Mediterranean diet for secondary prevention cuts all-cause mortality

Adherence to the traditional Mediterranean diet by patients with known heart or cerebrovascular disease was independently linked with a marked reduction in their risk of all-cause mortality in the Italian Moli-Sani Study, reported at the annual congress of the European Society of Cardiology.

Subjects in the top tertile in terms of food intake consistent with the Mediterranean diet were 37 percent less likely to die during more than seven years of follow-up than were those in the bottom tertile, according to the head of the department of epidemiology and prevention at the IRCCS Mediterranean Neurologic Institute in Pozzilli, Italy.

The message for physicians is clear: “Doctors can’t look to statins, aspirin and other cardiovascular drugs as the only way to secondary prevention in cardiovascular disease. Suggestions to follow healthy dietary habits are as important as prescribing drugs.”

The Moli-Sani Study is an ongoing population-based epidemiologic study of 25,000 adults in the mountainous, heavily agricultural Molise region of southern Italy. The one who directs the study, presented a sub study involving 1,197 participants with established coronary heart disease or cerebrovascular disease at entry. Their average age at enrollment was 66 years. Subjects with coronary heart disease outnumbered those with cerebrovascular disease by roughly 2:1.

Food intake was recorded using the European Prospective Investigation into Cancer (EPIC) foodfrequency questionnaire. Investigator assessed adherence to the traditional Mediterranean diet using the Mediterranean Diet Score (MDS), a validated 0-9 scoring system developed as part of the famous Seven Countries Study.

During a median 7.3 years of prospective follow -up, 208 deaths occurred in the study population. A 2 - point increase in the MDS was independently associated with a  21 percent reduction in the risk of mortality in a multivariate Cox proportional hazards analysis adjusted for “everything we could think of,” including baseline demographics, socioeconomic status, energy intake, body mass index, leisure time physical activity, waist-to-hip ratio, smoking status diabetes, standard cardiovascular medications.

Subjects in the top tertile for adherence to the Mediterranean diet, with an MDS of 6-9, had an adjusted 37 percent relative risk reduction in all - cause mortality, compared with those having MDS of 0-3.

The number of deaths is too small at this point in the prospective study to permit analysis of specific causes of death in a statistically valid manner. With another 3 years or so of follow-up, that analysis can and will be done.

The traditional Mediterranean diet is an eating pattern characteristic of the Mediterranean basin. It encourages large intake of vegetables, legumes, fruits, nuts, and cereals, along with moderately high consumption of fish, olive oil as the primary fat source, and moderate alcohol intake during meal, but low to moderate intake of dairy products and low consumption of meat and poultry.

As a sobering aside, in the Molise region, far and away the biggest obstacle to adherence to the Mediterranean diet is economic. “There was no difference in adherence to the Mediterranean diet between different socioeconomic classes in the Moli-Sani Study until 2007-2008, when the Italian economic crisis began. Since then, there are significant differences according to socioeconomic condition. Poor people are obliged to follow the Mediterranean diet less.” Telling a patient with cardiovascular disease who is in a low -income family to eat fish at least twice per week is impractical advice.