The PREvención con DIeta MEDiterránea (PREDIMED) trial showed that Mediterranean diets (MedDiets) supplemented with either extra virgin olive oil or nuts reduced cardiovascular events, particularly stroke, compared with a control, lower fat diet. The mechanisms of cardiovascular protection remain unclear.
We evaluated the 1-year effects of supplemented MedDiets on 24-hour ambulatory blood pressure (BP), blood glucose, and lipids.
Randomized, parallel-design, controlled trial was conducted in 2 PREDIMED sites. Diets were ad libitum, and no advice on increasing physical activity or reducing sodium intake was given.
Participants were 235 subjects (56.5% women; mean age, 66.5 years) at high cardiovascular risk (85.4% with hypertension). Adjusted changes from baseline in mean systolic BP were −2.3 (95% confidence interval [CI], −4.0 to −0.5) mm Hg and −2.6 (95% CI, −4.3 to −0.9) mm Hg in the MedDiets with olive oil and the MedDiets with nuts, respectively, and 1.7 (95% CI, −0.1 to 3.5) mm Hg in the control group (P<0.001).
Respective changes in mean diastolic BP were −1.2 (95% CI, −2.2 to −0.2), −1.2 (95% CI, −2.2 to −0.2), and 0.7 (95% CI, −0.4 to 1.7) mm Hg (P=0.017). Daytime and nighttime BP followed similar patterns. Mean changes from baseline in fasting blood glucose were −6.1, −4.6, and 3.5 mg/dL (P=0.016) in the MedDiets with olive oil, MedDiets with nuts, and control diet, respectively; those of total cholesterol were −11.3, −13.6, and −4.4 mg/dL (P=0.043), respectively.
In high-risk individuals, most with treated hypertension, MedDiets supplemented with extra virgin olive oil or nuts reduced 24-hour ambulatory BP, total cholesterol, and fasting glucose.