The Mediterranean Diet

The Mediterranean diet is derived from the traditional diets of Greece, southern Italy and Spain.  Its uniqueness relates to the use of olive oil instead of butter and the daily consumption of nuts, legumes, fruits and vegetables.  People in the Mediterranean countries depending on their local (island, valleys or mountains) eat moderate amount of fish, or meat such as poultry and/or dairy products (mostly as cheese and yogurt).  They also drink a low amount of wine and/or spirits.  According to the American Heart Association, there's no one "Mediterranean" diet but a dietary pattern that includes the above-mentioned foodstuff and the use of olive oil a monounsaturated fat that does not raise blood cholesterol.

The incidence of heart disease and death rates in Mediterranean countries is lower than in the United States.  Although diet appears to have a role, other factors such as genetic, lifestyle, physical activity and extended social and family support systems may also play a part.

Before advising people to adhere to a strict Mediterranean diet, well designed and controlled studies are needed to determine whether the diet itself or other factors (genes, lifestyle, social) account for the lower deaths from cardiovascular disease among humans.  The findings from the following two studies are supportive of the beneficial effect the Mediterranean diet and the consumption of nuts has in our health. 

An important multi-center study that was conducted in Spain was published in the New EnglandJournal of Medicine.  The authors evaluated the effect of the Mediterranean diet in the prevention of cardiovascular disease in individuals who were at high risk for cardiovascular events, but with no apparent cardiovascular disease. A total of 7447 persons were enrolled whose age ranged from 55 to 80 years; with a male to female ratio 43 to 57 percent were randomly assigned, to one of three diets: a Mediterranean diet supplemented with extra-virgin olive oil, a Mediterranean diet supplemented with mixed nuts, or a control diet (advice to reduce dietary fat). The end point was the rate of major cardiovascular events such as myocardial infarction, stroke, or death from cardiovascular causes. A primary end-point event occurred in 288 participants.  The group assigned to a Mediterranean diet with extra-virgin olive oil experienced 96 events while and the group assigned to a Mediterranean diet with nuts experienced 83 events, respectively, versus 109 events in the control group. On the basis of these results, the trial was stopped after a median follow-up of 4.8 years as the authors concluded that among persons at high cardiovascular risk, a Mediterranean diet supplemented with extra-virgin olive oil or nuts reduced the incidence of major cardiovascular events.

According to a study from the USA that was also published in the New England Journal of Medicine, people who ate a daily handful of nuts were less likely to die from any cause over a 30-year period and were more slender than those who didn’t consume nuts.  For their research, the authors analyzed information from the Nurses’ Health Study that provided data on 76,464 women, and the Health Professionals’ Follow-Up Study that provided data on 42,498 men. The researchers report a 29% reduction in deaths from heart disease and an 11% reduction in death rate from cancer.  It appeared that the protective effect was similar to all types of nuts.  Those who ate nuts less than once a week had a 7 percent reduction in mortality; once a week, 11 percent reduction; two to four times per week, 13 percent reduction; five to six times per week, 15 percent reduction; and seven or more times a week, a 20 percent reduction in death rate. 

Based on this and other smaller studies, the U.S. Food and Drug Administration concluded that eating 1½ ounce per day of most nuts “may reduce the risk of heart disease.”