Fixing Your Mind Might Start With Your Stomach

Like many people diagnosed with anxiety and panic disorder, Charice Lundy was prescribed a fast-acting benzodiazepine, Xanax, to manage her symptoms. While the drug quickly placated her overactive brain, it also left her in a perpetual daze. “The Xanax got rid of the symptoms for sure, but it got rid of everything good too,” she says. “I couldn’t feel happy or excited, I just felt foggy and, like, constantly stoned.” She worked with her doctor to lower her dose over the course of several months before dropping it for good. But she knew if she was going to go off the medication, she needed another way to tackle her symptoms. Lundy would rarely leave her house because of the anxiety, and it messed with her sleeping schedule; she would have insomnia and as a result, rarely start her day before late afternoon. On top of that, there were overlapping symptoms of depression—she was diagnosed with it at 19—which included sluggishness and lack of appetite. 

Fed up that her doctors weren’t really offering any alternatives and not keen on trying new meds, Lundy, 23, turned to the internet. An active Twitter user, she followed and connected with people who subscribed to more natural routes to healing, such as yoga, herbs, and diet. Four months ago she took the first steps to change what she put on her plate. She cut out fast food first, then meat (with the exception of seafood), then progressed to a full-on vegan diet that included a probiotic supplement. When Lundy told her family she was changing her diet to manage her mood, they called her crazy. “Mental health issues run in my family and my family revolves around taking medication for them, so they pushed me not to stop mine,” she says. Nonetheless, she found her panic attacks came less frequently and she had more energy to wake up earlier each day.

Like Lundy, scientists are slowly getting on board with what many ancient medical practices have preached for centuries: You are what you eat. In the emerging field of nutritional psychiatry, researchers are studying if what you eat will, for better or for worse, affect your brain and therefore your mood. What they’re finding is in short, yes, it can. While there’s still a ways to go before nutrition becomes a mainstay of psychological treatment, years of research seems to be reaching enough of a critical mass to get the attention of mainstream medicine.

“You would logically assume that if diet impacts the health of the heart, the health of the liver, the health of the fat tissues, then diet should impact the brain,” says Joseph Hibbeln, the acting chief of nutritional neurosciences at the National Institutes of Health. Hibbeln has been researching the impact of food on the brain for more than 25 years, focusing on how omega-3s can ameliorate mood disorders like depression. In a meta-analysis published in September in the British Journal of Psychiatry, Hibbeln and his team combed through 35 randomized-controlled trials totaling 6,665 participants and found that among patients diagnosed with depression, those who took supplements with a higher concentration of EPA (a type of omega-3) saw an improvement in their symptoms. In another study, 49 depressed and suicidal patients were randomly assigned EPA supplements or placebo. After 12 weeks, the EPA group saw a 50 percent drop in depression, a 45 percent decrease in suicidal thinking, and a 33 percent reduction in the perception of stress. 

Omega-3s play a role in quashing inflammation, which is thought to be a precursor to depression. “We think that some people with depression have low-grade persistent inflammation that arises when the immune system activates a type of cell called the microglia in the brain,” explains Hibbeln. “When those cells are turned on, they set off an entire inflammatory cascade that restricts the release of dopamine, a neurotransmitter that regulates emotional responses.” However, when you eat foods with omega-3s like salmon, mackerel, and enriched dairy products, they block the microglia from being activated and instead release anti-inflammatory compounds that protect the brain. Since the body cannot produce EPA or DHA on its own, it’s necessary to get it from food or supplements, though Hibbeln urges that diet is best. (Nonetheless, supplements might be the best option if you’re on a vegan diet.)

The Mediterranean diet reduced the risk of depression, particularly among people who ate an extra 30 grams of walnuts, hazelnuts, and almonds per day.

Fish and omega-3s may have received the most airtime for their mood-stabilizing properties, but they’re not the only ones doing the heavy lifting. Generally speaking, any diet that prioritizes nutrient-dense foods like vegetables, seeds, legumes, whole grains, and healthy fats over processed foods, red meats, and junk food is helpful—something along the lines of the Mediterranean diet, which was brought up by every expert I spoke with for this story. Not only does the diet contain the omega-3 rich fish, it’s a known inflammation buster linked with curbing depression. In a 2013 randomized trial published in the New England Journal of Medicine, Spanish researchers set out to see if a Mediterranean diet could prevent cardiovascular disease more than a low-fat diet prescribed by the American Heart Association. It could. When researchers subsequently analyzed the data again, they found that it also seemed to reduce the risk of developing depression, particularly in the group of participants that consumed an extra 30 grams of walnuts, hazelnuts, and almonds per day.  

