A new study finds that following the Mediterranean diet could add about 4.5 years to your life. Researchers found that the diet, which focuses on fruits, veggies, whole grains, and olive oil, is good for our DNA, the New York Times reports. Nearly 4,700 women were followed for more than 20 years, and those whose diets were more similar to the Mediterranean diet had longer telomeres—protective structures found on the ends of chromosomes that "are often compared to the plastic caps that prevent shoelaces from unravelling," as Larry Husten explains at Forbes. Shorter telomeres have been linked to shorter life expectancy and chronic diseases associated with aging.
Chromosomes store our DNA code, and telomeres help to prevent the loss of genetic information—so the Mediterranean diet appears to "stop our DNA code from scrambling as we age," thus keeping us "genetically younger," writes Michelle Roberts at the BBC. But Husten cautions that, though the diet has been linked to other health benefits in the past, this study shouldn't be given too much weight. It appears to be "excellent" and "well-performed," he writes, but it was an observational study, and as such has limitations—for example, it's possible that there were already genetic differences between subjects who adhered to the diet and those who didn't.