The Mediterranean diet

The Mediterranean diet is a modern nutritional recommendation inspired by the traditional dietary patterns of poor coastal regions of southern Italy, Crete, and Greece in the 1960s.^[1]

Despite its name, this diet is not typical of all Mediterranean cuisine. In Northern Italy, for instance, lard and butter are commonly used in cooking, and olive oil is reserved for dressing salads and cooked vegetables.^[2] In North Africa wine is traditionally avoided by Muslims. In both North Africa and the Levant, along with olive oil, sheep's tail fat and rendered butter (samna) are traditional staple fats.^[3]

The most commonly-understood version of the Mediterranean diet was presented by Dr Walter Willett of Harvard University's School of Public Health in the mid-1990s.^[4] 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.^[5]

The principal aspects of this diet include high olive oil consumption, high consumption of legumes, high consumption of unrefined cereals, high consumption of fruits, high consumption of 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.^[6]

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.^[7] There is also evidence that the antioxidants in olive oil improve cholesterol regulation and LDL cholesterol reduction, and that it has other anti-inflammatory and anti-hypertensive effects.^[8]

 

The diet is often cited as beneficial for being low in saturated fat and high in monounsaturated fat and dietary fiber.^{[citation needed]}

One of the main explanations is thought to be the health effects of olive oil included in the Mediterranean diet.

The Mediterranean diet is high in salt content.^[11] Foods such as olives, salt-cured cheeses, anchovies, capers, salted fish roe, and salads dressed with olive oil all contain high levels of salt.

A study published in the Archives of General Psychiatry shows that people who followed the Mediterranean diet were less likely to develop depression.^[12]

In addition, the consumption of red wine is considered a possible factor, as it contains flavonoids with powerful antioxidant properties.^[13]

Mireille Guiliano credits the health effects of the Mediterranean diet to factors such as small portions, daily exercise, and the emphasis on freshness, balance, and pleasure in food.^[14]

Dietary factors may be only part of the reason for the health benefits enjoyed by these cultures. Genetics, lifestyle (notably heavy physical labor), and environment may also be involved.^{[citation needed]}

A 10-year study published in the Journal of American Medicine found that adherence to a Mediterranean diet and healthful lifestyle was associated with more than a 50% lowering of early death rates.^{[citation needed]}

The putative benefits of the Mediterranean diet for cardiovascular health are primarily correlative in nature; while they reflect a very real disparity in the geographic incidence of heart disease, identifying the causal determinant of this disparity has proven difficult. The most popular dietary candidate, olive oil, has been undermined by a body of experimental evidence that diets enriched in monounsaturated fats such as olive oil are not atheroprotective when compared to diets enriched in either polyunsaturated or even saturated fats.^[15][16] A recently emerging alternative hypothesis to the Mediterranean diet is that differential exposure to solar ultraviolet radiation accounts for the disparity in cardiovascular health between residents of Mediterranean and more northerly countries. The proposed mechanism is solar UVB-induced synthesis of Vitamin D in the oils of the skin, which has been observed to reduce the incidence of coronary heart disease, and which rapidly diminishes with increasing latitude.^[17] Interestingly, residents of the Mediterranean are also observed to have very low rates of skin cancer (which is widely believed to be caused by over-exposure to solar UV radiation); incidence of melanomas in the Mediterranean countries is lower than in Northern Europe and significantly lower than in other tropical countries such as Australia and New Zealand. It's been hypothesized that some components of the Mediterranean diet may provide protection against skin cancer.