A Mediterranean-Style Diet with Lean Beef Lowers Blood Pressure and Improves Vascular Function: Secondary Outcomes from a Randomized Crossover Trial

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.