A poor diet may not only mess up the mind’s signals, it could literally shrink the brain too. A study published last September had adults 60 to 64 years old complete a diet questionnaire and undergo an MRI scan twice within a four-year period. Researchers found that adults who ate a Western diet—one higher in processed foods, fats, and sugars—had a smaller hippocampus, the area of the brain critical to learning, memory, and mental health. “The hippocampus is one of the only two parts of the brain that creates and maintains healthy neurons throughout life,” explains study author Felice Jacka, professor and director of the Food and Mood Centre at Deakin University in Australia. “Any traditional food patterns such as the Mediterranean, but also Scandinavian or Japanese diets, that are rich in healthy foods like vegetables, fruits, legumes, olive oil, and fish, helps increase specific proteins that stimulate the development of new neurons in the hippocampus. Interestingly, antidepressants also boost neural growth in the hippocampus and help this part of the brain to literally grow. We think that diet could function as an antidepressant of sorts. Of course, the unhealthy ‘junk’ foods have a negative impact on these proteins and, thus, we believe that these can act as a depressant.” Jacka’s research in nutritional psychiatry took off after a 2010 study published in the American Journal of Psychiatry that found that adhering to a Western diet was associated with a higher likelihood of depression and anxiety in women. She subsequently conducted similar population studies in adolescents and surveyed the relationship between a mother’s diet during pregnancy and her child’s risk for developing mental health problems later in life. “Over and over again, we had the same finding. It was very clear that the quality of people’s diets correlated very strongly with whether or not they had mental health conditions,” she says.  

Adults who ate a Western diet—one higher in processed foods, fats, and sugars—had a smaller hippocampus, the area of the brain critical to learning, memory, and mental health.

Emeran Mayer is a gastroenterologist at UCLA. Patients come to him with issues such as irritable bowel syndrome, acid reflux, and ulcers. Many are also dealing with anxiety, panic disorder, and depression, and he is convinced there is a connection. “Every emotion in the brain is felt in the gut, and every gut disturbance is felt in the brain—they are truly inseparable,” he says. 

It’s well-known now that the gut is more than a digestive space, it’s also the largest sensory organ, comprised of more than 100 million nerve cells, and the largest producer of serotonin in the body; such features have earned it the nickname “the second brain.” The gut is also filled with millions of microbes that produce substances that communicate with the brain and the immune system, and are thought to play a role in how we feel mentally. “Certain gut microbes stimulate the production of serotonin in the gut, which ultimately impacts levels in the bloodstream and in the brain,” explains Mayer, who recently authored a book called The Mind-Gut Connection. “Others produce gamma-aminobutryic acid, another neurotransmitter whose effects are mimicked by medications such as Xanax and Valium. If we’re low on these critical microbes or they are not communicating properly, it can ultimately lead to disturbances in the brain, and therefore mood.” In a 2013 study, Mayer and his colleagues found that women who consumed yogurt two times a day for four weeks showed a decrease in the area of the brain that process emotion—they seemed calmer. 

What keeps gut microbes in check? Fermented foods like kimchi, kefir, yogurt, and sauerkraut are beneficial as well as fiber (from vegetables, fruits, and whole grains), which acts as food, or prebiotics, for the good bacteria. Managing negative emotions plays a role too. “Chronically being angry, upset, fearful, or sad still sends a message to your gut and from your gut back to the brain and negatively impacts the microbes,” Mayer says. 

Mayer treats patients with a combination of traditional drugs in addition to more holistic remedies, like upping intake of fermented foods and probiotic supplements, skipping processed foods, fats, and sugars, as well as mindfulness strategies like meditation and cognitive behavioral therapy to work through emotional challenges. Seventy percent of these patients see an improvement and some can either lower their dosage of medication or drop it completely, he says.

