According to the authors of this study published this week in The British Medical Journal, diet has long been known to be an important risk factor for the development of type 2 diabetes. And there is evidence that the so-called Mediterranean diet reduces the risk of cardiovascular disease. Martínez-González and colleagues, from Spain, looked at the relationship between adhering to a Mediterranean diet and the incidence of diabetes among more than 13 000 Spanish undergraduates without diabetes at the start of the study and followed them up for 4.4 years.
The major protective characteristics of the Mediterranean diet include a high intake of fibre, a high intake of vegetable fat, a low intake of trans fatty acids, and a moderate intake of alcohol. A particular feature of the diet is the abundant use of virgin olive oil for cooking, frying, spreading on bread, or dressing salads. This leads to a high ratio of monounsaturated fatty acids to saturated fatty acids. This ratio can be used to score adherence to a Mediterranean diet as the traditional diet. Despite having a relatively high total fat content, this food pattern is rich in monounsaturated fatty acids (from olive oil) and poor in saturated fatty acids. 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.
The study found that those who stuck closely to the traditional Mediterranean diet reduced their risk of developing type 2 diabetes significantly. The study also found that, among the participants who had the highest initial risk of type 2 diabetes, the diet had the greatest effect, suggesting that this eating pattern has significant potential for preventing the onset of the disease.
