We already know that what we eat affects our bodies. Now a growing body of research suggests our food choices can also affect our minds.
The emerging field of nutritional psychiatry focuses on how eating certain foods may improve our mental health. Some research suggests that a variety of foods can help boost mood, improve cognition and even reduce the symptoms of depression and anxiety.
“An anti-anxiety diet can be a very powerful tool in improving our mental well-being,” said Uma Naidoo, a nutritional psychiatrist and the director of nutritional and lifestyle psychiatry at Massachusetts General Hospital. “It’s one of the many ways that we can help calm the mind.”
In her new book, “Calm Your Mind With Food: A Revolutionary Guide to Controlling Your Anxiety,” Naidoo explores the gut-brain connection. She said sometimes her patients find it difficult to believe that the gut – so distant in the body from the brain – could play a role in their mental health. But the gut and the brain are in constant conversation about digestion, appetite – and even your mood.
Scientists have long known of this strong connection, and some even refer to the gut as “the second brain,” Naidoo said. The vagus nerve, which starts in the brain and extends through the abdomen and intestines, helps explain why we often experience feelings of anxiety in the stomach. Another link between the gut and the brain is serotonin, an important neurotransmitter that affects mood and is mostly produced in the intestines.
More recently, the gut-brain axis, which is the communication network between the central nervous system and our gut microbes, has become a focal point for researchers studying the link between mental health and the microbiome. An imbalance in our gut microbes has been associated with anxiety and depression.
The foods we eat can have a profound effect on our microbiome, and Naidoo believes that by choosing the right foods – and reducing the detrimental ones – we can improve our mental health. The basics aren’t surprising. Naidoo recommends eating a diet high in whole foods – fruits, vegetables, legumes and unprocessed grains. She advises people to avoid refined carbohydrates, such as refined wheat flour; foods high in added sugars and those made with artificial sweeteners; and the unhealthy fats commonly found in packaged snacks and deep-fried foods.
She also recommends an anti-anxiety diet – eating specific foods to give your mental health a boost and calm your mind. If someone is already on treatment for anxiety, this is intended to be used as a complementary strategy to combat anxiety, Naidoo said.
We spoke to Naidoo about some of the foods that make up the diet. Here are seven of them.
1. Extra dark chocolate
Eat a couple of small squares of extra dark chocolate every other day, Naidoo recommends. Pair it with citrus fruit such as clementine or orange slices for an extra boost. Extra dark chocolate is rich in iron and polyphenols – plant compounds linked to several health benefits. Studies have found an association between iron deficiency and anxiety, while cocoa has been shown to boost mood. Citrus fruits have vitamin C, which has been shown to help with iron absorption.
Look for natural chocolate that is 75% cacao or more. “This is not a candy bar,” Naidoo said. The added sugar in milk chocolate outweighs the benefits, she added.
2. Leafy greens
Leafy greens are packed with fiber, folate, iron and other micronutrients, Naidoo said, as well as lutein, an antioxidant which research has shown can reduce depression in mice. Naidoo recommends adding different colored leafy greens to salads. You can also steam spinach and stir fry leafy greens or add them to a soup.
Broccoli and other cruciferous vegetables, including cauliflower, Brussels sprouts and cabbage, are an essential part of the anti-anxiety diet, Naidoo said. They are rich in sulforaphane, a powerful phytochemical that she said “helps with the inflammation that we’re trying to fend off in the gut.”
Chopping broccoli before cooking helps maintain its levels of sulforaphane, she said. Let it sit for 30 to 60 minutes after chopping and then place it in the fridge. If you’re making broccoli for dinner, she said, “cut it and clean it in the morning and leave it in a clean baggie in the fridge until you’re using it.”
Avocados are rich in fiber, potassium, vitamin E and magnesium. Low intake of magnesium has been linked to depression, and there is some research indicating that magnesium can improve anxiety symptoms, though the evidence isn’t strong.
“Even though results are somewhat mixed, given magnesium’s significance in so many anxiety-adjacent conditions, I strongly recommend ensuring that you eat enough magnesium-rich foods,” Naidoo writes in her book.
She recommends eating a quarter or half piece of a small avocado a few times a week. That can be in the form of guacamole, sliced avocado with scrambled eggs or avocado toast on sourdough bread. “It’s a powerhouse food because it’s giving you so much for a small quantity that you need to eat and so many different micro- and macronutrients,” Naidoo said.
5. Green tea
Drinking green tea during the day can provide a calming effect, Naidoo said. There’s a scientific reason, and it goes beyond the fact that sipping on a hot drink feels instantly relaxing.
“Green tea has these two antioxidants that are very powerful: EGCG (epigallocatechin gallate) and L-theanine,” Naidoo said. In a randomized, placebo-controlled trial, researchers in Japan found that L-theanine supplements reduced stress-related symptoms such as depression and anxiety.
Because green tea also contains caffeine, which can lead to an increase in anxiety when consumed in high amounts, Naidoo said that keeping caffeine consumption to under 400 milligrams a day is tolerable for people who have anxiety. An eight-ounce cup of green tea contains around 30 to 50 mg, so it’s unlikely you’ll pass that threshold unless you’re drinking other caffeinated beverages.
“Don’t drink it too late, because if it starts to impact sleep, that’s a problem, too,” Naidoo said.
6. Chia seeds or flaxseeds
Fatty fish, chia seeds, flaxseeds and walnuts are great sources of omega-3s, which are essential for brain health and development.
Though supplements containing omega-3s are popular, recent research suggests marketers have overstated the cardiovascular benefits. In many studies, Naidoo writes, dietary sources of omega-3s had better results.
For those who eat fish, Naidoo recommends incorporating salmon into their diet. For those who follow a plant-based diet, she suggests eating ¼ cup of seeds daily. Try adding a tablespoon of chia seeds and flaxseeds to salads and smoothies or stirring them into oatmeal.
7. Beans and lentils
Beans and lentils – which are types of legumes – are a great source of fiber, Naidoo said, and those are hugely important for gut health. A 2021 cross-sectional study suggests that high-fiber diets are correlated with lower levels of anxiety.
“Fiber is your friend because these foods are more complex carbohydrates, they break down very slowly in your body,” Naidoo said. “They don’t spike your insulin. They don’t spike your blood sugar.”
The nutritional differences between canned beans and dried beans are minor, she said. Buy whichever is best for you – dried beans are more cost effective – and add them to stews, soups, salads and spreads.