Mediterranean Diet- Myth or Substance?

Mediterranean diet is a term applied to a dietary pattern based on the traditional diet of the region encompassing southern Italy, Greece (notably the Greek island of Crete) and parts of the Middle East.

The most common version of the Mediterranean diet was presented, amongst others, by Dr Walter Willett of Harvard University in the mid-1990s. Based on “food patterns typical of Crete, much of the rest of Greece, and southern Italy in the early 1960s”, this diet, in addition to “regular physical activity,” emphasizes “abundant plant foods, fresh fruit as the typical daily dessert, olive oil as the principal source of fat, dairy products (principally cheese and yogurt), and fish and poultry consumed in low to moderate amounts, zero to four eggs consumed weekly, red meat consumed in low amounts, and wine consumed in low to moderate amounts”.

Total fat in this diet is 25% to 35% of calories, with saturated fat at 8% or less of calories. The principal aspects of this diet include high olive oil consumption, high consumption of legumes, unrefined cereals, fruits, vegetables, moderate consumption of dairy products (mostly as cheese and yogurt), moderate to high consumption of fish, low consumption of meat and meat products, and moderate wine consumption. Olive oil is particularly characteristic of the Mediterranean diet. It contains a very high level of monounsaturated fats, most notably oleic acid, which epidemiological studies suggest may be linked to a reduction in coronary heart disease risk. There is also evidence that the antioxidants in olive oil enhance LDL cholesterol (the so-called “bad” cholesterol) metabolism, and that it has anti-inflammatory and anti-hypertensive effects.

The Mediterranean diet throws up an interesting paradox: that populations consuming it have a lower incidence of Coronary Artery Disease (CAD) in spite of consuming relatively higher amounts of fat than places like the US where similar amounts of fat consumption are seen. The beneficial effects accrue from the low levels of saturated fat and high levels of monounsaturated fat and dietary fiber. One main reason for this fat distribution pattern is the significant presence of olive oil. The inclusion of red wine is considered a factor contributing to health as it contains flavonoids with powerful antioxidant properties. A number of international studies have attempted to validate the positive health effects of the Mediterranean diet.

The Seven Countries Study found that men from Crete island had exceptionally low death rates from heart disease, despite moderate to high intake of fat. The Cretan diet is similar to other traditional Mediterranean diets, consisting mostly of olive oil, bread, abundant fruit and vegetables, fish, and a moderate amount of dairy foods and wine. According to a 2008 study published in the British Medical Journal, the traditional Mediterranean diet provides substantial protection against type 2 diabetes. A 2008 study published in The New England Journal of Medicine examined the effects of three diets: low-carbohydrate, low-fat, and Mediterranean.

The study involved 322 participants and lasted for two years. The low-carb and Mediterranean diet resulted in the greatest weight loss, 12 lbs and 10 lbs, respectively. The low-fat diet resulted in a loss of 7 lbs. One caveat of the study is that 86% of the study participants were men. The low-carb and Mediterranean diets produced similar amounts of weight loss in the overall study results and in the men. In the remaining participants who were women, the Mediterranean diet produced 3.8 kg (8.4 lbs) more weight loss on average than the low-carb diet. A study published in the British Medical Journal in 2009 showed some components of the Mediterranean diet, such as high vegetable consumption and low meat and meat product consumption, are more significantly associated with low risk of mortality than other components, such as cereal consumption and fish consumption.

A 2011 meta-analysis published in the Journal of the American College of Cardiology analyzed the results of 50 studies covering about 535,000 people to examine the effect of a Mediterranean diet on metabolic syndrome. The researchers reported that a Mediterranean diet is associated with lower blood pressure, blood sugar and triglycerides.

Such a diet may be difficult to adopt in our Indian milieu, but the broad composition and distribution of various components could serve as a template for a healthier, heart-friendly diet, given the soaring incidence of Coronary Artery Disease and diabetes in our country.