Mediterranean Diet may trim Diabetes Risk

In a study of 418 older Spanish adults, researchers found that those instructed to follow a Mediterranean diet were less likely to develop diabetes over four years than those instructed to follow a low-fat diet -- about 10 percent developed the disease, versus 18 percent in the low-fat group. And weight loss did not appear necessary to gain the benefit.

The findings, reported in the journal Diabetes Care, may sound too good to be true.

But they back up previous work by the same researchers showing that the Mediterranean diet, even without weight loss, appeared to curb the risk of metabolic syndrome -- a collection of risk factors for diabetes that includes abdominal obesity, high blood pressure and elevated blood sugar and triglycerides.

However, even if the eating pattern brings benefits in the absence of weight loss, that does not negate the importance of regular exercise or calorie-consciousness, a spokesperson for the American Dietetic Association told Reuters Health.

Instead, the findings support existing dietary advice for people with diabetes and those at risk of the disease, said Constance Brown-Riggs, a registered dietitian and certified diabetes educator based in Massapequa, New York.

"This pretty much backs up what we've been recommending," Brown-Riggs said.

The traditional Mediterranean diet is generally high in vegetables, fiber-rich grains, legumes, fish and plant-based sources of unsaturated fat -- particularly olive oil and nuts -- while being low in red meat and high-fat dairy, prime sources of saturated fat.

All of those features are healthy choices for anyone, Brown-Riggs pointed out.

But the study, she added, "does not, by any means, say that you don't have to exercise." Nor does it mean that calories are unimportant, she said.

For the study, researchers led by Dr. Jordi Salas-Salvado of the University of Rovira i Virgili in Reus, Spain, followed 418 initially diabetes-free adults between the ages of 55 and 80. Each had at least three risk factors for heart disease, such as high blood pressure, smoking or excess weight.

At the outset, the men and women were randomly assigned to follow one of three diets: a traditional Mediterranean diet with added emphasis on boosting consumption of olive oil, a rich source of monounsaturated fat; the same diet, with a focus on getting polyunsaturated fats from nuts; or a low-fat diet that encouraged cutting down on all types of fat.

In addition, participants in the olive-oil group were given a free allotment of the oil (a liter per week), and those in the nut group were given enough mixed nuts to have about an ounce per day.

None of the groups were told to limit calories or get more exercise.

Over the next four years, the researchers found, 10 percent to 11 percent of participants in the two Mediterranean groups developed diabetes. That compared with 18 percent of those in the low-fat diet group.