Eat Fish to Beat the Blues

Healthnotes Newswire (September 20, 2007)—You may have heard the rumors that taking fish oil can help you avoid depression. A new review of the research found that it may indeed be a key to a better mood.

Depression is one of the leading causes of disability in the world. Its incidence varies greatly between countries, and one explanation might be the amount of fish that people eat. Researchers have observed that in places where fish features more prominently in the diet, the incidence of depression is lower.

Cold water fish, such as tuna, salmon, herring, and mackerel, contain two important omega-3 fatty acids: EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Because these fatty acids are highly unsaturated, they stay liquid at cold temperatures, allowing the fish to remain flexible in very cold waters. When eaten by humans, these fatty acids instill flexibility in cell membranes throughout the body and change cell activity and interaction in ways that are not yet fully understood.

Some of the health benefits observed in people with high omega-3 fatty acid intake from fish include reduced inflammation, reversal of abnormal heart rhythms, lower blood pressure and triglyceride levels, and lower risk of sudden cardiac death and some cancers. Studies have found lower levels of omega-3 fatty acids in depressed people than in people without depression, and a few studies have found that supplementing with omega-3 fatty acids may be an effective treatment.

The authors of the new report examined ten studies comparing the effects of omega-3 fatty acids with placebo on depression. The studies all lasted four or more weeks and included at least 20 people. The analysis included a total of 327 participants who took from 1 to 9.6 grams of omega-3 fatty acids per day. After analyzing the pooled data, the authors found a significant antidepressant effect for omega-3 fatty acids.

“We found that omega-3 polyunsaturated fatty acids significantly improved depressive symptoms in people with mood disorders, with clearly defined depression, or with bipolar disorder,” the researchers said. They noted that the effect was more pronounced in people using 4 grams or more of EPA per day than in people using 2 grams or less. The amount of DHA used did not change the effectiveness, and DHA alone has not shown any antidepressant effect.

The study’s authors went on to suggest that the safety and other health benefits of fish oil and omega-3 fatty acids make them useful in a wide range of people with depression.

“Recently, there is increasing interest in the use of omega-3 polyunsaturated fatty acids for the treatment of depressive disorders, especially in those difficult-to-treat populations such as patients with postpartum depression, childhood depression, and treatment-resistant depression. As depression is frequently associated with coronary heart disease, diabetes mellitus, and pregnancy and breast-feeding, the safety of omega-3 fatty acids should also benefit the physical state of these patients.”

(J Clin Psychiatry 2007;68:1056–61)

Maureen Williams, ND, received her bachelor’s degree from the University of Pennsylvania and her Doctorate of Naturopathic Medicine from Bastyr University in Seattle, WA. She has a private practice in Quechee, VT, and does extensive work with traditional herbal medicine in Guatemala and Honduras. Dr. Williams is a regular contributor to Healthnotes Newswire.

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