How Your Diet Can Lead to Depression

If you are what you eat, can that extend to your mood? The simple answer is yes, say nutritionists and researchers who have looked into whether what you eat can increase or decrease the risk for or symptoms of depression.

“Diet may have a significant effect on preventing and treating depression,” says Digant Dave, director of mental health and addiction services at El Camino Hospital in Mountain View, California. First among these potential effects is often seen on appetite.

“Depression can either increase or decrease appetite, and negative mood states have been shown to stimulate a preference for foods high in sugar, fat and/or salt,” so-called comfort foods, Dave says. It makes sense that your body might crave these tried-and-true foods in times of stress or distress.

The problem with that, however, is frequently indulging in these less nutritious foods can lead to a “lower-than-recommended intake of brain-essential nutrients, such as B vitamins, zinc, folate and magnesium,” Dave adds. Your body needs those nutrients to be at optimal levels to help make the brain chemicals that can make you feel better and less depressed.

Emotional eating can also become a problem, Dave says. “Emotional eating is eating in response to emotional need as opposed to physiological need.” If you reach for comforting food as a coping mechanism when you’re feeling down or lonely, that can lead to weight gain. “This behavior can lead to further feelings of embarrassment, disgust and guilt that can make the person even more depressed, leading to a vicious cycle,” Dave explains.

While the cause-and-effect relationship between food and mood seems fairly straightforward, there is one complex communication that goes on between the brain and the gut that makes it all work.

Studies have suggested that the gut microbiota – that’s the multitude of bacteria that live inside the gut and contribute to overall health in a wide range of ways – is significantly different in healthy people than it is in depressed people, says Evette Khaew, a registered dietitian and clinical nutrition manager at El Camino Hospital in Mountain View, California.

The foods you eat feed the bacteria in the gut, and different strains of these microbes prefer to eat different things. “Generally, the human gut microbiota consists of five phyla,” or types of bacteria, Evette explains. These include:

Studies of fecal samples collected from both mice and humans, for example, found that “Bacteroidetes and Firmicutes were the predominant phyla that appeared to be the most affected in depression,” she explains.
In addition, your body needs adequate supplies of a whole bunch of nutrients to help support its ability to manufacture neurotransmitters such as serotonin, also sometimes called the feel-good chemical. Neurotransmitters are chemicals that carry messages between neurons.

“Serotonin is a neurotransmitter that helps regulate sleep, appetite, moods and inhibits pain,” explains Eileen Chaves, a pediatric obesity psychologist working at the Center for Healthy Weight and Nutrition at Nationwide Children’s Hospital in Columbus, Ohio. “It is primarily produced in the gastrointestinal tract, which is lined with millions of nerve cells, or neurons. This means that our digestive systems don’t just help us digest and absorb our food, but also play a significant role in how we feel.”

How well your neurons function – and produce serotonin – is influenced by your gut microbiome, which thrives on “good” bacteria. Good bacteria species include Lactobacillus (in the phylum Firmicutes) and Bifidobacterium (in the phylum Actinobacteria) and are often found in probiotic supplements that aim to support gut health. That good bacteria, in turn, thrives on whole foods that are high in fiber and full of nutrients such as leafy greens, healthy fats and whole grains.

If you have depression, what you eat might improve or worsen symptoms. “The idea is that eating a diet rich in high-quality foods that provide significant nutrition, including vitamins, minerals and antioxidants, may help nourish the brain and protect it from free radicals, or oxidative stress,” says Mia Syn, a registered dietitian based in Charleston, South Carolina, and author of “Mostly Plant-Based.”

In general, Syn recommends eating a diet featuring:

“This type of diet is often described as the Mediterranean diet. Studies have shown that the risk of depression is 25% to 35% lower in those who eat this type of diet,” Chaves says.

Khaew adds that a diet of “whole, unrefined foods with protein, healthy fat and fiber help to keep blood sugar stable after meals, which positively contributes to mood.”

Gaby Vaca-Flores, a registered dietitian and founder of Glow+Greens, a nutrition and skin care consultancy based in Santa Monica, California, notes that “while food won’t directly treat symptoms of depression, following a healthy diet can support your overall mental well-being.”

More specifically, there are a few compounds within these foods that have also been studied and appear to have an effect on depressive symptoms. These include:

On the flip side, there are some foods you should limit if you have depression. “Knowing what foods to eat less of for improved mental health is helpful,” Chaves says. “I typically never advise that the families I work with ‘avoid’ foods. Instead, we talk about knowing what are ‘sometimes’ foods and what are ‘anytime’ foods so that we do not inadvertently set up a system of food deprivation that might make certain foods seem more tempting and, therefore, if you eat them, make you feel guilty or have thoughts about being a ‘bad’ person.”

Some foods to consider limiting include:

Chaves notes that there’s “never a bad time to start incorporating more whole foods into your diet. Sometimes changing what you eat or how you eat might feel overwhelming, especially if you are in depression, when everything can feel overwhelming.”

If that’s the case, she recommends making a small goal to eat just one more piece of fruit, an additional vegetable or serving of whole grains than you did the day before. That’s “significant progress, and if you aren’t able to meet your goal, that’s OK; you can try again the next day,” she says.

Over time, small changes start to add up, and you may notice that you’re feeling better. These improvements may include:

“Starting to notice these types of changes can help you recognize your progress and give you the ability to keep up changes and introduce new ones,” Chaves says.
In addition to talking about what to eat, “proper nutrition also includes a discussion of the number of meals to eat per day,” says Dr. James S. Pratty, a psychiatrist who’s board certified in addiction medicine and serves as medical director of behavioral health for Brand New Day, a health plan based in Southern California.

That number can vary based on individual goals; for example, someone who’s trying to lose weight may be advised to eat five times per day. “For someone who is not wanting to lose weight and is wanting to follow a healthy dietary regimen, eating three times per day is significantly important,” he says. “The time of the last meal is also very important. The last meal of the day should be at least three hours before someone is going to bed.”

If you’re prone to emotional eating or using food to cope with difficult emotions, Dave says you should learn to eat mindfully. Eating mindfully means paying attention while you’re eating, so taking your time, savoring each bite and not eating in front of the television. He also suggests addressing feelings and resolving to consume a healthy diet because it can help you get out of that cycle of emotional eating. A nutritionist or therapist can help you learn to eat more mindfully and find healthier coping strategies when the going gets tough.

Lastly, Pratty says that while eating a healthy diet can support your efforts to manage depression, “a dietary regimen alone is not sufficient to promote good health.” You should seek help from your primary care provider or a mental health professional to get appropriate treatment for any mental health concerns.

Pratty also recommends several other “good living habits” that can help keep depression in check, such as: