Omega-3 Fatty Acids for Reducing Anxiety and Depression in Adults

I recently wrote about a study that demonstrated that the consumption of omega-3 fatty acids during pregnancy, and after delivery, was associated with a reduced incidence of post-partum depression:

OMEGA-3 FATTY ACIDS REDUCE INCIDENCE OF POST-PARTUM DEPRESSION

In this prior blog post I reviewed what are omega-3 fatty acids (often written as n-3 fatty acids) and what are their health benefits. In addition, for more information I encourage readers to go to my website where the details of omega-3 fatty acids can be found:

Omega-3 & Omega-6 Fatty Acid Synthesis, Metabolism, Functions

Another recent study, published in the scientific journal, Prostaglandins, Leukotrienes, and Essential Fatty Acids, carried out a detailed meta analysis of randomized controlled trials (RCT) on the effects/benefits of omega-3 fatty acids on reducing anxiety and depression in adults:

Effects of long-chain omega-3 polyunsaturated fatty acids on reducing anxiety and/or depression in adults; A systematic review and meta-analysis of randomised controlled trials

Participants in the comparative studies were adults who were 18 years of age for older and for whom there was a validated measure of anxiety and/or depression. The studies excluded pregnant women, patients with lipid-profile altering diseases/conditions (such as type 2 diabetes, polycystic ovary syndrome, liver disease, or hepatitis), and severely unwell patients (such as those with severe injury, cancer diagnosis, dementia).

The study participants had dietary supplementation with any form of long chain omega-3 PUFA comprising EPA with/without DHA and/or DPA with EPA at proportions ≥ 60% of total EPA + DHA administered for ≥ 8 weeks. Results were compared with participants receiving placebo supplementation which was defined as the typical dietary intake of fatty acids of respective countries in which various RCT were conducted, or placebo preparations comprising inert, non-bioactive constituents in relation to the outcome. Typical comparator lipid supplements were soybean oil, coconut oil, sunflower oil, palm oil, canola oil, and paraffin oil.

Studies were excluded from this meta analysis if placebo supplementation comprised bioactive lipids such as olive oil. Olive oil is high in the omega-9 monounsaturated fatty acid (MUFA), oleic acid. A major benefit of oleic acid is its conversion to the appetite suppressing amide, oleoylethanolamide (OEA), by cells of the intestines.

With respect to anxiety the efficacy of EPA alone it was not possible to ascertain due to lack of sufficient RCT for analysis. Nonetheless, one study did show that doses of EPA at 2.1 grams/day (where the amount of EPA was 85.6% of the EPA + DHA total) did exhibit a statistically significant reduction in the severity of anxiety.

With respect to depression the meta analyses were able to identify that there are statistically significant benefits against depression by dietary supplementation with EPA at doses greater than or equal to 1 gram and less than 2 grams per day. The authors indicate that caution should be taken into account when interpreting these findings given that none of the identified RCT studies provided EPA below 1 g/day or above 2.1 g/day.

TAKE HOME: Dietary supplementation with omega-3 polyunsaturated fatty acids (omega-3 PUFA) has long been determined to exert significant benefits to overall health and to reduce the incidence and severity of certain diseases, in particular cardiovascular disease. The role of DHA in early neural development is of such significance that essentially all commercial producers of infant formula now supplement those formulations with DHA. Results from this meta analysis show that the emerging evidence is becoming clear that dietary supplementation with omega-3 PUFA in adults can exert positive benefits on overall mental health.