For years research on healthy eating has focused primarily on physical health and the link between diet, weight and chronic disease. But the emerging field of nutritional psychiatry studies how foods can make us feel.
“Many people think about food in terms of their waistlines, but it also impacts our mental health,” said Dr. Uma Naidoo, a Harvard psychiatrist and the director of nutritional and lifestyle psychiatry at Massachusetts General Hospital. “It’s a missing part of the conversation.”
The connection between the stomach and the brain is strong, and it starts in the womb. The gut and brain originate from the same cells in the embryo, says Dr. Naidoo. One of the main ways the brain and gut remain connected is through the vagus nerve, a two-way chemical messaging system that explains why stress can trigger feelings of anxiety in your mind and butterflies in your stomach.
Food can also influence the state of your microbiome, and some species of gut microbes have been linked to higher rates of depression. Even the brain chemical serotonin, which regulates mood, has a strong gut connection. Only 5 percent of your body’s serotonin is made in the brain; the rest is made, stored and active in the gut, said Dr. Naidoo.
Scientists do know that about 20 percent of everything we eat goes to the brain, said Dr. Drew Ramsey, a psychiatrist and assistant clinical professor at the Columbia University.
To help patients remember the best foods to eat to support brain health, Dr. Ramsey has devised a simple mantra: “Seafood, greens, nuts and beans — and a little dark chocolate.”
Dr. Ramsey calls leafy greens the foundation of a brain health diet because they’re cheap, versatile and have a high ratio of nutrients to calories. Kale is his personal favorite, but spinach, arugula, collards, beet greens and chard are also great sources of fiber, folate and vitamins C and A. If you’re not a fan of salads, add greens to soups, stews, stir fries and smoothies, or turn them into a pesto. He also recommends adding a small serving of seaweed (the “leafy green of the sea”) to your plate once a week as a source of iodine, fiber, zinc and additional phytonutrients.
Colorful fruits and vegetables
The more colorful your plate, the better the food is for your brain. Studies suggest that the compounds in brightly colored fruits and vegetables like red peppers, blueberries, broccoli and eggplant can affect inflammation, memory, sleep and mood. Reddish-purplish foods are “power players” in this category. And don’t forget avocados, which are high in healthy fats that enhance the absorption of phytonutrients from other vegetables.
Sardines, oysters, mussels, wild salmon and cod are sources of long-chain omega-3 fatty acids that are essential for brain health. Seafood is also a good source of vitamin B12, selenium, iron, zinc and protein. If you don’t eat fish, chia seeds, flax seeds and sea vegetables are also good sources of omega-3s.
Nuts, beans and seeds
Try to eat between a half and a full cup of beans, nuts and seeds a day, says Dr. Ramsey. Nuts and seeds, including cashews, almonds, walnuts and pumpkin seeds, are a great snack, but they can also be added to stir fry dishes and salads. Black and red beans, lentils and legumes can also be added to soups, salads and stews or enjoyed as a meal or a side dish. Nut butters count too.
Spices and herbs
Cooking with spices not only makes your food taste better, but studies suggest certain spices may lead to a better balance of gut microbes, reduce inflammation and even improve memory. Dr. Naidoo especially likes turmeric; studies suggest that its active ingredient, curcumin, may have benefits for attention and overall cognition. “Turmeric can be very powerful over time,” she said. Adding a pinch of black pepper makes curcumin 2,000 percent more bio-available to our brain and body,” she said. Other spices that may support brain health include cinnamon, rosemary, sage, saffron and ginger.
A recent study found that six servings a day of fermented foods can lower inflammation and improve the diversity of your gut microbiome. Fermented foods include yogurt; sauerkraut; kefir, a fermented milk beverage; kombucha, a fermented drink made with tea; and kimchi, a traditional Korean side dish of fermented cabbage and radish. Coconut kefir is a nondairy option. Other fermented foods include miso, cottage cheese, Gouda cheese and some types of apple cider vinegar. You can also drink probiotic-containing “gut shots,” which are small bottles of fermented beverages, usually about two ounces in size, sold in many grocery stores.
People who regularly eat dark chocolate have a 70 percent reduced risk of depression symptoms, according to a large government survey of nearly 14,000 adults. The same effect was not seen in those who ate a lot of milk chocolate. Dark chocolate is packed with flavonols, including epicatechin, but milk chocolate and popular candy bars are so processed they don’t have much epicatechin left in them.