between higher dTFA and poorer memory was maintained in men 45 and younger.The study focused predominantly on men because of a small number of women in this age group. However, including women in the analysis did not change the finding, said Golomb. An association of dTFA to word memory was not observed in older populations. Golomb said this is likely due to dietary effects showing more clearly in younger adults. Insults and injuries to the brain accrue with age and add variability to memory scores that can swamp ability to detect diet effects.

Trans fatty acids have been linked to negative effects on lipid profiles, metabolic function, insulin resistance, inflammation and cardiac and general health. In 2013, the United States Food and Drug Administration issued a preliminary determination that trans fats were no longer generally recognized as safe. According to the Centers for Disease Control, reducing dTFA consumption could prevent 10,000 to 20,000 heart attacks and 3,000 to 7,000 coronary heart disease deaths per year in the U.S.

Beware of big soda companies bearing gifts to scientists and their misleading messages to consumers. This time it is Coca-Cola that is trying to influence the research by funding scientists who shift blame for obesity to lack of exercise.There is a large body of evidence finding that what you eat is very important for health and weight control, and this does not mean a diet filled with highly processed foods, including soda.

Yes, exercise is important, but the overall diet is even more important. And we know that soda is not a beneficial food for the beneficial microbes within us (Feeding Your Gut Microbes). Coca Cola's sales of soda are really slipping and this Global Energy Balance Network is a major effort on their part to try to boost sales of sugary drinks. From NY Times:

Coca-Cola Funds Scientists Who Shift Blame for Obesity Away From Bad Diets

Coca-Cola, the world’s largest producer of sugary beverages, is backing a new “science-based” solution to the obesity crisis: To maintain a healthy weight, get more exercise and worry less about cutting calories.The beverage giant has teamed up with influential scientists who are advancing this message in medical journals, at conferences and through social media. To help the scientists get the word out, Coke has provided financial and logistical support to a new nonprofit organization called the Global Energy Balance Network, which promotes the argument that weight-conscious Americans are overly fixated on how much they eat and drink while not paying enough attention to exercise.  ...continue reading "Ignore Big Soda’s Message"

Another study finds health benefits to eating a Mediterranean based diet (here combined with the DASH diet) - the MIND diet. The researchers found that the older adults who followed the diet best were about 7.5 years younger cognitively than those who followed it least, thus suggesting that it may slow the cognitive decline of aging. Earlier research had suggested that it may reduce a person's risk in developing Alzheimer's disease. Foods to eat: fruits, vegetables, berries, whole grains, legumes (beans), nuts, fish, a little wine, and some chicken. Foods to limit on this diet: butter, red meat, margarine, sweets and pastries, whole fat cheese, and fried or fast food. From Medical Xpress:

Eating away at cognitive decline: MIND diet may slow brain from aging by 7.5 years

While cognitive abilities naturally diminish as part of the normal aging process, it may be possible to take a bite out of this expected decline. Eating a group of specific foods known as the MIND diet may slow cognitive decline among aging adults, even when the person is not at risk of developing Alzheimer's disease, according to researchers at Rush University Medical Center. This finding is in addition to a previous study by the research team that found that the MIND diet may reduce a person's risk in developing Alzheimer's disease.

The recent study shows that older adults who followed the MIND diet more rigorously showed an equivalent of being 7.5 years younger cognitively than those who followed the diet least. The results of the study recently were published online in the journal Alzheimer's & Dementia: The Journal of the Alzheimer's Association.

The National Institute of Aging funded study evaluated cognitive change over a period of 4.7 years among 960 older adults who were free of dementia on enrollment. Averaging 81.4 years in age....residents of more than 40 retirement communities and senior public housing units in the Chicago area. .... Martha Clare Morris, ScD, a nutritional epidemiologist, and colleagues developed the diet, whose full name is the Mediterranean-DASH Diet Intervention for Neurodegenerative Delay. As the name suggests, the MIND diet is a hybrid of the Mediterranean and DASH (Dietary Approaches to Stop Hypertension) diets. Both diets have been found to reduce the risk of cardiovascular conditions, like hypertension, heart attack and stroke.

