Mediterranean diet may lower death risk in women

Higher adherence to the Mediterranean diet confers a 23-percent reduction in the risk of all-cause mortality, a benefit that may be partially explained by potential mediation by several cardiometabolic factors, according to a study.

The study included 25,315 initially healthy women (mean baseline age 54.6 years, 94.9 percent White) from the Women’s Health Study. All of them provided blood samples, completed a validated food-frequency questionnaire, and underwent biomarker measurements.

Researchers computed the Mediterranean diet score (range, 0–9) based on nine dietary components. Blood biomarkers such as traditional and novel lipid, lipoprotein, apolipoprotein, inflammation, insulin resistance, and metabolism measurements were evaluated at baseline using standard assays and nuclear magnetic resonance spectroscopy. Medical and death records were used to ascertain mortality and cause of death.

A total of 3,879 deaths were recorded over a mean follow-up of 24.7 years. The median Mediterranean diet adherence score in the cohort was 4.0. Compared with low adherence (score 0‒3), higher adherence scores were associated with a lower risk of all-cause death (middle score [4‒5]: hazard ratio [HR], 0.84, 95 percent confidence interval [CI], 0.78–0.90; upper score [6‒9]: HR, 0.77, 95 percent CI, 0.70–0.84; p<0.001 for trend).

In an analysis controlling for lifestyle factors, the beneficial effect of higher adherence to the Mediterranean diet on all-cause death risk was attenuated but remained significant (middle adherence score: HR, 0.92, 95 percent CI, 0.85–0.99; upper adherence score: HR, 0.89, 95 percent CI, 0.82–0.98; p=0.001 for trend).

Small molecule metabolites and inflammatory biomarkers had the strongest association with the decreased risk of death, explaining 14.8 percent and 13.0 percent, respectively, of the association. These were followed by triglyceride-rich lipoproteins (10.2 percent), BMI (10.2 percent), and insulin resistance (7.4 percent).