The Mediterranean diet - higher in vegetables, fruits, whole grains and olive oil, and lower in dairy products and meat - has long been cited for its health-promoting benefits. Researchers have new clues as to why.
They found that the diet was associated with longer telomeres, the protective structures at the end of chromosomes. Shorter telomeres are associated with age-related chronic diseases and reduced life expectancy.
Researchers used data on 4,676 healthy women, part of a larger health study, whose diets were ranked on a scale of one to nine for similarity to the ideal Mediterranean diet. Researchers measured their telomere lengths with blood tests and followed them for more than 20 years with periodic examinations.
The study, published in the journal BMJ, controlled for body mass index, smoking, physical activity, reproductive history and other factors, and found that the higher the score for adherence to the diet, the longer the telomeres. The difference in telomere length for each point on the adherence scale was equivalent to an average one-and-a-half years of life.
“Based on our data,” said the lead author, Marta Crous-Bou, a postdoctoral fellow at Harvard Medical School, “a three-point change in the adherence score is equivalent to 4.5 years of aging, a difference comparable to that between smokers and nonsmokers.”