"Everyone experiences decline with aging; and Alzheimer's disease is now the sixth leading cause of death in the U.S., which accounts for 60 to 80 percent of dementia cases. Therefore, prevention of cognitive decline, the defining feature of dementia, is now more important than ever," Morris says.

The MIND diet has 15 dietary components, including 10 "brain-healthy food groups" and five unhealthy groups - red meat, butter and stick margarine, cheese, pastries and sweets, and fried or fast food. To adhere to and benefit from the MIND diet, a person would need to eat at least three servings of whole grains, a green leafy vegetable and one other vegetable every day—along with a glass of wine—snack most days on nuts, have beans every other day or so, eat poultry and berries at least twice a week and fish at least once a week. In addition, the study found that to have a real shot at avoiding the devastating effects of cognitive decline, he or she must limit intake of the designated unhealthy foods, especially butter (less than 1 tablespoon a day), sweets and pastries, whole fat cheese, and fried or fast food (less than a serving a week for any of the three).

Berries are the only fruit specifically to be included in the MIND diet. "Blueberries are one of the more potent foods in terms of protecting the brain," Morris says, and strawberries also have performed well in past studies of the effect of food on cognitive function.

An observational study of older adults found that the Mediterranean diet may help preserve the connections between neurons in the brain, by preserving the microstructure in the white matter of the brain. This appeared to have a strong cognitive benefit - equal up to 10 years of delayed cognitive aging in those who adhered to the Mediterranean diet most closely. So if you haven't started already, try eating what the Mediterranean diet stresses: fruits, vegetables, whole grains, seeds, nuts, legumes, olive oil, some fish, and some wine. And cut back on highly processed foods, meat, and high fat foods. It's not one or two foods, but overall diet that is important. From Medscape:

Mediterranean Diet May Preserve Brain Structural Connectivity

The Mediterranean diet may help preserve structural connectivity in the brain in older adults, results of a French study hint. Greater adherence to the Mediterranean diet was associated with preserved microstructure in extensive areas of the white matter up to a decade later, the study team found. And this appeared to be related to strong cognitive benefit, equal to up to 10 years of delayed cognitive aging for those with the greatest adherence, they say....The study was published online July 16 in Alzheimer's & Dementia. The Mediterranean diet has been associated with a lower risk for Alzheimer's disease, but the underlying mechanisms have been unclear.

The new findings are based on 146 nondemented older adults in the Bordeaux Three-City study, a prospective cohort initiated in 1999-2000 to study vascular risk factors for dementia. Participants provided information on their diet in 2001-2002 (at a mean age of 73 years), underwent brain MRI an average of 9 years later (including diffusion tensor imaging)...On the basis of dietary assessment, 26% of participants had a low Mediterranean diet (MedDi) score of 0 to 3, indicating poor adherence to the diet; 47% had medium scores (4 or 5); and 27% had higher scores (6 to 8) representing the best adherence to the diet.

In adjusted analysis, there was no significant association between the MedDi score and grey matter or white matter volume. However, there was a strong association between the MedDi and diffusion tensor imaging patterns, suggesting that higher MeDi adherence was associated with a "general pattern of preserved WM [white matter] microstructure in multiple bundles," the researchers say. And preserved white matter microstructure with higher adherence to the MedDi "appeared to delay cognitive aging by up to 10 years."

"Our results suggest that the Mediterranean diet helps preserve the connections between neurons, which appear to be damaged with aging, vascular brain diseases and neurodegenerative diseases such as Alzheimer's dementia," Dr Samieri told Medscape Medical News. "In addition, the regions which appeared preserved with greater adherence to the Mediterranean diet were extended and were not specific to a particular disease, suggesting that the Mediterranean diet may have the potential to prevent not only stroke (as previously demonstrated with the PREDIMED [Prevención con Dieta Mediterránea] trial) but also multiple age-related brain pathologies," she added.

