ROME – 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, Giovanni de Gaetano, MD, 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% less likely to die during more than 7 years of follow-up than were those in the bottom tertile, according to Dr. de Gaetano, head of the department of epidemiology and prevention at the IRCCS Mediterranean Neurologic Institute in Pozzilli, Italy.
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. Dr. de Gaetano, who directs the study, presented a substudy 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) food-frequency questionnaire. Dr. de Gaetano and his coinvestigators 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 pioneered by the late Ancel Keys.
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% reduction in the risk of mortality in a multivariate Cox proportional hazards analysis adjusted for “everything we could think of,” according to Dr. de Gaetano, including baseline demographics, socioeconomic status, energy intake, body mass index, leisure time physical activity, waist-to-hip ratio, smoking status, diabetes, standard cardiovascular risk factors, and use of cardiovascular medications.
Subjects in the top tertile for adherence to the Mediterranean diet, with an MDS of 6-9, had an adjusted 37% relative risk reduction in all-cause mortality, compared with those having an 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, Dr. de Gaetano said.
The traditional Mediterranean diet is an eating pattern characteristic of the Mediterranean basin, he explained. 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 meals, but low-to-moderate intake of dairy products and low consumption of meat and poultry.
As a sobering aside, he said that 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,” Dr. de Gaetano said.
Telling a patient with cardiovascular disease who is in a low-income family of four to eat fish at least twice per week is impractical advice, he explained.
The ongoing Moli-Sani Study is funded by the Italian government. Dr. de Gaetano reported having no financial conflicts of interest.