Everyone knows instinctively that food impacts the brain. When you’re depressed, you reach for chocolate; when you’re tired, you crave coffee. “But it seems to be taking forever to turn it into science,” says Lisa Mosconi, associate director of the Alzheimer’s Prevention Clinic at New York-Presbyterian / Weill Cornell Medical Center and author of “Brain Food: The Surprising Science of Eating for Cognitive Power.”
Not anymore. A 2018 study Mosconi led suggests diet may be the No. 1 way to influence how your brain ages, compared to other lifestyle factors such as exercise and intellectual-enrichment activities. And starting in your 40s or 50s — when Alzheimer’s really begins — is also key, she says.
Fittingly, the brain is better protected than any other organ, thanks to the blood-brain barrier, akin to little gates that open and close when the brain needs a specific nutrient, such as vitamins B12 or C. If a nutrient is essential, the brain has a gate (or receptor) for it; nutrients that are unnecessary or harmful, including cholesterol, are denied access, Mosconi says. Historically, researchers have focused on specific nutrients when making dietary recommendations, but no longer. “It’s what you take in total content, because there are interactions between everything,” says James Galvin, a neurologist and founding director of Florida Atlantic University’s Comprehensive Center for Brain Health. “You can’t say, ‘I’m going to eat broccoli and everything will be fine.’ It doesn’t work like that.”
[See: 9 Foods That Can Keep Your Brain Sharp.]
So how can you eat to benefit your brain?
The simplest answer: Follow a diet that’s already been shown to have health benefits , like the Mediterranean diet (whose data were recently reanalyzed, though the findings remained the same). This plan is heavy on fruit, vegetables, fish, legumes and whole grains, and light on dairy, meat, poultry, saturated fat and processed foods, which are a cause of inflammation, and thus, tissue breakdown and reduced brain metabolism, hallmarks of cognitive decline. If the tissue damage is sustained enough, microglia cells — the brain’s housekeepers — become activated and can further harm the brain.
The Mediterranean diet serves up nutrients — polyunsaturated fats, all the B vitamins — that increase the survival of neurons in the lab and in animal studies, Galvin explains. These nutrients are not only building blocks for growth factors, which encourage new neural cell growth, but also help maintain cell membrane integrity and are involved in sugar and protein transport and gene expression. Two 2018 studies Mosconi was part of found that people who ate a standard Western diet, high in processed food, fast food, red meat and refined sugar but low in fiber, showed a decline in brain metabolism of about 3 percent per year while brain metabolism remained stable in the Mediterranean dieters. Western dieters also started the study with 15 percent more amyloid plaques — protein fragments associated with Alzheimer’s — than the Mediterranean-diet group. During the study, plaques in the Western dieters increased by about 2 percent yearly while the Mediterranean dieters showed no change in plaque buildup.
Another brain-friendly diet, called MIND, prescribes less cheese and fish than the Mediterranean diet and more poultry, berries and green leafy vegetables. A 2015 study found that MIND dieters who stuck with the plan for an average of 4.5 years were at 53 percent lower risk for Alzheimer’s. While the same study found that strict Mediterranean adherents were at 54 percent lower risk, people who only moderately followed MIND still saw a 35 percent lower risk. Loosely following Mediterranean eating habits conferred no risk reduction.
[See: The Best Diet for Your Personality.]
Mary Sano, director of the Alzheimer’s Disease Research Center at the Icahn School of Medicine at Mount Sinai, cautions that there isn’t yet enough research on either diet to fully convince her of specific brain benefits. But you’re unlikely to go wrong following a diet of unprocessed foods, she adds. Sano recommends keeping your weight in check versus attempting to eat for brain health. “There’s some evidence that obesity has a whole set of risk factors,” she says, “including potentially a cognitive one.”
Before overhauling your eating plan, Rudolph Tanzi, a Harvard Medical School neurology professor and co-author of “The Healing Self” and “Super Genes,” recommends first eating more fiber. The guideline is 14 grams per 1,000 calories, or roughly 25 grams per day for women and 38 per day for men. Fiber feeds the trillions of bacteria in your gut, and the gut microbiome controls the blood-brain barrier and profoundly affects the amount of those dementia-causing plaques. (The poor-quality gut microbiome in people consuming a Western diet also has been linked to obesity, coronary vascular disease, strokes, cancer and more.) How to get more fiber? Add whole grains, whole fruits and vegetables, and beans. Only after upping your fiber intake should you worry about consuming probiotics, Tanzi says. Probiotics add bacteria to the gut, but the new bacteria won’t flourish without fiber. “You have to clean up the neighborhood first,” says Tanzi, an author of several studies exploring how manipulating the gut microbiome impacts the brain. (He was also part of a team that figured out how to create mini-brains in petri dishes — small balls of translucent jelly full of firing human neurons — in which Alzheimer’s can be replicated so drugs can be studied quickly and cheaply.) Look for a probiotic with bacteroidetes, actinobacteria and proteobacteria, he says.
Tanzi also suggests eating prebiotics — nondigestible carbohydrates that act as fertilizer for the gut bacteria. Good sources include Jerusalem artichokes, garlic, chicory, onions, asparagus, bananas, cabbage and leeks. Prebiotics can come in supplement form — many probiotics include them — but Mosconi cautions that supplements don’t work as well as food. “There are so many nuances of nature you can’t replicate,” she says.
[See: 13 Best Fish: High in Omega 3s — and Environmentally Friendly.]
Another simple way to support your brain health, no matter what you eat: Drink more water — unfiltered tap, if safe and potable, or spring, both of which have necessary minerals and electrolytes. Many water filters remove key nutrients along with toxins and chemicals. (Purified water, distilled water, seltzer and club soda are fluids with no nutrients, Mosconi says.) Most people are walking around dehydrated, Mosconi explains. But the brain is 80 percent water and highly sensitive to dehydration, which can cause brain fog, fatigue and confusion. Eight glasses a day is a good benchmark, although everyone’s needs are different. If you drink purified water, she advises taking mineral supplements to replace the missing — and vital — electrolytes.
It’s never too late to start making changes, no matter how good or bad you think your genetic luck is. Gene expression can be influenced by myriad lifestyle factors, and what you eat is a powerful lever for switching hundreds of thousands of genes on and off. And that switch can be flipped fairly quickly, Tanzi says. It takes roughly 60 to 70 days, based on studies of mice. So what are you waiting for?
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Food for Thought: Diet May Be the Top Way to Influence How Your Brain Ages originally appeared on usnews.com
