Eat smart; the effects of your diet on your mental health

Research suggests that what we eat does not only affect our physical health, but also our mental health and how we feel. More and more studies are showing us that a healthy diet is strongly linked to increased concentration, better stress management, improved sleep and better emotional wellbeing, while a poor diet is linked to increased rates of depression, anxiety and other mood disorders. Nutritional psychiatry is the term used to describe this rapidly emerging field, and we are learning more about the relationship between food and the mind every day.

Essential nutrients

There are many nutrients which play a role in brain health, and if we do not get enough in our diets, our mental health may suffer. One example is L-Tryptophan, an essential amino acid which is used to produce serotonin, our happy hormone. Our bodies cannot produce L-Tryptophan and it must be obtained through protein sources in the diet. Food rich in this amino acid include chicken, eggs, fish, milk, oats, nuts and seeds.

B-vitamins are a micronutrient which play a role in brain health, particularly vitamin B12. Inadequate levels in the body can cause depression, cognitive difficulties and memory loss, among other symptoms. Vitamin B12 is almost exclusively found in animal foods, including beef, chicken, eggs and dairy products. Non-animal sources include nutritional yeast and fortified foods.

Omega 3 fatty acids are also well known for being good for our brains. They are a healthy fat involved in neuron growth, gene expression, and dopamine and serotonin transmission. Several clinical trials have shown that taking adequate amounts of omega-3 improved symptoms of depression, ADHD, bipolar disorder and schizophrenia. Good sources of omega 3 include oily fish including salmon, mackerel, tuna and sardines, walnuts, flaxseeds and chia seeds.

Gut microbiome

Gut health is currently a very hot topic and for good reason. Maintaining a healthy gut microbiome is imperative to optimising brain function, and inflammation of the gut has been linked to causing anxiety and depression. This two-way relationship is referred to as the “gut-brain axis”.

The best thing for improving the health of your gut is by including lots of diversity in your diet, and eating lots of plant foods such as fruits, vegetables and beans. Additionally, try to include foods that feed the good bacteria in the gut (called prebiotic foods) including garlic, banana, asparagus, onions, tomatoes and berries. Avoiding refined sugars is very important as they cause bad bacteria to grow and wreak havoc on the gut.

Eating well

While there is no magic superfood that will cure depression, a generally healthy diet high in fruits and vegetables, legumes, nuts and seeds, grains, lean meats and some dairy products is a good place to start. The Mediterranean diet in particular has been strongly researched around its benefits for mental health and anti-inflammatory properties, which has a strong focus on including lots of plant foods as well as plenty of healthful fats like olive oil, nuts and seeds. Foods such as refined carbohydrates, sugary drinks, highly processed food, unhealthy fat, salt and alcohol should be limited to every now and then.


Appleton J. (2018). The Gut-Brain Axis: Influence of Microbiota on Mood and Mental Health. Integrative medicine (Encinitas, Calif.), 17(4), 28–32.

Butler, M. I., Mörkl, S., Sandhu, K. V., Cryan, J. F., & Dinan, T. G. (2019). The Gut Microbiome and Mental Health: What Should We Tell Our Patients? Canadian journal of psychiatry. Revue canadienne de psychiatrie, 64(11), 747–760.

Clapp, M., Aurora, N., Herrera, L., Bhatia, M., Wilen, E., & Wakefield, S. (2017). Gut microbiota’s effect on mental health: The gut-brain axis. Clinics and practice, 7(4), 987.

Firth, J., Gangwisch, J. E., Borisini, A., Wootton, R. E., & Mayer, E. A. (2020). Food and mood: how do diet and nutrition affect mental wellbeing?. BMJ (Clinical research ed.), 369, m2382.

Jenkins, T. A., Nguyen, J. C., Polglaze, K. E., & Bertrand, P. P. (2016). Influence of Tryptophan and Serotonin on Mood and Cognition with a Possible Role of the Gut-Brain Axis. Nutrients, 8(1), 56.

Rao, T. S., Asha, M. R., Ramesh, B. N., & Rao, K. S. (2008). Understanding nutrition, depression and mental illnesses. Indian journal of psychiatry, 50(2), 77–82.

Reimers, A., & Ljung, H. (2019). The emerging role of omega-3 fatty acids as a therapeutic option in neuropsychiatric disorders. Therapeutic advances in psychopharmacology, 9, 2045125319858901.

Young, L. M., Pipingas, A., White, D. J., Gauci, S., & Scholey, A. (2019). A Systematic Review and Meta-Analysis of B Vitamin Supplementation on Depressive Symptoms, Anxiety, and Stress: Effects on Healthy and ‘At-Risk’ Individuals. Nutrients, 11(9), 2232.

Mental Health