The added finding that none of the individual components of the Mediterranean diet was strongly associated with imaging results "supports our hypothesis that overall diet quality may be more important to preserve brain structure than any single food," they write.

For many years it was thought that yo-yo dieting resulted in higher cancer risk. So the findings of this study are a relief. Researchers looked at weight cycling (yo-yo dieting) and incidence for all cancer and 15 individual cancers among more than 132,000 participants during 17 years of study and found NO association with overall risk of cancer or any individual cancer. So feel free to diet and lose weight for the health benefits. From Science Daily:

Yo-yo dieting not associated with increased cancer risk

The first comprehensive study of its kind finds weight cycling, repeated cycles of intentional weight loss followed by regain, was not associated with overall risk of cancer in men or women. The study by American Cancer Society investigators is the largest to date to investigate weight cycling with cancer risk....Weight cycling was also not associated with any individual cancer investigated. The authors of the study say people trying to lose weight should be encouraged to do so even though they may regain it.

With almost half of American adults reporting they are trying to lose weight, and with most weight loss not maintained, weight cycling is very common. Previous studies in animals and humans had suggested that weight cycling may affect biological processes that could lead to cancer, such as increased T-cell accumulation, enhanced inflammatory responses in adipose tissue, and lowered natural killer cell cytotoxicity. However, many of these findings have not been replicated, and at least two previous studies showed no associations between weight cycling and cancer.

For the latest study, researchers led by Victoria Stevens, PhD, American Cancer Society Strategic Director, Laboratory Services, examined weight cycling and cancer among more than 132,000 men and women enrolled in the Cancer Prevention Study II Nutrition Cohort. Begun in 1992/1993, the Nutrition Cohort gathered detailed dietary information from men and women ages 50 to 74 participating in the Society's larger Cancer Prevention Study II, to explore nutrition's effect on and cancer incidence and mortality. Investigators looked at weight cycling and incidence for all cancer and 15 individual cancers. More than 25,000 participants developed cancer during 17 years of study.

One study points out the difficulty of weight loss in overweight adults, because so few actually are able to get down to a normal weight or even lose a mere 5% of body weight (for example. 10 pounds for a 200 pound person or 15 pounds for a 300 pound person). The annual chance of an obese person attaining normal body weight is only 1 in 210 for men and 1 in 124 for women,and the annual chance of obese patients achieving five per cent weight loss was 1 in 12 for men and 1 in 10 for women.  The second study highlights how well weight loss treats "fatty liver" (which is a problem in middle-aged overweight people). Fatty liver or nonalcoholic steatohepatitis (NASH), which affects 2 to 5 percent of Americans, can be severe and can lead to cirrhosis, in which the liver is permanently damaged and scarred and no longer able to work properly.

After reading scientific studies nonstop for the last few years, it seems that the best, easiest way to lose weight is to have lifestyle changes rather than focusing just on a "weight-loss diet": increase activity levels (yes, walking counts) and switch to a more plant based diet or Mediterranean diet (lots of fruits, vegetables, whole grains, legumes, seeds, nuts, olive oil, some fish each week) and decrease the amount of typical Western style diet (highly processed foods. lots of meat and coldcuts, lots of fat, fast foods, soda). Try to only eat within 12 hours each day (for example, 8am to 8pm) and don't eat the other 12 hours. And of course eat fewer calories (it should be easier  to do if you substitute fruits and vegetables for high calorie processed foods such as ice cream, french fries, and sweets). And yes, of course it's really hard to lose weight, but the health benefits of weight loss are enormous. From Medical Xpress:

Low chance of recovering normal body weight highlights need for obesity prevention

The chance of an obese person attaining normal body weight is 1 in 210 for men and 1 in 124 for women, increasing to 1 in 1,290 for men and 1 in 677 for women with severe obesity, according to a study of UK health records led by King's College London. The findings, published in the American Journal of Public Health, suggest that current weight management programmes focused on dieting and exercise are not effective in tackling obesity at population level.The research, funded by the National Institute for Health Research (NIHR), tracked the weight of 278,982 participants (129,194 men and 149,788) women using electronic health records from 2004 to 2014.

