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 ( 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; = 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 ( 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.