Diet, Mediterranean

Related Terms

Antioxidants, caffeic acid, diet, fruit and vegetable diet, fatty acids, good fat diet, Greek diet, high fat diet, Italian diet, olive oil, omega-3 fatty acids, tyrosol, vegetarian, vegetarian diet, wine.

Background

The Mediterranean diet is rich in heart-healthy fiber and nutrients including omega-3 fatty acids and antioxidants. The diet generally includes: fruits, vegetables and unsaturated "good" fats, particularly olive oil. Olive oil has been associated with benefits such as lower blood pressure and a lower risk for heart disease. In addition, olive oil may benefit people with type 2 diabetes.
The Mediterranean diet is based on the healthy eating and lifestyle habits of the people living in southern Italy, the Greek island of Crete and other areas of Greece in the early 1960s.
The diet has become a popular area of study due to observations made in the 1960s of low incidences of chronic diseases, such as heart disease and high cholesterol. Additionally, high life-expectancy rates exist among populations who consumed a traditional Mediterranean diet. Therefore, the Mediterranean diet gained much recognition and worldwide interest in the 1990s as a model for healthful eating.
Proponents claim that the Mediterranean diet can be use to decrease the risk of heart-related problems such as high blood pressure, high cholesterol, heart attacks, and Alzheimer's disease.

Theory / Evidence

Olive oil, the main fatty component of the Mediterranean diet, is characterized by monounsaturated fatty acids as well as by its elevated content of antioxidant agents. An antioxidant is thought to protect the body's cells from the damaging effects of oxidation by scavenging for free radicals (highly reactive molecules that attack cells in the body) generated during the metabolic processes of the body. The high portion of monounsaturated fatty acids in olive oil may cause a decrease in LDL (bad) cholesterol and an increase in HDL (good) cholesterol, which may diminish the risk of suffering from heart troubles. The antioxidants present in olive oil are thought to scavenge for free radicals, which are highly reactive molecules that attack cells in the body. The antioxidants may also protect against peroxidation or further cell damage by free radicals. Although there have been several studies linking olive oil consumption to cholesterol regulation and free radical scavenging in humans, animal studies have suggested that fats (olive oil) in the Mediterranean diet may harm blood vessels. Thus, there is still controversy over the safety and efficacy of olive oil and its role in the Mediterranean diet.
Wine and olive oil, essential components of the Mediterranean diet, are considered important additions to a healthy lifestyle because of their tyrosol and caffeic acid content. Tyrosol is a substance that may help prevent "bad" cholesterol. And, studies have suggested that caffeic acid may have antimitogenic, anticarcinogenic, anti-inflammatory and immunomodulatory properties.
A number of cancers, such as cancer of the large bowel and breast, are less frequent in Mediterranean countries than in northern Europe. It has been hypothesized that a low dietary intake of saturated fat accompanied by a higher intake of unrefined carbohydrates and possibly other protective nutrients could be the cause of such risk differences. Cohort and case control studies based on individual dietary intake, however, cannot definitely confirm or dispute the theory. Analytical studies on fat, fiber and breast and colon cancers are being reviewed.
Based on several clinical studies, benefits of this diet may take between four weeks to two years to occur.

Author information

This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography

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Bellati U, Pompa P, and Liberati M. [Analytic evaluation of a "Mediterranean" diet in pregnancy]. Minerva Ginecol. 1994;46(4):183-187.
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Bertelli AA, Migliori M, Panichi V, et al. Oxidative stress and inflammatory reaction modulation by white wine.
de la Lastra A, Barranco MD, Motilva V, et al. Mediterranean diet and health: biological importance of olive oil. Curr.Pharm.Des 2001;7(10):933-950.
de Lorgeril, M. "The Mediterranean-style diet". Is it ideal for the modern world? Asia Pac.J.Clin.Nutr. 2004;13(Suppl):S18.
Women's Heart Foundation.

Diet outline

The common Mediterranean diet has the following characteristics: high consumption of fruits, vegetables, bread and other cereals, potatoes, beans, nuts and seeds; olive oil as an important monounsaturated fat source; low-to-moderate amounts of dairy products, fish and poultry, with red meat eaten rarely; eggs consumed up to four times a week; and low to moderate consumption of wine.