While the field of nutritional psychology remains in its nascency, the research surrounding food and its impact on mental health is both powerful and potentially very effective, according to recent clinical trials. The general and overall consensus is this: to support your mental health, eat real whole foods that come from nature most of the time, with limited consumption of refined and processed foods. But under the umbrella of mental health, are there any foods that can help with depression, in particular?
What does the research say?
In 2017, the SMILES trial was the first randomized controlled trial to observe the effects of a mostly Mediterranean diet for participants who were diagnosed with moderate to severe clinical depression. After 12 weeks, results showed those who adhered to the diet had significantly lower ratings of depression. In fact, a whopping 32% of the participants in the dietary intervention group achieved full remission of symptoms.
This landmark study—along with many others since then—allows us to recognize the impact food has on mental health, particularly when experiencing clinical symptoms. Here are some specific foods and dietary patterns that can potentially help reduce symptoms of depression.
Foods to eat for depression:
One important nutrient in leafy greens that has been shown to manage depression is folate, or vitamin B9. Folate helps to reduce inflammation and improve cognitive function and helps to regulate gene expression (meaning this nutrient helps to turn certain genes on and off).
There’s a reason olive oil is a staple in the Mediterranean diet! Olive oil is a monounsaturated fat that contains plenty of beneficial polyphenols. It has been shown to significantly reduce inflammation (a potential driver for mental health illnesses and conditions), most likely due to its high oleic acid content. Be sure to purchase extra-virgin and cold-pressed olive oil, if you can, as this is the least processed variety.
The neuroprotective effects of berries are related to their phytochemicals: Adding these colorful fruits to your daily diet will give you the biggest bang for your buck in terms of providing for your mental well-being.
Seafood is a nutrient-dense food that is very prominent in the Mediterranean diet. Many studies, including a meta-analysis from 2015, report that higher fish consumption overall is associated with a decreased risk of depression. In fact, in 2018, Drew Ramsey, M.D., and Laura LaChance, M.D., ranked antidepressant foods in order of nutrient density, creating a system known as the Antidepressant Food Score (AFS). In it, they describe seafood as some of the most nutrient-dense options to support the prevention of and recovery from depressive disorders.
Fatty fish (i.e. salmon, mackerel, anchovies, and sardines) are packed with important omega-3 fatty acids like DHA and EPA—both critical for mental health. Seafood is also abundant in trace minerals, which act as cofactors for crucial enzymatic reactions, like neurotransmitter synthesis. Adding seafood one to two times a week to your diet, if possible, may positively influence long-term mental health.
As mentioned previously, there is now repeated evidence to demonstrate that the Mediterranean diet may help improve symptoms of depression. One of the hypotheses as to why this is possible is the ability of the Mediterranean diet to reduce levels of inflammation. Research is continually demonstrating that inflammation plays a major role in the pathogenesis of mental health conditions, including depression, anxiety, and schizophrenia.
Many studies show that depression is associated with elevated levels of a number of biomarkers that indicate inflammation including C-reactive protein (CRP) and IL-6. (3) These inflammatory metabolites are able to access the brain and disrupt the pathophysiology of depression, including neurotransmitter metabolism. This activation of inflammatory pathways is believed to contribute to oxidative stress, which further creates inflammation in the brain called neuroinflammation.
Another potential mechanism in which food exerts its effects on our mental health is through our gut microbiota, due to the gut-brain axis. There are millions of diverse microorganisms living inside of our guts, which influence many aspects of our health, including immune function, mental functioning, and cardiovascular health.
The most direct influence on our gut microbiota is our diet, which is responsible for up to 60% of the bacteria variation. Dysbiosis, or an alteration in the composition and environment of our gut microbiota, can lead to increased intestinal permeability. This can allow contents, such as bacterial metabolites from the gut, to cross into our blood circulation—otherwise known as leaky gut (which is not yet a widely recognized medical condition but often discussed in the functional medicine community). This could lead to further inflammation in the body as these inflammatory products are circulated, contributing to neuroinflammation.
In order to both create a healthy gut microbiota and help decrease levels of inflammation, following a Mediterranean-style diet may be optimal. With a focus on fresh vegetables and fruits, nuts and seeds, seafood, and plenty of olive oil, this dietary pattern will do all of the above and potentially help improve mental health by decreasing symptoms of depression.
