The Link Between Omega-3 and Depression

The human race is currently partaking in an unprecedented, massive experiment. People, in a short period of time, have almost completely changed how their lives are structured and researchers have only recently begun to examine the results. The United States Department of Health and Human Services (2000) reported that unhealthy lifestyles are responsible for most of the top ten cases of mortality and morbidity in the country. The lifestyle of the average person today (featuring many more conveniences, luxuries, and innovations) is quite different than that of our recent ancestors. Present day lifestyles are fast-paced and demanding with the majority of daylight time spent indoors. Diets are dominated by processed convenience food while sleep is often shortened and disturbed. Sedentary lifestyles are the norm while social connectedness has decreased.

Our lifestyles have changed dramatically over the last few centuries but our genes and bodies have remained largely unchanged. According to Dr. Ilardi, (a psychologist studying the effect of lifestyle change on depression at the University of Kansas) the disconnect between the intended evolutionary purpose of our genes, brains, and bodies and our modern lifestyle may lead to depressive disorders.  Conversely, research shows that numerous lifestyle factors such as dietary omega-3 essential fatty acids (EFAs) supplementation, bright light exposure, increase in restful sleep, aerobic exercise, fighting persistent negative thoughts, and social connectedness have demonstrated to have antidepressant effects.

This blog post will focus on omega-3 EFAs, a type of polyunsaturated fatty acid, and is naturally occurring in marine and plant oils.  However, humans must acquire omega-3 EFAs through diet because the human body cannot produce omega-3 EFAs.  Strikingly, the common American diet is particularly rich in omega-6 EFAs and often the average diet does not provide the optimal dosage of omega-3 EFAs.

The link between omega-3 EFAs and depression stems from numerous studies examining depression rates across countries and diets.  Populations that contain a higher proportion of fish – a rich source of omega-3 EFAs – in their diet have lower rates of depression.  Furthermore, depressed individuals often have reduced omega-3 EFA levels. Careful scientific review has indicated that the therapeutic effect derives from omega-3 EFAs rich in eicosapentaenoic acid (EPA). However, ignoring the ratio of EPA leads to a fading of a therapeutic effect. The antidepressive effect from EPA-rich omega-3 EFAs is thought to come from a reduction in inflammation of the brain.

Omega-3 EFA supplements can be purchased at drugstores or health food stores.  It is recommended that the brand provide at least 1000mg of EPA per day (the amount that has been shown to decrease depressive symptoms and improve mood). Aside from supplements, high levels of EPA rich omega 3 EFAs can be found in small green plants and the animals that eat them (particularly wild caught fish and grass fed meat). Omega 3 EFAs are a blood thinner and those already taking blood thinners or who experience easy bruising should be cautious. There are no other known adverse side effects of omega-3 EFAs supplementation. However, it is always recommended that individuals inform a healthcare professional of any changes or additions to medications or supplements.


Yevgeny Botanov, PhD

Research Associate
Behavioral Research & Therapy Clinics
University of Washington