The February, 2008 issue of the American Journal of Clinical Nutrition reported the outcome of a Canadian clinical trial which found a beneficial effect for eicosapentaenoic acid (EPA) in middle aged women suffering from psychological distress. Eicosapentaenoic acid is an omega-3 polyunsaturated fatty acid that occurs in fish oil, which, along with docosahexaenoic acid (DHA), has been linked with numerous health benefits.
Michel Lucas and his associates at Laval University in Quebec enrolled 120 women between the ages of 40 and 55 with moderate to severe psychological distress, which can sometimes occur during menopausal transition and early menopause. The group was randomized to receive 1.05 grams ethyl-EPA plus 0.15 grams ethyl-DHA in divided doses, or a placebo daily for eight weeks. Self-rating of symptoms, the Psychological General Well-Being Schedule, and a depression scale symptom check list were completed at the beginning of the study, and at the end of four and eight weeks.
Twenty-four percent of the participants met the criteria of undergoing a major depressive episode. When these women were excluded from the analysis, psychological distress symptoms among those who received EPA were found to have improved significantly after 8 weeks compared to subjects who received the placebo. Women who received a placebo were likelier to drop out of the study than women who received EPA, and although the authors did not consider the amount significant, they remarked that lack of improvement in the placebo group could have increased this likeliness.
In their discussion of possible mechanisms of EPA against psychological distress, the authors note that polyunsaturated fatty acids are needed by brain cell membranes, and that a deficiency of omega-3 fatty acids can impact transmission of serotonin, a neurohormone involved in mood. EPA and DHA have anti-inflammatory and other effects on brain biochemistry, including an ability to alter the expression of enzymes. "To our knowledge, the current trial is the first to compare the effect of ethyl-EPA omega-3 supplementation with placebo on psychological distress and depressive symptoms in middle-aged women," the authors write. "Because EPA and DHA supplements have beneficial outcomes on cardiovascular disease, have no serious side effects, and might be helpful in reducing hot flashes, research should be encouraged in middle-aged women with psychological distress and depressive symptoms."
Related Health Concern: Depression
Depression is considered the most common cause of disability in the United States (Norman TR 2006). According to the National Institutes of Health, clinical depression will affect up to 25 percent of women in their lifetimes and up to 12 percent of men. People with depression suffer in many areas of their lives, including sleep, eating, relationships, school, work, and self-image.
The causes of clinical depression are not fully known. It is likely that several factors, including a genetic predisposition and hormone imbalances, work together in any particular individual to bring on a depressive episode. One of the leading factors associated with depression is reduced levels of norepinephrine, serotonin, and dopamine (the so-called amine theory) (Hou C et al 2006; Prange AJ et al 1974). There is also evidence that the structure of the brain itself may be altered in depression, especially the hippocampus (Campbell S et al 2004), although few studies have been conducted on effective treatment for these changes. Other factors that may contribute to depression include oxidative stress, which can cause cell membrane and DNA destruction in the brain (Khanzode SD et al 2003), inflammation (Elenkov IJ et al 2005), and hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis (Antonijevic IA 2006).
Omega-3 fatty acids are long-chain polyunsaturated fatty acids found in fish and various oils, such as flaxseed or canola oil (Logan AC 2003). The brain has a high concentration of polyunsaturated fatty acids (Yehuda S et al 1999; Bourre JM et al 1991), and depressed people have lower levels of omega-3 fatty acids compared with the pro-inflammatory omega-6 fatty acids (Tiemeier H 2003). Adding the omega-3 fatty acid eicosapentaenoic acid (EPA) to conventional antidepressant treatment relieves depressive symptoms (Puri BK et al 2001). Among children with depression, supplementation with omega-3 fatty acids has shown "highly significant" effects on symptom scores (Nemets H et al 2006). In 2006, researchers analyzed results from six published studies on depression and omega-3 fatty acids. They found that omega-3 fatty acids can reduce symptoms of depression among adults (Williams AL et al 2006).
Omega-3 fatty acids are also beneficial because they reduce the risk of cardiovascular disease, which is highly associated with depression (Burr ML et al 1989; Singh RB et al 1997).