February 2010

A new study suggests high blood levels of omega-3 fatty acids may slow cellular aging in people with coronary heart disease.

Researchers from the University of California, San Francisco (UCSF), looked at the length of telomeres � DNA sequences at the end of chromosomes that shorten as cells replicate and age.

The aging and lifespan of normal, healthy cells are linked to the telomere shortening mechanism, which limits cells to a fixed number of divisions. Some experts have noted that telomere length may be a marker of biological aging. With each replication the telomeres shorten, and when the telomeres are totally consumed, the cells are destroyed.

" 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 five years," wrote the researchers, led by Ramin Farzaneh-Far. " These findings raise the possibility that omega-3 fatty acids may protect against cellular aging in patients with coronary heart disease," they added.

The UCSF researchers looked at telomere length in blood cells of 608 outpatients with stable coronary artery disease. The length of telomeres was measured in leukocytes (white blood cells) at the start of the study and again after five years.

Comparing levels of omega-3 fatty acids, EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) with subsequent change in telomere length, the researchers found that individuals with the lowest average levels of DHA and EPA experienced the most rapid rate of telomere shortening, while people with the highest average blood levels experienced the slowest rate of telomere shortening.
" Each 1-standard deviation increase in DHA, plus EPA levels was associated with a 32% reduction in the odds of telomere shortening," wrote the authors.

Commenting on the potential mechanism, Dr. Farzaneh-Far and his co-workers noted that this may be linked to oxidative stress, known to drive telomere shortening. Omega-3 fatty acids have been shown to reduce levels of F2-isoprostanes, markers of systemic oxidative stress, as well as increasing levels of the antioxidant enzymes catalase and superoxide dismutase, thereby reducing oxidative stress.

The researchers added that a double-blind, randomized, placebo-controlled trial would be necessary to definitively confirm the link between omega-3 fatty acids and cellular aging.

Journal of the American Medical Association 303(3):250-257, 2010