Researchers at Brigham and Women’s Hospital (BWH) have found that sticking to a Mediterranean diet may lead to a longer life. The findings are based on the study of telomeres, the repetitive DNA sequences at the ends of chromosomes. These chromosome tips get shorter every time a cell divides, and their length is a reliable biomarker (biological indicator) of aging in humans. Shorter telomeres have been associated with an increased risk of aging-related diseases (particularly cardiovascular diseases) and a decrease in life expectancy, while longer telomeres, correspondingly, have been linked with longevity.

The researchers hypothesized that telomere shortening, which is accelerated by stress and inflammation, would be hindered by following a Mediterranean diet. This is because the diet features a foundation of fresh plant-based foods – fruits, vegetables, whole grains, and nuts – that are abundant in antioxidants, compounds noted for their anti-inflammatory properties.

To investigate the relationship between lifespan and diet, the researchers compared telomere lengths and food choices in 4,676 disease-free women from the Nurses’ Health Study. The researchers found that a greater adherence to the Mediterranean diet was associated with longer telomeres and that even small changes toward a healthier diet can make a difference.

“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,” explains Immaculata De Vivo, PhD, MPH, an associate professor in the Channing Division of Network Medicine at BWH and Harvard School of Public Health and senior author of the study. “Our results further support the benefits of adherence to this diet to promote health and longevity.”

“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,” adds Marta Crous-Bou, a postdoctoral fellow in the Channing Division of Network Medicine and first author of the study.

The Mediterranean diet has been getting a lot of good press in recent years. It has been linked with a wide variety of health benefits, including a decreased risk of chronic diseases and cancer. Along with a focus on plant-based foods, the diet also includes a relatively high percentage of fat – but a very low percentage of unhealthy fats.

De Vivo suggests that future research should focus on confirming which specific components of the Mediterranean diet are responsible for curbing telomere shortening. With that information in hand, researchers would be able to home in on the biological mechanism(s) at play and enable us to make better-informed dietary choices.