A new study from Spain attempts to assess the relation between adherence to a Mediterranean diet and the incidence of diabetes among initially healthy participants. Estimates of relative risk were adjusted for sex, age, years of university education, total energy intake, body mass index, physical activity, sedentary habits, smoking, family history of diabetes, and personal history of hypertension. Participants were 13,380 Spanish university graduates without diabetes at baseline who were followed up for 4.4 years.
The Dietary habits were assessed at baseline with a validated 136 item food frequency questionnaire (such as legumes, olive oil, dairy, red meat, alcohol intake) which was scored on a nine point index. New cases of diabetes confirmed through medical reports and an additional detailed questionnaire posted to those who self reported a new diagnosis of diabetes by a doctor during follow-up. There were 33 confirmed cases of type 2 diabetes.
The study found that participants who adhered closely to a Mediterranean diet had a lower risk of diabetes. The incidence rate ratios adjusted for sex and age were 0.41 (95% confidence interval 0.19 to 0.87) for those with moderate adherence (score 3-6) and 0.17 (0.04 to 0.75) for those with the highest adherence (score 7-9) compared with those with low adherence (score <3). In the fully adjusted analyses the results were similar. A two point increase in the score was associated with a 35% relative reduction in the risk of diabetes (incidence rate ratio 0.65, 0.44 to 0.95), ie even adhering to a few elements of the Mediterranean diet reduces the risk of late onset diabetes.
Professor R. Curtis Ellison comments:
Certainly, the high-scorers on the Mediterranean Diet drank a little more alcohol, but they had even more striking differences in many other aspects of diet. While the study supports earlier work of Trichopolou and the Harvard studies, there were only 33 cases of diabetes in this cohort of over 13,000 Spaniards and therefore it cannot add very much to current findings. Live a healthy lifestyle and do not get fat, and you have much lower risk of diabetes.
Source: BMJ, doi: 10.1136/bmj.39561.501007.BE, Research Adherence to Mediterranean diet and risk of developing diabetes: prospective cohort study