The Relationship Between Food and Mental Health
By: Jula He | Updated: October 1st, 2024
As people worldwide grappled with increased levels of stress, depression, and anxiety in the past year, many turned to their favorite comfort foods like ice cream, pastries, pizza, and hamburgers. However, recent studies have suggested that these sugary and high-fat comfort foods, despite their soothing appeal, are the least likely to have a positive impact on our mental health. Instead, it appears that whole foods such as vegetables, fruits, fish, eggs, nuts, seeds, beans, legumes, and fermented foods like yogurt may offer better mental health benefits.
These findings have emerged from the field of nutritional psychiatry, a growing area of research that examines the connection between diet and mental well-being. While it may seem like common sense that certain foods can promote brain health much like they promote heart health, historical nutrition research has primarily focused on the physical aspects of our diet rather than its impact on mental health. For a long time, the potential influence of food on happiness and mental well-being was largely overlooked.
Over time, a body of research has provided intriguing insights into how food might affect our moods. A healthy diet supports a healthy gut, which communicates with the brain through the gut-brain axis. The microbes in our gut produce neurotransmitters like serotonin and dopamine, which play a crucial role in regulating our mood and emotions. The gut microbiome has also been implicated in mental health outcomes, with research showing its involvement in conditions such as major depressive disorder.
Large population studies have further reinforced the connection between nutrient-rich diets and improved mental well-being. For example, a study from 2016 tracked 12,400 individuals for about seven years and found that those who increased their consumption of fruits and vegetables reported higher levels of happiness and life satisfaction.
However, large observational studies can only establish correlations, not causation. This leads to questions about causality: Do anxiety and depression drive people to choose unhealthy foods, or do people who are happy and optimistic naturally gravitate toward nutritious foods? Can a healthy diet directly enhance one's mood?
The first significant trial exploring the food-mood link was published in 2017. Researchers investigated whether dietary changes could help alleviate depression and recruited 67 clinically depressed individuals. They divided the participants into two groups: one received guidance on following a traditional Mediterranean-style diet, while the other received social support but no dietary advice. Both groups initially consumed sugary, processed foods and low-fiber, protein, and fruit/vegetable diets. However, the diet group made substantial changes, replacing unhealthy options with whole foods like nuts, beans, fruits, vegetables, whole grains, and lean proteins.
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Crucially, both groups continued taking any prescribed antidepressants or medications throughout the study. The study aimed to determine if a healthier diet could provide additional benefits alongside medication, exercise, sleep, and other lifestyle factors.
After 12 weeks, both groups showed improved depression scores, as expected in a clinical trial with added support. However, the group following the healthy diet experienced significantly greater improvements in depression, with about one-third of participants no longer classified as depressed, compared to only 8 percent in the control group.
These results were remarkable for several reasons. The diet improved mental health without leading to weight loss. Moreover, it was cost-effective, with participants who switched to a healthier diet saving money on their food expenses.
The recommended foods were relatively affordable and readily available, including items like canned beans, lentils, canned seafood, frozen produce, and conventional produce. Felice Jacka, the lead author of the study, emphasized that while eating a salad won't cure depression, there are simple steps individuals can take to improve their mental health, such as increasing their intake of plants and healthy foods.
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In another investigation led by Jacka, 67 adults dealing with depression were randomly assigned to either seven individual nutritional counseling sessions with a dietitian or seven sessions focused on social support over a span of 12 weeks. The dietitian assisted participants in making dietary modifications, including reducing the consumption of unhealthy foods and increasing their intake of nutrient-rich options like fruits, vegetables, fish, and legumes. The results showed that while only 8 percent of the control group experienced remission, nearly one-third of the dietary intervention group did.
These studies contribute to the growing body of evidence in the field of nutritional psychology, which examines the role of nutrition—whether in terms of dietary patterns, comprehensive multinutrient supplements, or specific vitamins, minerals, and nutrients—in both the development and treatment of mental health issues. Although much of the research is still limited to single-case studies and observational investigations, with researchers themselves advocating for more rigorous and extensive research designs as well as larger and more diverse study samples, it offers promising indications of potential new prevention approaches and treatments for individuals facing a broad spectrum of psychological challenges.
