A Mediterranean diet enriched with extra virgin olive oil but without calorie restrictions reduced diabetes risk among persons with high cardiovascular risk, a study found.
Researchers in Spain reviewed primary prevention of diabetes in a multicenter, randomized trial from October 2003 to December 2010 (median follow-up, 4.1 years) more than 3,500 adults ages 55 to 80 without diabetes and at high cardiovascular risk.
Participants were randomly assigned 1:1:1 and stratified by site, sex and age but not diabetes status to receive either a Mediterranean diet supplemented with extra-virgin olive oil, a Mediterranean diet supplemented with nuts, or a control diet consisting of advice on a low-fat diet. There were no steps taken to increase physical activity or lose weight.
Results appeared in the Jan. 7 issue of Annals of Internal Medicine.
New-onset cases of diabetes occurred in the Mediterranean diet supplemented with extra virgin olive oil (80; 16 cases per 1,000 person years), in the Mediterranean diet supplemented with mixed nuts (92; cases per 1,000 person years), and control diet groups (101; cases per 1,000 person years).
Multivariate-adjusted hazard ratios were 0.60 (95% CI, 0.43 to 0.85) for the Mediterranean diet supplemented with extra virgin olive oil and 0.82 (CI, 0.61 to 1.10) for the Mediterranean diet supplemented with nuts compared with the control diet.
Researchers concluded that the trial “provides strong evidence that long-term adherence to a Mediterranean diet supplemented with [extra virgin olive oil] without energy restrictions, which is high in monounsaturated fat and bioactive polyphenols, results in a substantial reduction in the risk for type 2 diabetes among older persons with high cardiovascular risk. Of note, this dietary pattern is palatable and has a high potential for long-term sustainability, with obvious public health implications for primary prevention of diabetes.”