The annual chance of obese patients achieving five per cent weight loss was 1 in 12 for men and 1 in 10 for women. For those people who achieved five per cent weight loss, 53 per cent regained this weight within two years and 78 percent had regained the weight within five years.

Overall, only 1,283 men and 2,245 women with a BMI of 30-35 reached their normal body weight, equivalent to an annual probability of 1 in 210 for men and 1 in 124 for women; for those with a BMI above 40, the odds increased to 1 in 1,290 for men and 1 in 677 for women with severe obesity. Weight cycling, with both increases and decreases in body weight, was also observed in more than a third of patients. The study concludes that current obesity treatments are failing to achieve sustained weight loss for the majority of obese patients.

Dr Alison Fildes, first author from the Division of Health and Social Care Research at King's College London (and now based at UCL), said: 'Losing 5 to 10 per cent of your body weight has been shown to have meaningful health benefits and is often recommended as a weight loss target..... More importantly, priority needs to be placed on preventing weight gain in the first place.'

From Medical Xpress:  Weight loss for a healthy liver

Weight loss through both lifestyle modification and bariatric surgery can significantly reduce features of nonalcoholic steatohepatitis (NASH), a disease characterized by fat in the liver, according to two new studies published in Gastroenterology..."we most commonly see this condition in patients who are middle-aged and overweight or obese," said Giulio Marchesini, MD, from University of Bologna, Italy, and lead author of an editorial summarizing these two studies. "These two large prospective cohort studies strengthen the evidence that, no matter how you lose weight, weight loss improves liver health. Both bariatric surgery for morbidly obese patients or lifestyle modifications are viable options."

Lifestyle modifications: Eduardo Vilar-Gomez and colleagues from Cuba report in Gastroenterology that a weight reduction of 10 percent or more, induced by a comprehensive lifestyle program, is necessary to bring about NASH resolution and reverse scarring of the liver in overweight and obese patients. To a lesser degree, modest weight loss (7 to 10 percent) reduced disease severity in certain subsets of patients, including male patients and those without diabetes. Conversely, 93 percent of the patients with little or no weight reduction (less than 5 percent) experienced worsening of liver scarring....While promising, less than 50 percent of patients achieved the necessary weight loss goal of 7 to 10 percent, providing a stark reminder of the sustainability of weight loss interventions.

Bariatric surgery: For appropriate morbidly obese patients with NASH who have previously failed to lose weight through lifestyle modifications, bariatric surgery may be considered. In the second Gastroenterology study, Guillaume Lassailly and colleagues from France report that, one year after bariatric surgery, NASH had disappeared from 85 percent of patients and reduced the pathologic features of the disease after 1 year of follow-up. NASH disappeared from a higher proportion of patients with mild NASH before surgery (94 percent) than severe NASH (70 percent). More studies are needed to determine the long-term effects of bariatric surgeryin morbidly or severely obese patients with NASH.

I've been reading and thinking about "natural flavors" ever since my earlier posts about food additives (April 20, 2015, August 19, 2014). What exactly are natural flavors and how are they different from artificial flavors?  And why are they even found in organic foods? The more I read, the more I want to avoid them , but it seems to be really, really hard to do so because they seem to be everywhere, even in what we think of as basic foods (e.g., butter). Bottom line: both are chemicals concocted in labs and manufactured in factories. Read labels and try to eat as many unprocessed foods as possible to avoid them.We know very little about many of them, and if they have health effects. Note that the term "natural flavors" may include many chemicals in the "flavor mixtures" (incidental additives) that don't have to be listed on the labels. Currently there are more than 2700 natural flavors being used in the USA. The following are excerpts from articles and a book published in 2015.

