The traditional Mediterranean diet has long been associated with lower risk of developing cardiovascular disease, cancer, and dementia. The diet is rich in olive oil, fruits, nuts, cereals, vegetables, and fish but relatively low in dairy products and meat. Several studies suggest the Mediterranean diet may also help prevent type 2 diabetes.
Researchers at the University of Navarra in Spain followed 13,380 non-diabetic university graduates, many of them health professionals, over the course of 4.4 years. Average age was 38. I assume most of the study participants lived in Spain, if not elsewhere in Europe (the article doesn’t say). Dietary habits were assessed at the start of the study with a food frequency questionnaire. Food intake for each participant was scored by adherence to the traditional Mediterranean diet. Participants were labelled as either low, moderate, or high in adherence. Over an average follow-up of 4.4 years, 33 of the study participants developed type 2 diabetes. Compared to the participants who scored low on adherence to the Mediterranean diet, those in the high adherence category had an 83% lower risk of developing diabetes. The moderate adherence group also had diminished risk, 59% less.
How could the Mediterranean diet protect against diabetes? The authors note several potential mechanisms: high intake of fiber, low amounts of trans fats, moderate alcohol intake, high vegetable fat intake, and high intake of monounsaturated fats relative to saturated fats. Olive oil, loaded with monounsaturated fats, is the predominant fat in the Mediterranean diet. In summary from the authors:
Diets rich in monounsaturated fatty acids improve lipid profiles and glycaemic control in people with diabetes, suggesting that a high intake improves insulin sensitivity. Together these associations suggest the hypothesis that following an overall pattern of Mediterranean diet can protect against diabetes. In addition to having a long tradition of use without evidence of harm, a Mediterranean diet is highly palatable, and people are likely to comply with it.
Please give serious consideration to the Mediterranean diet, especially if you are at risk for developing type 2 diabetes. Major risk factors include sedentary lifestyle, overweight, and family history of diabetes.
Steve Parker, M.D.
Reference: Martinez-Gonzalez, M.A., et al. Adherence to Mediterranean diet and risk of developing diabetes: prospective cohort study. British Medical Journal, BMJ,doi:10.1136/bmj.39561.501007.BE (published online May 29, 2008).