The research suggests but doesn’t conclusively prove that the diet lowers or even eliminates the extra risk of stroke, perhaps by lowering the rate of diabetes. Still, “our work has placed a solid step on the ladder of personalized nutrition and successful health,” said study co-author Jose Ordovas, director of the nutrition and genomics laboratory at Tufts University’s USDA Human Nutrition Research Center on Aging.
The so-called Mediterranean diet is thought to help citizens of Greece, Spain and southern Italy lower their rates of heart disease and cancer. While the diet has received tremendous attention in recent years, there’s no firm definition of what it is because foods vary from region to region.
The Mediterranean diet is generally defined, however, as emphasizing olive oil, nuts, fresh produce and fish along with whole grains, seeds and healthier kinds of fat. There’s less focus on dairy products and meat, and — despite the Italian connection — not much consumption of pasta.
Some of the participants had a genetic trait in common: a mutation in a gene that boosts the risk of type 2 diabetes by as much as 50 percent compared to others with another form of the gene. Ordovas said that about 30 percent of whites have the riskiest form of the mutation.
Those with the mutation who went on the low-fat diet were nearly three times more likely than others to have a stroke, the investigators found. But those who went on the Mediterranean diets had about an equal level of risk as those without the genetic mutation.
The percentage of people in the various groups who suffered strokes ranged from 1.4 percent to 4.3 percent, Ordovas said.