It’s not a long shot to assume that Lundy’s choice of both prebiotic-favoring vegetables and a probiotic intake may have improved her symptoms. 

Despite hundreds of studies, the concept that diet can impact mental health hasn’t yet found its way to the majority of treatment protocols. A conversation about diet isn’t common in many consultations between patients and doctors, and Mayer points out that many physicians aren’t aware of the connection between the gut and the brain. 

“It’s a little bit ridiculous that it took us until 2015 to suggest the connection, but they did it, so it’s at least a step forward.”

The Dietary Guidelines for Americans—a how-to of healthy eating and its benefits, joint-produced by the USDA and the US Department of Health and Human Services—currently reads, “Emerging evidence also suggests that relationships may exist between eating patterns and some neurocognitive disorders and congenital anomalies.” Hibbeln, who consulted on the guidelines, would have probably used stronger language. “They dipped their foot in the pond but never really did the work to try to dig deeper,” he says. “It’s a little bit ridiculous that it took us until 2015 to [suggest the connection], but they did it, so it’s at least a step forward.” While the seafood section mentions that choosing fish can lower one’s risk for cardiovascular disease and obesity, the impacts on brain and mental health are absent. When I asked Hibbeln if he thought there was enough evidence to make a less diluted recommendation, he was quick to say yes, adding, “Lots of other organizations like the American Psychiatric Association and the Canadian Therapeutic Guidelines have already embraced diet to improve mental health outcomes.” Jacka mentioned that in Australia, new clinical guidelines for mood disorders advise clinicians to asses four key habits first: diet, exercise, sleep, and smoking. 

Not everyone is as quick to sing the praises of diet as a prescription for mental health conditions, however, and studies still suffer from weaknesses in design. A recent Cochrane review—a summary of all studies that are available on certain topic—analyzed 26 studies with nearly 1,400 participants who used omega-3 supplements for depression. While the authors did find a small to modest benefit, they weren’t convinced that there is enough evidence currently out there to make sweeping changes in mental health treatment. “We don’t want to put people off, because it could help certain people,” says study author Katherine Appleton. “But we also don’t want people to think that a supplement is a miracle cure and not seek formal treatment because they are waiting for a nutritional solution. People are always keen for a little pill instead of doing work. For that person, it may just not work.” 

Jacka and Mayer think that what would sway more people are double-blind, randomized controlled studies, the gold-standard of science, even though both think the evidence is there already. Instead of extrapolating from mouse studies or drawing associations from populations, these studies would essentially take a group of depressed patients, have them change their diet, and then perform various tests like stool samples and MRIs over a period of time to see if anything changes. Jacka is finishing up such a study currently and says she’s “excited about the results.” 

Appleton plays devil’s advocate but her reservations about supplements are fair. Experts seem to be in agreement that if mental health conditions are addressed in a more “holistic” way, they can’t be half-assed. That means that popping probiotics or fish oil pills will not magically erase the damage done by eating junk food, skimping on sleep, forgoing exercise, or being chronically stressed, habits that can bring on or exacerbate mental health conditions. “Healthy foods and stress management are something that have to consistently be part of your lifestyle, not just a one-time fix,” Mayer says. 

All this might entail shopping around for a physician who is knowledgeable about the powers and limits of a healthier plate.

He adds that for those suffering from severe depression or more complex conditions like bipolar disorder, diet may not be enough and psychotropic drugs may always be part of their regimen. “The more severe the symptoms are, the more difficult it is to treat them without pharmacological benefit, but a healthy diet and lifestyle interventions could certain still be part of the treatment.” Of course, that might also entail shopping around for a physician who is knowledgeable about the powers and limits of a healthier plate. 

Ultimately, the role of diet in mental health treatment might not be a cure, so much as a reprieve or even as a catalyst for other mental-health-promoting habits. After changing her diet, Lundy says she was able to sleep more regularly, which enabled her to have the energy to exercise too—these factors could be playing a role in stabilizing mood as well. And while her symptoms didn’t all disappear, she says they have greatly subsided. “Honestly, this conversation would not have happened six months ago because I would have had a panic attack,” she admits to me over the phone. “I still get anxious and sad a few times a month but it’s nothing like it used to be. I’m way more optimistic about where my life is heading.”