Dr. Jacques of Tufts University, Boston, and colleagues, evaluated the prospective association between a Mediterranean-style diet pattern and the traits and incidence of the metabolic syndrome in non-diabetic participants of the Framingham Heart Study Offspring Cohort.

The longitudinal association between the Mediterranean-style diet pattern score (MSDPS) and the traits and incidence of the metabolic syndrome was examined among 2,730 and 1,918 participants, respectively. At baseline, none of the subjects had type 2 diabetes, the average age was 54 years, and 55% were women.

Metabolic syndrome traits included abnormal homeostasis model assessment-insulin resistance (HOMA-IR), fasting plasma glucose, waist circumference, plasma triglycerides, high density lipoprotein (HDL) cholesterol, and systolic and diastolic blood pressure. The National Cholesterol Education Program Adult Treatment Panel III definition was used to assess the incidence of the metabolic syndrome. The patients were followed for a mean of 7 years.

After adjustment for corresponding baseline values and for several risk factors associated with type 2 diabetes, individuals with a higher MSDPS had significantly lower HOMA-IR (p = 0.02), fasting glucose (p = 0.03), waist circumference (p < 0.001), and triglyceride levels (p < 0.001).

Those with a higher MSDPS had higher HDL cholesterol (p = 0.02), but no association was seen between blood pressure and MSDPS.

After adjusting for BMI, age, sex, smoking and energy intake, the incidence of metabolic syndrome was significantly lower in participants who fell into the highest quintile category of the MSDPS compared with those in the lowest quintile category (30.1% versus 38.5%, respectively; p = 0.01).

"The potential advantages of this dietary pattern, relative to other recommendations, include the well-defined nature of the overall diet pattern and its palatability," Dr. Jacques commented.

While evidence of the potential health benefits of the Mediterranean-style diet is accumulating, "we need to be cautious in interpreting these findings until we can clearly demonstrate that it is the diet itself that is responsible for the observed benefits," he added, "and that these associations are not just a consequence of individuals who consume such a diet making healthier lifestyles choices over and above their diet."