Effect of Mediterranean Diets with Varying Amounts of Lean Beef on Measures of Vascular Health

Abstract

Abstract Objectives To evaluate the effects of Mediterranean (MED) diets with different quantities of lean beef (0.5, 2.5 and 5.5 oz/day) compared to an Average American diet (AAD) on brachial and central blood pressure, pulse wave velocity (PWV) and augmentation index (AI). Methods We conducted a multicenter, 4-period controlled feeding, randomized crossover study at Penn State University and USDA-Beltsville to evaluate the effects of MED diets (CHO 42%, PRO 17%, FAT 41%, SFA 8%, MUFA 26%, PUFA 8%) with different quantities of lean beef (0.5, 2.5 and 5.5 oz/day) compared to an average American diet (AAD; CHO 52%, PRO 15%, FAT 33%, SFA 12%, MUFA 13%, PUFA 8%) on vascular health. Participants (n = 66) included generally healthy males and females (BMI = 20–38 kg/m2) 30 to 67 years. Participants were randomized to each of the 4 diets for 4 weeks with an approximate 2-week break between treatments. Central blood pressure, PWV and AI were measured using the SphygmoCor ECEL-System. Endpoints were assessed at baseline and the end of each 4-week diet period. Results There was a significant treatment effect for PWV (P < 0.01); PWV was lower following consumption of the MED diets containing 0.5 oz. lean beef/day (6.86 m/sec ± 0.14; P < 0.05) and 2.5 oz. of lean beef/day (6.84 m/sec ± 0.15; P < 0.01) compared to the AAD (7.10 m/sec ± 0.14). Compared to the AAD, both the 0.5 oz./day (−3.30 mmHg ± 0.76) and 2.5 oz./day (−2.94 mmHg ± 0.76) MED diets elicited greater reductions in central systolic blood. A similar pattern was observed for central diastolic pressure. Compared to AAD, all three MED diets significantly decreased brachial systolic and diastolic pressures (P < 0.01 for all). Compared to baseline only the MED 0.5 elicited a significant reduction in AI (P < 0.01). Conclusions This study demonstrated improvements in measures of arterial stiffness and central blood pressure following Mediterranean diets containing low to moderate amounts of lean beef. Funding Sources National Cattleman's Beef Association, The Penn State Clinical and Translational Research Institute, Pennsylvania State University Clinical and Translational Science Award, and NIH/National Center for Advancing Translational Sciences grant no. UL1TR000127.