From CNN:   What are natural flavors, really?

Look at the food label of almost any packaged good you consume and odds are you'll spot the term "natural flavors." But have you ever wondered what this mysterious additive actually contains? The answer isn't as clear as you might think.Though natural flavors may sound better than their presumably chemical-laden alternative — artificial flavors — it turns out they are not actually all that different.

In the Environmental Working Group's Food Scores database of over 80,000 foods, "natural flavor" is the fourth most common ingredient listed on labels. The only ingredients that outrank it: salt, water and sugar. Yet, natural flavoring isn't nearly as simple as these three pantry staples."Natural and artificial flavors play an interesting role in food. They're essentially providing the taste and often they're added to make the food more appealing, or to potentially replace something that's lost through processing, storage or in some cases even from pasteurizing," says David Andrews, senior scientist at the Environmental Working Group. One place you'll often spot natural or artificial flavor is in orange juice; manufacturers will add faux flavor to juice after it's packaged in the plant, to ensure uniformity.

"The differentiation is really down to the origin of those molecules, whether synthetically processed in a lab or purified in a lab but from a natural source," Andrews says. Here's where it gets even muddier: Added flavoring, both natural and artificial, could contain anywhere from 50 to 100 ingredients. And all of the extra ingredients in flavors often aren't as innocent as you'd hope they would be."The mixture will often have some solvent and preservatives — and that makes up 80 to 90 percent of the volume [of the flavoring]. In the end product, it's a small amount, but it still has artificial ingredients," Andrews says.  ...continue reading "What’s In the “Natural” Flavors In Our Foods?"

There has been much discussion recently about breastfeeding - why is it so important? Is it really better than formula? The answer is: YES, breastfeeding is the BEST food for the baby, and for a number of reasons. Not only is it nature's perfect food for the baby, but it also helps the development of the baby's microbiome or microbiota (the community of microbes that live within and on humans).

Specifically, breast milk transmits about 700 species of bacteria to the baby - bacteria that are important in developing the baby's microbiota, bacteria that are important for the baby's development and health in many ways (including the immune system). No formula does that. Not even close.

There is obviously much we don't know or understand yet, but finding 700 species in breast milk is a big deal. The most variety was in colostrum (the first milk), but even after 6 months (mature milk) they found hundreds of species of bacteria. What was also interesting was that the bacteria species in the breast milk varied whether the baby was born by vaginal birth, unplanned cesarean, or planned cesarean (this last had a somewhat different bacterial community which persisted through the 6 months of the study).

By the way, in the original study, the authors made a point of saying that the 700 bacteria species are NOT bacterial contaminants, but meant to be there! (for those who want to sterilize and pasteurize everything because they think that all bacteria are bad).

This study is from 2013, but well worth reading. From Science Daily: Breast milk contains more than 700 species of bacteria, Spanish researchers find

Researchers have traced the bacterial microbiota map in breast milk and identified the species of microbes taken from breast milk by infants. The study has revealed a larger microbial diversity than originally thought: more than 700 species. The breast milk received from the mother is one of the factors determining how the bacterial flora will develop in the newborn baby.

A group of Spanish scientists have now used a technique based on massive DNA sequencing to identify the set of bacteria contained within breast milk called microbiome.  Colostrum is the first secretion of the mammary glands after giving birth. In some of the samples taken of this liquid, more than 700 species of these microorganisms were found, which is more than originally expected by experts.

"This is one of the first studies to document such diversity using the pyrosequencing technique (a large scale DNA sequencing determination technique) on colostrum samples on the one hand, and breast milk on the other, the latter being collected after one and six months of breastfeeding," explain the coauthors, María Carmen Collado, researcher at the Institute of Agrochemistry and Food Technology (IATA-CSIC) and Alex Mira, researcher at the Higher Public Health Research Centre (CSISP-GVA).

