Low EPA linked to depression, and omega-3 and DHA shown to help symptoms of Alzheimers disease, in four new studies.
In a depression study, researchers measured blood levels of eicosapentaenoic acid (EPA) in about 1,400 men and women with an average age of 75 and symptoms of depression and compared results to a matching group of healthy adults. Those with depressive symptoms averaged 16 percent lower EPA levels than healthy adults and among those taking antidepressants, the higher the level of EPA, the less severe the depression.
In a related study, researchers measured blood levels of EPA and other fatty acids in about 1,200 healthy participants. After four years, doctors found that the 65 who had developed mental decline (dementia) had lower EPA levels than those who remained healthy. Doctors noted that those who had too much omega-6 compared to omega-3 were more likely to develop dementia, particularly those who also had symptoms of depression.
In an Alzheimer’s disease (AD) study, 23 participants with mild or moderate AD and 23 participants with mild mental decline took 1,800 mg of fish oil per day or a placebo. After 24 weeks, those who had taken omega-3 had better mood, mental clarity, judgment, and physical control compared to placebo. Those with mild mental decline who took omega-3 also scored better in a test for AD than those in the placebo group. Doctors observed that as EPA on red blood cell membranes increased, mental condition improved.
In another AD study, researchers measured blood levels of nutrients in 36 participants with AD. Those with moderately severe AD had much lower levels of the carotenoid antioxidants lutein and beta-carotene compared to those with mild AD. Participants with lower levels of lutein, beta-carotene and docosahexaenoic acid (DHA), and higher levels of LDL cholesterol scored lower on recall, math, attention and language skills than those with healthier levels.
Reference: Neuro-Psychopharmacology & Biological Psychiatry; 2008, Vol. 32, No. 6, 1538-44.