Experts Say Nutritional Psychiatry Is A Thing — But How Does It Work?

After a bad day, you might turn to your favorite food to help lift your spirits. But eating your favorite comfort food may not be the only way you can utilize your diet to improve your mental wellbeing. According to an emerging field of research called nutritional psychiatry, there may be a connection between the food you eat and your mental health. Historically, food has been linked only to physical health, but now that we’re learning that physical and mental health are intrinsically intertwined, researchers have also discovered that diet can impact mental health issues such as depression and anxiety. From this concept emerged nutritional psychiatry, a field of study that looks at the relationship between dietary patterns and risk of mental health disorders. Although the concept is fairly new, it’s quickly gaining traction.

The evidence base for nutritional psychiatry is robust, according to UK-based psychologist nutritionist Kimberley Wilson. She mentions that several placebo-controlled trials have shown that improved nutrition plays a role when it comes to mood, aggression, concentration, and even dementia-risk. The new part, she says, is translating that research into professional training and clinical practice.

Although it does take time for new concepts and research to become mainstream in practice, there are a growing number of professionals interested in the topic. It’s also worth noting that this concept has actually been practiced for a long time in different cultures. Both Traditional Chinese Medicine (TCM) and Ayurveda, an ancient traditional Indian principle and lifestyle, use food to promote balance in the body.

“I grew up learning yoga, meditation and mindfulness from my grandparents,” says Nutritional psychiatrist Dr. Uma Naidoo, who is Hindu. “When I was in medical school, these were not part of mainstream medicine. Now at one of the largest teaching hospitals in the world where I also work, there is the Benson Henry Institute for Mind Body Medicine at Massachusetts General Hospital. So while nutritional psychiatry is a young field of psychiatry, it has immense potential to provide positive change to how we see food as medicine.”

Food impacts mental health in various ways. Most obviously, food contains nutrients, the building blocks for everything in the brain and body. “The brain requires the full array of macronutrients (ex: proteins and carbohydrates) and micronutrients (ex: vitamins and minerals) in the right amounts and combinations to support brain health and function,” says psychologist and nutritionist Dr. Nicole Beurkens. “If we don’t get enough of the nutrients we need from the food we eat, our mental health suffers as a result.” On the flip side, when one eats a varied nutrient-dense diet, they support brain function and strengthen one’s mental health, Beurkens says.

Nutrients are also required to produce neurotransmitters, complex chemical messengers that affect every cell, tissue, and system in your body, including your mood. One such neurotransmitter is serotonin, often called the “good mood hormone.” Serotonin relays signals between nerve cells and appears to play a role in mood, emotions, appetite, and digestion, although scientists are still learning exactly how. “Serotonin synthesis requires iron, calcium and vitamin B6,” says Wilson. “Deficiencies in these nutrients will impair serotonin production and may have negative effects on mood and wellbeing.”

Additionally, recent discoveries have found that the gut and brain are actually connected through what they call the “gut-brain axis.” Not only is the majority of your serotonin produced in the gut, but your microbiome and brain communicate through something called the vagus nerve. “This nerve serves as a bidirectional superhighway of information in the form of chemicals that keep both organs highly connected,” says Naidoo.

Most nutrition studies tend to be observational, which only show correlation, not causation. They’re also limited because they often rely on self-reporting, which can be inaccurate. However, research is still promising. One controlled study from 2017 compared two groups of people, both with clinical depression. The first group met with a dietitian and adhered to a Meditarranean diet, which focuses on plant foods like fruits, vegetables, nuts, grains, and seafood with a moderate amount of poultry and dairy. The second group was a control group that made no dietary changes. Although both groups were on antidepressants, the goal of the study was to see if diet could help in addition to medications. The researchers found that at the end of the study, about a third of the diet-change group were no longer classified as depressed, compared to only 8% of people in the control group.

When it comes down to what specific foods can help with mental health, it’s less about eating one specific food and more about your overall diet. As you can imagine, foods that are richest in nutrients have the biggest impact. “Nutrient-dense foods are the goal when we’re talking about supporting mental health,” says Beurkens.