The most common bacterial genera in the colostrum samples were Weissella, Leuconostoc, Staphylococcus, Streptococcus and Lactococcus. In the fluid developed between the first and sixth month of breastfeeding, bacteria typical of the oral cavity were observed, such as Veillonella, Leptotrichia and Prevotella....The study also reveals that the milk of overweight mothers or those who put on more weight than recommended during pregnancy contains a lesser diversity of species.

The type of labour also affects the microbiome within the breast milk: that of mothers who underwent a planned caesarean is different and not as rich in microorganisms as that of mothers who had a vaginal birth. However, when the caesarean is unplanned (intrapartum), milk composition is very similar to that of mothers who have a vaginal birth.

These results suggest that the hormonal state of the mother at the time of labour also plays a role: "The lack of signals of physiological stress, as well as hormonal signals specific to labour, could influence the microbial composition and diversity of breast milk," state the authors.

And yes, what you eat while breastfeeding has an effect on the breast milk. From Science Daily:  Carotenoid levels in breast milk vary by country, diet

A Purdue University-led analysis of breast milk concludes that levels of health-promoting compounds known as carotenoids differ by country, with the U.S. lagging behind China and Mexico, a reflection of regional dietary habits. Carotenoids are plant pigments that potentially play functional roles in human development and are key sources of vitamin A, an essential component of eye health and the immune system.

The carotenoid content of a woman's breast milk is determined by her consumption of fruits and vegetables such as squash, citrus, sweet potatoes and dark, leafy greens.

Eating green leafy vegetables and other brightly colored fruits and vegetables containing vitamin K, lutein, folate and beta-carotene were linked to keeping the brain healthy in older adults and slowing cognitive decline. Researchers found that older people who ate one to two servings per day had the cognitive ability of a person 11 years younger than those who consumed none. From Science Daily:

Eating green leafy vegetables keeps mental abilities sharp

Something as easy as adding more spinach, kale, collards and mustard greens to your diet could help slow cognitive decline, according to new research. The study also examined the nutrients responsible for the effect, linking vitamin K consumption to slower cognitive decline for the first time...."Since declining cognitive ability is central to Alzheimer's disease and dementias, increasing consumption of green leafy vegetables could offer a very simple, affordable and non-invasive way of potentially protecting your brain from Alzheimer's disease and dementia."

The researchers tracked the diets and cognitive abilities of more than 950 older adults for an average of five years and saw a significant decrease in the rate of cognitive decline for study participants who consumed greater amounts of green leafy vegetables. People who ate one to two servings per day had the cognitive ability of a person 11 years younger than those who consumed none. When the researchers examined individual nutrients linked with slowing cognitive decline, they found that vitamin K, lutein, folate and beta-carotene were most likely helping to keep the brain healthy.

To conduct the study, Morris' research team gathered data from 954 participants from the Memory and Aging Project, which aims to identify factors associated with the maintenance of cognitive health. The participants, whose age averaged 81, reported their daily food and beverage intake by answering a detailed 144-item questionnaire at the beginning of the study.... They followed participants for 2 to 10 years, assessing cognition annually with a comprehensive battery of 19 tests and adjusted for age, sex, education, smoking, genetic risk for Alzheimer's disease and participation in physical activities when estimating the effects of diet on cognitive decline.

"With baby boomers approaching old age, there is huge public demand for lifestyle behaviors that can ward off loss of memory and other cognitive abilities with age," said Morris. "Our study provides evidence that eating green leafy vegetables and other foods rich in vitamin K, lutein and beta-carotene can help to keep the brain healthy to preserve functioning." In addition to green leafy vegetables, other good sources of vitamin K, lutein, folate and beta-carotene include brightly colored fruits and vegetables.

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.