The original concept of the Mediterranean diet originated from a study conducted in the 1950’s and 60’s. The study showed that despite a high fat intake (primarily monounsaturated fat from olive oil), the population of the island of Crete had very low rates of coronary heart disease . The researchers speculated that the traditional diet followed on Crete and in much of Greece was responsible for the overall good health of the population. This diet is characterized by a high intake of vegetables, legumes, fruits, nuts, unrefined cereals, olive oil, and fish. It also includes some dairy products (primarily cheese and yogurt), low intake of saturated fats, and little meat and poultry. Alcohol tends to be consumed regularly, however, consumption is moderate and usually occurs as wine with a meal.

Now, a new study, published in the June 26, 2003 issue of the New England Journal of Medicine , finds that following the traditional Mediterranean diet is associated with a reduction in death from all causes, including coronary heart disease and cancer.

About the study

This was a population-based, prospective study involving 22,043 adults in Greece. Upon entering the study, each participant completed an extensive questionnaire designed to determine the frequency with which they consumed approximately 150 types of foods and beverages typical to Greece over the year preceding the study. Another section of the questionnaire examined each participant’s level of physical activity.

The degree to which the participants in the study adhered to the traditional Mediterranean diet was assessed by assigning a value of either 0 or 1 to each of nine food categories: vegetables, legumes, fruits and nuts, cereal, fish, meat, poultry, dairy products, and fat intake (monounsaturated fats versus saturated fats).

The findings

The study participants were followed for just under four years (44 months), during which time there were 275 deaths. The researchers found that participants who had a high degree of adherence to the typical Mediterranean diet had a significantly reduced rate of death from all causes. This same inverse relationship was seen in death due to both coronary heart disease and cancer, although the relationship was slightly stronger for coronary heart disease. It was also independent of other factors such as sex, smoking status, level of education, body-mass index (a measure of overweight), waist-to-hip ratio, and level of physical activity.

How does this affect you?

The researchers concluded that the more strictly the participants of the study adhered to the traditional Mediterranean diet, the greater their reduction in risk for death from all causes, including coronary heart disease and cancer. In general, no one component of the Mediterranean diet was found to be responsible for these findings. Instead, researchers theorize that the health benefits seen from adhering to the Mediterranean diet arise from the combined effect of all the components of the diet and that the exact biologic interactions that cause these results may be difficult to determine unless a very large sample population is studied.

The researchers made every effort to eliminate the possibility that factors other than diet contributed to lower mortality rates in their study. It is plausible, however, that strict adherence to a favorable health-related regimen—any regimen—is what accounted for the increased longevity. If this were the case, the components of the Mediterranean diet would not be relevant, but the act of sticking to it would be.

A perspective piece published in the same issue of the journal cautions that in the past, the Mediterranean diet has been surrounded by as much myth as scientific evidence, and that researchers and the public alike should bear in mind that there is no single “Mediterranean diet.” Indeed, the Mediterranean Sea is surrounded by as many as 15 different countries each with its own culture and dietary habits.