| Researchers at the University of California, San Francisco reveal in the January 20, 2010 issue of the Journal of the American Medical Association (JAMA) that heart disease patients who have higher levels of omega-3 fatty acids experience a lower rate of reduction in telomere length over time. Telomeres, which are protective DNA sequences at the ends of chromosomes, shorten with the age of the cell, and their length is a marker of biological aging. In their introduction to the article, Ramin Farzaneh-Far, MD and colleagues note that "Multiple epidemiologic studies, including several large randomized controlled trials, have demonstrated higher survival rates among individuals with high dietary intake of marine omega-3 fatty acids and established cardiovascular disease. On this basis, the American Heart Association recommends increased oily fish intake and the use of omega-3 fatty acid supplements for the primary and secondary prevention of coronary heart disease. The mechanisms underlying this protective effect are poorly understood but are thought to include anti-inflammatory, antiplatelet, antihypertensive, antiarrhythmic, and triglyceride-lowering effects." The current investigation enrolled 608 men and women recruited from the Heart and Soul Study, which assessed the effect of psychosocial factors on cardiovascular events in patients with stable coronary artery disease. Blood samples obtained upon enrollment between September, 2000 and December, 2002 were analyzed for levels of the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in addition to other factors. White blood cell telomere length was measured at the beginning of the study and after 5 years of follow up. Patients whose levels of EPA and DHA were among the top 25 percent of participants had the slowest rate of telomere shortening over the 5 year period, while those whose levels were lowest had rates that were the fastest. The authors noted that "Each 1-standard deviation increase in DHA + EPA levels was associated with a 32 percent reduction in the odds of telomere shortening." In their discussion of the finding, Dr Farzaneh-Far and colleagues remark that several studies had observed cross-sectional associations between longer telomeres and nutritional supplements, including folic acid, multivitamins and vitamins C, D and E, however, these studies lacked longitudinal data on telomere shortening rates. Because increased oxidative stress has been identified as a factor in telomere shortening and aging, the ability of omega-3 fatty acids to help reduce oxidative stress as previously determined by lower levels of F2-isoprostanes and higher levels of the body's antioxidant enzymes in response to supplementation could explain the benefit observed in the current research. Additionally, the authors speculate that omega-3 fatty acids could enhance the activity of telomerase (the enzyme that helps maintain telomere length) in healthy tissue, while suppressing it in cancer cells. "In this longitudinal study, we observed that baseline levels of marine omega-3 fatty acids were associated with decelerated telomere attrition over 5 years," the authors conclude. "These findings raise the possibility that omega-3 fatty acids may protect against cellular aging in patients with coronary heart disease." |
