The Mediterranean diet consistently has been linked with an array of health benefits, including decreased risk of chronic disease and cancer. Until now, however, no studies had associated the diet with longer telomeres, one of the biomarkers of aging.

In a study published Tuesday online in The BMJ, researchers at Harvard-affiliated Brigham and Women’s Hospital (BWH) found that greater adherence to the Mediterranean diet correlated with longer telomeres.

Telomeres are repetitive DNA sequences at the ends of chromosomes that get shorter every time a cell divides. Shorter telomeres have been associated with decreased life expectancy and increased risk of aging-related disease, while longer telomeres have been linked to longevity. Telomere shortening is accelerated by stress and inflammation, and scientists have speculated that adherence to the Mediterranean diet may help protect against that effect.

“To our knowledge this is the largest population-based study specifically addressing the association between Mediterranean diet adherence and telomere length in healthy, middle-aged women,” explained Immaculata De Vivo, an associate professor in the Channing Division of Network Medicine at BWH and the Harvard T.H. Chan School of Public Health, the senior author of this study. “Our results further support the benefits of adherence to this diet to promote health and longevity.”

The researchers analyzed 4,676 disease-free women from the Nurses’ Health Study who had completed the food-frequency questionnaire and whose telomere lengths had been measured. They found that a greater adherence to the Mediterranean diet was associated with longer telomeres, and that even small changes in diet made a difference.

“Our findings showed that healthy eating, overall, was associated with longer telomeres. However, the strongest association was observed among women who adhered to the Mediterranean diet,” explained Marta Crous Bou, a postdoctoral fellow in the Channing Division of Network Medicine and the first author of the study.

De Vivo notes that future research should be aimed at determining which components of the Mediterranean diet drive this association. This would allow researchers to gain insight into the biological mechanism, as well as provide a basis for increased public education for informed lifestyle choices.