MADRID, SPAIN — A Mediterranean diet enriched with extra-virgin olive oil led to reduced diabetes risk among people with high cardiovascular risk, according to a subgroup analysis of a randomized trial in Spain that appeared on-line Jan. 7 in the Annals of Internal Medicine. The study involved 3,541 people of the ages 55 to 80 years who, upon entering the study, had high cardiovascular risk but no diabetes.

The people were part of the Prevención con Dieta Mediterránea trial from October 2003 to December 2010. Median follow-up was 4.1 years. The setting was primary care centers in Spain.

Researchers divided people randomly to receive one of three diets: the Mediterranean diet supplemented with extra-virgin olive oil, the Mediterranean diet supplemented with nuts or a control diet that included advice on a low-fat diet.

During follow-up, 80 people on the diet with extra-virgin olive oil developed new-onset cases of diabetes. The numbers were 92 for the diet with nuts and 101 for the control diet. Multivariate-adjusted hazard ratios were 0.6 for the diet with extra-virgin olive oil and 0.82 for the diet supplemented with nuts.