Omega-3 Fatty Acids: Good For The Heart, And (maybe) Good For The Brain

"Given recent findings of serious risks linked with antidepressants, we should prioritize the study of natural antidepressants contained in dietary sources -- specifically, omega-3 fatty acids, found most abundantly in fish and seafood," says Dr. Barbara Levine, associate professor of nutrition in clinical medicine at Weill Cornell Medical College and director of the DHA Information Center at NewYork-Presbyterian/Weill Cornell. Dr. Levine has been studying DHA (docosahexaenoic acid -- a component of omega-3s) and its effects on lowering triglycerides and raising HDL (high-density lipoproteins) in overweight and obese patients with metabolic syndrome.

"Omega-3 consumption in the U.S. is lower than in any other country; the U.S. also has one of the highest depression rates in the world," says Dr. Jeffrey Borer, chief of the division of cardiovascular pathophysiology at NewYork-Presbyterian/Weill Cornell and Gladys & Roland Harriman Professor of Cardiovascular Medicine at Weill Cornell Medical College. "New research has linked omega-3 consumption inversely with incidence of neurological and immune disorders. However, further research among all age groups and populations is necessary in order to confirm these findings and to further educate the public."

The relation of omega-3s -- principally DHA and EPA (eicosapentaenoic acid) -- and depression has been revealed in several studies worldwide. In a large Finnish study of fish consumption and depressive symptoms, published in Psychiatric Services in April 2001, Tanskanen, et al. demonstrated that the likelihood of having depressive symptoms was significantly higher among infrequent fish consumers than among frequent fish consumers. They theorized that the human brain is adapted to Paleolithic diets of our ancient ancestors, whose diet comprised equal proportions of omega-3 fatty acids and omega-6 fats (found in corn and soy seed oils). In the past 100 years, Western diets have lowered the ratio of omega-3 to omega-6 to about 1:25; simultaneously, the prevalence of major depression has increased.

In the 2003 Rotterdam Study, published in the American Journal of Clinical Nutrition, Tiemeir, et al. found that elderly persons with depression had a fatty acid composition different from that of non-depressed persons. Percentages of omega-3 polyunsaturated fatty acids (PUFAs) were significantly lower, and the ratios of omega-6 to omega-3 PUFAs were significantly higher in subjects with depressive disorders than in control subjects.

Dr. Joseph R. Hibbeln of the National Institute on Alcohol Abuse and Alcoholism, part of the National Institutes of Health (NIH), discovered that omega-3 may influence serotonin functionality in the brain. In a letter published in The Lancet in April 1998, he reported that among healthy volunteers, low plasma concentrations of DHA predict low concentrations of a marker of brain serotonin turnover. Low concentrations of serotonin are strongly associated with depression and suicide.

DHA is a primary building block in the gray matter of the human brain and in the retina of the eye, and is present in every cell in the body. It is essential at every stage of human life, beginning in utero. DHA, like EPA, must be derived from foods because the body cannot produce its own supply. It is available in fish and as a pure pharmaceutical-grade nutritional supplement, with an ideal ratio of omega-3s to omega-6s (10:1).

At the Food and Drug Administration's Psychopharmacologic Drugs and Pediatric Advisory Committees meeting on Sept. 13 and 14, committee members and relatives of children with depression heard testimony based on an analysis by an international panel of pediatric suicide experts of data from 15 clinical studies on the use of SSRI (Selective Serotonin Reuptake Inhibitor) antidepressants in children and teens with major depressive disorder (MDD). They also heard from industry representatives of the companies who manufacture the medications. Dr. Tarek Hammad, a Senior Medical Reviewer in the Department of Neuropharmacological Drug Products, Center for Drug Evaluation and Research, Food and Drug Administration, reported that there was a consistent link between antidepressants and suicidal thoughts and behavior (suicidality) among 2 to 3 percent of the subjects in the studies.

As a result of the hearings and recommendations by the joint committees, on Friday, Oct. 15, the FDA announced that it will direct manufacturers to add a "black box" warning to the health professional labeling of all SSRI antidepressant medications to describe this risk and emphasize the need for close monitoring of patients started on these medications. The FDA will also develop a Patient Medication Guide (MedGuide), which will be given to patients receiving the drugs to advise them of the risk and precautions that should be taken.