Colorful bowl of salad

Years of research have demonstrated that a healthy diet can help cut the risks of illnesses, from diabetes to some cancers. Now, more and more studies suggest that food choices may also affect emotions—even for the 15 percent of women and 10 percent of men older than 65 with depression.

“Research shows that what you eat does impact your mood,” says Umadevi Naidoo, M.B.Ch.B., director of Nutritional and Lifestyle Psychiatry at Massachusetts General Hospital in Boston.

For instance, a study published last April in the European Journal of Nutrition found that people with depression who scored high on the Alternate Healthy Eating Index (consuming a diet rich in produce, whole grains, nuts, and omega-3 fatty acids) were less likely to have a recurrence of symptoms over an 11-year period.

An analysis of 16 studies—which included almost 46,000 people—published earlier this year in the journal Psychosomatic Medicine found that adults who followed overall healthy diets, such as high-fiber, veggie-focused eating plans, were less likely to have depression symptoms.

Just how much food choices may affect mood is not clear, partly because nutrition research findings can be difficult to pin down. But patterns are emerging. 

The Gut-Brain Link

If you’ve ever had a “gut wrenching” experience, you know that your gastrointestinal system is sensitive to your emotions.

Specifically, it’s your microbiome—the ever-changing mix of good and bad bacteria in your gastrointestinal tract, according to a study published last February in the journal Nature Microbiology. When researchers looked at the microbiomes of more than 2,000 adults, they found that those who were depressed had lower levels of some “healthy” gut bacteria.

More on Mood

“We know that the good bacteria in your gut produces a lot of neurotransmitters implicated in mood, like norepinephrine and gamma-aminobutyric acid (GABA),” says Drew Ramsey, M.D., a psychiatrist at Columbia University College of Physicians and Surgeons in New York City and author of “Eat Complete” (Harper Collins, 2016).

And though the mood-related hormone serotonin is usually thought of as a brain chemical, more than 90 percent of it is made in your gastrointestinal tract.

The Issue With Ultraprocessed Foods

Studies have associated diets high in “ultraprocessed” foods—such as soft drinks, instant soups, and packaged chicken nuggets—with a higher risk of obesity and cardiovascular disease.

There may be links to mood, too. A study published in May in the European Journal of Nutrition, which examined the diets of almost 15,000 people, found that those who ate the most ultraprocessed foods had a 33 percent higher risk of depression than those who ate only minimal amounts.

“These foods tend to be lower in essential nutrients such as omega-3 fatty acids and B vitamins that play a crucial role in brain health,” says Samantha Heller, R.D., a nutritionist in New York.

Highly processed foods also typically contain little fiber, Heller says, and fiber helps keep your microbiome—and possibly your mood—in better balance.

Many are also loaded with sugar and additives, such as artificial flavoring. Such substances “feed the bad bacteria in your gut, which in turn can impact your mood,” Naidoo says.

An example: A 2017 review published in the journal Scientific Reports found that men who consumed the most sugary foods and drinks were almost 25 percent more likely to have depression.

Eat Your Way Happy?

There’s no guarantee that specific foods will make you happier, but experts have some suggestions that may be beneficial:

Start small. Begin with easy changes, such as replacing sugary desserts with fresh or no-sugar-added frozen fruit and a bit of dark chocolate.

Focus on whole foods. Make fresh and unpackaged foods, such as produce and whole grains, the centerpiece of your diet, and limit highly processed items to one a day (or less), Naidoo says.

Check ingredients lists: Ultraprocessed foods usually have long ones and additives such as artificial flavors; added sugars, such as corn or malt syrup; and preservatives.

Go veggie. Getting more produce may be good for body and mind. A U.K. study published last January in the journal Social Science and Medicine found that the more fruits and vegetables people consumed, the better their mental well-being over a three-year period. “Even just making sure that you incorporate five servings of fruits and vegetables in your diet every day can reap benefits,” Naidoo says. For extra credit, focus on veggies such as watercress, spinach, mustard greens, lettuces, and Swiss chard, and fresh herbs such as cilantro and basil (plus, shellfish like clams and mussels). All earn a high Antidepressant Food Score, which Ramsey created based on available data on the effects of specific nutrients on mood.

Coddle your microbiome. Include foods that contain live “good” bacteria cultures (aka probiotics)—such as yogurt, kefir, and fermented veggies like sauerkraut—in your daily diet, Ramsey says. And eat foods with prebiotics, a fiber that feeds good gut bacteria. Good sources include garlic, leeks, asparagus, onions, chicory root, and Jerusalem artichoke.

Look to the Mediterranean. Some research supports the role of a Mediterranean-like diet—one that’s rich in fruits, veggies, whole grains, fatty fish, nuts, and olive oil. A possible reason: The diet contains plentiful amounts of folate and vitamin B12, which have been associated with a reduced risk of depression, says Konstantinos Argyropoulos, M.D., Ph.D., a psychiatrist at the Hellenic Open University in Greece. Mediterranean-style diets may also reduce inflammation, which some research has linked to a higher depression risk.

Make Mealtime More Enjoyable

When it comes to eating for a better mood, it’s about more than what’s on the end of your fork, Heller says. Try the following:

Dine with others some of the time. Older adults who eat alone are more susceptible to depression, according to a 2015 study published in the medical journal Age and Ageing. If it’s challenging to find meal companions, invite a neighbor over for a meal or check out community or senior center programs.

Choose colorful foods and arrange them nicely. A pretty plate is key if you find that your appetite is smaller than it once was. “We are visual eaters, so when you see food, your salivary glands start up, which stimulates appetite,” says Vandana Sheth, R.D.N., C.D.E., a spokesperson for the Academy of Nutrition and Dietetics.

Eat mindfully. A 2018 study published in the Journal of Affective Disorders found that people who do this have lower rates of depression. So at mealtime sit, don’t stand, and avoid munching in front of the TV, Sheth says. And take the time to savor each bite, chewing slowly so that you can enjoy all the flavors and textures of your food.

When You Need More Help With Mood

Making the right dietary choices may have a positive effect on mood, but it’s important to know when you might need more care for mood issues.

Periodic feelings of anxiety, sadness, or irritability are normal, as is occasional trouble sleeping or appetite changes. But if any of the above persist for more than two weeks, see a doctor, Ramsey says.

Start with your primary care doctor, who can screen you for depression and check for medical issues that may be dampening your mood, such as a thyroid disorder. If your doctor thinks you may be depressed, she may refer you to a therapist for talk therapy and/or to a psychiatrist to discuss medication therapy.

If you’re unsure whether you need help, you can take a short self-assessment at the Anxiety and Depression Association of America’s website.

Editor’s Note: This article also appeared in the October 2019 issue of Consumer Reports On Health.