Omega 3 benefits in treating depression

According to the World Health Organization (), more than 300 million people around the world suffer from some major depressive disorder, which represents more than 3% of world health problems. Due to its negative impact on the individual (depressed mood) and on society (it produces a high rate of absenteeism from work), the treatment of it has been and continues to be an area in constant evolution. For this reason, in addition to drug and drug treatment, in recent years studies have been carried out to evaluate which dietary components could influence its prevention and treatment: among them, we highlight the Omega-3 fatty acids.

Functions of omega 3 acids

Within the omega 3 family, there are two fatty acids especially interesting for the functions they perform: the eicosapentaenoic (EPA) and docosahexaenoic (DHA). Among these functions we highlight:

• Maintenance of brain function.
• Maintenance of the immune system.
• Reduction of inflammatory mediators (pro-inflammatory cytokines and prostaglandins).
• Improvement of dopaminergic and serotonergic neurotransmission.

These fatty acids, being considered essential, must be ingest through food such as blue fish, shellfish, some nuts and seeds, although we can also supplement this dietary intake by taking supplements rich in omega 3. In fact, the growing interest in these types of fats has promoted the appearance of EPA and DHA supplements that have been suggested to have beneficial effects in the treatment of depression. However, the European Food Safety Authority, although it recommends the intake of 250 mg EPA and DHA for healthy adults, has not reported positively on the effects of these fatty acids on cognitive function or mood of people and the United States Food and Drug Administration (FDA) has not approved the use of supplements formulated with EPA and DHA for the treatment of any psychiatric disorder.

What do studies say about omega 3 and depression?

There are already numerous studies that have tried to examine the effectiveness of supplements of omega 3 in depression, obtaining divergent results due, in part, to the methodological differences between the trials (dose and duration of supplementation) and to differences in the composition of the supplements (EPA: DHA ratio). Specifically, a review published in March 2010 in the "American Journal of Clinical Nutrition" showed the difficulty of making clear recommendations regarding the role of omega 3 acids in depression, due to the heterogeneous nature of the clinical trials carried out up to date. Other clinical trials published in the Cochrane Library (2015) investigated the effect of omega 3 fatty acid supplements compared to placebo tablets and with a: the results showed a small positive effect of omega 3 fatty acids compared to placebo, although not very relevant as the evidence was of low quality.

Omega-3 acids as treatment adjuvants in depression

Even taking into account that, in general, omega 3 fatty acids should not be prescribed as an alternative treatment for depressive disorders, there is some evidence to support the use of EPA and DHA to enhance the effectiveness of treatment antidepressant. In fact, the American Psychiatric Association (APA) recommends a daily dose of 1,000 mg of EPA + DHA (with a content of at least 60% EPA) as an adjunctive treatment in depression and other psychiatric disorders. Likewise, since depressive disorder is an inflammatory pathology that produces oxidative damage, those patients who carry out a diet insufficient in omega 3 could respond favorably to the consumption of this type of fats and, specifically, to the use of supplements with EPA and that could modulate said inflammation improving both adherence to treatment, as well as the prevention of relapses in depression.

General conclusions and recommendations

With all the above, we can conclude that, despite the ambiguity in the results, omega 3 fatty acids have the potential to to get better many of the biological alterations associated with depression, especially the inflammatory component, which is why it is recommended to carry out a healthy diet rich in oily fish (salmon, tuna, sardines, mackerel ...), nuts and seeds (flax, chia, etc.) whose intake has been associated with a lower risk of suffering from a depressive disorder. In addition, supplements rich in EPA / DHA have shown positive effects in the prevention and reinforcement of the treatment of this pathology. However, more studies are needed to better understand the mechanisms of action of omega 3 acids, and there is currently insufficient evidence to support their use as monotherapy nor is it proposed as an alternative to antidepressants.

• The growing interest in this type of fat has promoted the appearance of EPA and DHA supplements which have been suggested to have beneficial effects in the treatment of depression.
• The European Food Safety Authority, although it recommends the intake of 250 mg EPA and DHA for healthy adults, has not reported positively on the effects of these fatty acids on people's cognitive function or mood.
• More studies are needed to better understand the mechanisms of action of omega 3 acids and today insufficient evidence is available that support its use as monotherapy, nor is it proposed as an alternative to antidepressants.

Judith Torrell Diploma in Human Nutrition Clinical Nutrition Specialist