Objective: To provide an overview of research relevant to the Mediterranean diet.
Design: Personal perspectives.
Subject: Populations in Europe, North America, Asia.
Results: Approximately 50 years ago, Keys and colleagues described strikingly low rates of coronary heart disease in the Mediterranean region, where fat intake was relatively high but largely from olive oil. Subsequent controlled feeding studies have shown that compared to carbohydrate, both monounsaturated and polyunsaturated fats reduce LDL and triglycerides and increase HDL cholesterol. Importantly, these beneficial metabolic effects are greater in the presence of underlying insulin resistance. In a detailed analysis within the Nurses' Health Study, trans fat from partially hydrogenated vegetable oils (absent in traditional Mediterranean diets) was most strongly related to risk of heart disease, and both polyunsaturated and monounsaturated fat were inversely associated with risk. Epidemiologic evidence has also supported beneficial effects of higher intakes of fruits and vegetables, whole grains, fish, and daily consumption of moderate amounts of alcohol. Together with regular physical activity and not smoking, our analyses suggest that over 80% of coronary heart disease, 70% of stroke, and 90% of type 2 diabetes can be avoided by healthy food choices that are consistent with the traditional Mediterranean diet.
Conclusion: Both epidemiologic and metabolic studies suggest that individuals can benefit greatly by adopting elements of Mediterranean diets.