Abstract
BACKGROUND: The Mediterranean (MED) dietary pattern improves cardiovascular disease (CVD) risk factors. Increased central systolic blood pressure and arterial stiffness are independent predictors of CVD. The effect of a MED diet on these measures of vascular health has not been investigated. OBJECTIVES: The aim was to evaluate the effects of a MED diet incorporating 0.5 oz./d (MED0.5), 2.5 oz./d (MED2.5) and 5.5 oz./d (MED5.5) of lean beef compared with an Average American diet (AAD) on vascular health [brachial and central blood pressure, pulse wave velocity (PWV), and augmentation index]. METHODS: A multicenter, 4-period randomized, crossover, controlled-feeding study was conducted at Penn State University and USDA, Beltsville. In random sequence order, participants consumed each test diet for 4 wk. Vascular outcomes were assessed at baseline and the end of each diet period. Linear mixed models were used for analyses. RESULTS: Between-diet differences were observed for peripheral and central blood pressure as well as PWV (P < 0.05). PWV was lower following MED0.5 [-0.24 m/s; 95% confidence interval (CI): -0.44, -0.04] and MED2.5 (-0.27 m/s; 95% CI: -0.47, -0.07) compared with the AAD; PWV was nominally lower after the MED5.5 compared with the AAD (-0.20 m/s; 95% CI: -0.40, 0.003; P = 0.055). Central systolic blood pressure was lower following the MED0.5 (-3.24 mmHg; 95% CI: -5.22, -1.27) and MED2.5 (-2.93 mmHg; 95% CI: -4.91, -0.96) compared with the AAD. A similar pattern was observed for central diastolic pressure. Brachial systolic and diastolic pressure were lower following all 3 MED diets compared with the AAD (P < 0.05). CONCLUSIONS: Compared with an AAD, MED diets containing 0.5 and 2.5 oz./d of lean beef improved brachial and central systolic and diastolic blood pressure and arterial stiffness. Our findings suggest that a MED diet with ≤5.5 oz./d of lean beef does not adversely affect vascular function.This trial was registered at clinicaltrials.gov as NCT02723617.