Clinical Newswire, Jan 22 - Patients with coronary heart disease who have higher levels of omega-3 fatty acids in their blood also have an associated lower rate of telomere shortening, a chromosome marker for cellular aging, pointing to a possibility that these fatty acids may protect against biologic aging, according to study results published in the January 20 issue of the Journal of the American Medical Association (JAMA).
Numerous studies, including several large randomized controlled trials, have shown that individuals with established cardiovascular disease who have high dietary intake of marine omega-3 fatty acids have higher survival rates. The mechanisms underlying this protective effect are not well understood.
Telomeres are DNA sequences forming a protective cap at the end of a chromosome. They are involved in the replication and stability of a chromosome. Cumulative loss of telomere length during cell replication, as well as due to environmental stressors, may eventually result in cellular aging and apoptosis. Therefore telomere length has emerged as a novel marker for biological age, and in particular, a robust association has been shown between short telomeres and cardiovascular morbidity and mortality.
Ramin Farzaneh-Far, MD (University of California, San Francisco) and colleagues conducted a prospective cohort study to determine whether omega-3 fatty acid blood levels were associated with changes in leukocyte telomere length in patients with stable coronary artery disease. The study involved 608 ambulatory outpatients recruited from the Heart and Soul Study between September 2000 and December 2002, and followed up to January 2009 for a median of 6 years. Leukocyte telomere length was measured at the beginning of the study and again after 5 years of follow-up. Multivariate models were used to examine the association of baseline levels of marine omega-3 fatty acids - docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), with subsequent change in telomere length.
The researchers found that individuals in the lowest quartile of omega-3 fatty acid level had the fastest rate of telomere shortening over 5 years, while those in the highest quartile experienced the slowest rate of telomere shortening. “Each 1-SD (standard deviation) increase in baseline omega-3 fatty acid levels was associated with a 32% decrease in the odds of telomere shortening,” the authors write. No evidence was found that the effect of baseline omega-3 fatty acid levels on telomere length was modified by age, sex, race or ethnicity, smoking, income, education, or type 2 diabetes, however, the protective effects of baseline omega-3 fatty acids on telomeric aging was more pronounced in individuals with longer baseline telomeric length.
Although the level of omega-3 fatty acids is only one of the many factors influencing telomere length in the patient sample studied, and further studies are needed to understand the complex integration of influences on telomere length, “among patients with stable coronary artery disease, there was an inverse relationship between baseline blood levels of marine omega-3 fatty acids and the rate of telomere shortening over 5 years”, the researchers conclude.
These findings raise the possibility that marine omega-3 fatty acids may have protective effect against cellular aging in patients with coronary heart disease.
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