Foods That Improve Mood

Foods High In Omega-3s

Foods like fish are a great addition to your diet because they contain omega-3 fatty acids, an anti-inflammatory nutrient important for brain health. A recent meta-analysis found that taking fish oil supplements improved symptoms in people with depression, although the greatest improvements were found in those who combined the fish oil supplements with antidepressants. Fish high in omega-3s include salmon, sardines, mackerel, and herring.

Leafy Greens

Mom always said to eat those greens, and for good reason. Leafy greens such as spinach, kale, cabbage, romaine, and spring mix lettuce are quite nutritious, and they are particularly rich in folate, a B vitamin that’s important for mood regulation. Low levels of folate have been linked to an increased risk for depression. “Sufficient consumption is associated with improved moods and sharper minds,” says Naidoo.

Polyphenol-Rich Foods

Polyphenols are natural compounds believed to boost the body's natural defense systems, stabilize free radicals, and reduce oxidative damage. In fact, research shows that one of the reasons a Meditarranean diet might be so effective at helping with depression is because of its high-polyphenol content. “Polyphenol-rich foods like berries, leafy green vegetables, tea, coffee, herbs and spices have both acute and long-term positive effects on brain and mental health,” says Wilson.

Proteins

“Meats and seafood contain B vitamins, zinc, iron, and protein — all of which are necessary for regulating mood, anxiety, behavior, energy levels, and much more,” says Beurkens. Many types of protein such as beef, turkey, and chicken contain tryptophan, an amino acid that converts to serotonin. Other sources of protein, like nuts, can be beneficial as well. “Nuts like cashews and almonds contain magnesium and zinc, two minerals essential for supporting mental health,” she says.

Prebiotics and Fermented Foods

Because gut health and brain health are connected, it’s important to eat gut-supporting foods. Prebiotic foods, which include foods such as onions, leeks, garlic and asparagus, feed the gut microbes, while probiotic foods help with the balance of good bacteria. “Live active cultures, found in fermented foods such as kimchi and kombucha, provide more healthy bacteria to our guts, which reduces inflammation, and supports a healthy brain, healthy hormone levels, and happy moods,” says Naidoo.

Foods That Impair Mood

Just as certain food groups can help with mood, some can hurt as well. “In terms of foods that damage the brain, the main message from the research seems to be to limit sugar-sweetened beverages such as fizzy drinks,” says Wilson. “Consumption of free-sugar in this form has been found to increase inflammation in the brain and impair mood and cognitive performance.”

Foods that are heavily processed, high in sugar, and low in nutrients tend to be the most detrimental to mental health outcomes, as they not only cause drastic changes in blood sugar but also lack those essential vitamins and minerals. “Although they may taste good, these types of foods do not provide enough of the nutrients needed to support mental health, sustained energy, quality sleep, etc.,” says Beurkens.

All this being said, there are still limitations when it comes to using food to help with your mental wellbeing. “Mental health conditions are incredibly complex and their development may be influenced by factors such as genetics, upbringing, trauma, and poverty, as well as personal health and lifestyle factors,” says Wilson. Although some trials were successful in treating those with mental health issues with food alone, it’s still unclear who will respond best to nutritional interventions. “Nutrition alone is unlikely to help someone who already has a pretty healthy diet,” she says.

However, most agree combining nutritional therapies with other forms of treatment such as Cognitive Behavioral Therapy (CBT) or medications such as antidepressants can be very effective. “Nutritional psychiatry does not exclude the use of medications or other therapies,” says Naidoo. “It is intended to complement other treatments when necessary or be a standalone treatment when appropriate, too.”

As the research grows, experts agree there’s no harm in including more nutrient-dense foods into your diet in the hopes that it may impact your mood. “We all have to eat, we eat every single day, so why not eat for our better mental well being?” says Naidoo. “Unless you had a food allergy or intolerance, the benefit of eating with awareness outweighs any potential risk.”