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.The Mediterranean diet reduced the risk of depression, particularly among people who ate an extra 30 grams of walnuts, hazelnuts, and almonds per day.
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.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.
"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."
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."All this might entail shopping around for a physician who is knowledgeable about the powers and limits of a healthier plate.