Adherence to a Mediterranean diet and glycaemic control in Type 2 diabetes mellitus

Mediterranean-type diets reduce the risk of Type 2 diabetes. Whether a Mediterranean-type diet improves glycaemic control in diabetes remains unknown.

We conducted a cross-sectional analysis in 901 outpatients with Type 2 diabetes attending diabetes clinics located in Campania County, South Italy. We explored the relation between glycated haemoglobin (HbA(1c)), measured centrally, self-measured pre- and postprandial glucose levels and consumption of a Mediterranean-type diet. Adherence to a Mediterranean-type diet was assessed by a 9-point scale that incorporated the salient characteristics of this diet (range of scores, 0-9, with higher scores indicating greater adherence). The study was conducted from 2001 to 2007.

Diabetic patients with the highest scores (6-9) had lower body mass index and waist circumferences, a lower prevalence of the metabolic syndrome and lower HbA(1c) and post-meal glucose levels than diabetic patients with the lowest scores (0-3). In multivariate analysis, mean HbA(1c) and 2-h post-meal glucose concentrations were significantly lower in diabetic patients with high adherence to a Mediterranean-type diet than those with low adherence [difference: HbA(1c) 0.9%, 95% confidence intervals (CI) 0.5-1.2%, P < 0.001; 2-h glucose 2.2 mmol/l, 95% CI 0.8-2.9 mmol/l, P < 0.001].

In Type 2 diabetes, greater adherence to a Mediterranean-type diet is associated with lower HbA(1c) and postprandial glucose levels.