Flavanones protect from arterial stiffness in postmenopausal women consuming grapefruit juice for 6 mo: a randomized, controlled, crossover trial.

Background: The consumption of citrus fruits is associated with health benefits. However, clinical data regarding the effects of grapefruit flavanone consumption on vascular function are lacking. Objective: The objective of the present study was to address the role of flavanones in the long-term effects induced by grapefruit juice (GFJ) consumption on vascular function in healthy postmenopausal women. Design: Forty-eight healthy postmenopausal women aged 50-65 y within 3-10 y since menopause, a body mass index (in kg/m²) of 19-30, and a waist size >88 cm completed this double-blind, randomized, controlled, crossover trial. These volunteers were randomly assigned to consume 340 mL GFJ/d, providing 210 mg naringenin glycosides, or a matched control drink without flavanones for 6 mo each, with a 2-mo washout between beverages. The primary endpoint was the assessment of endothelial function in the brachial artery by using flow-mediated dilation. Blood pressure, arterial stiff-} ness, and endothelial function in the peripheral arterial bed were also evaluated as indicators of vascular function. These measurements and blood collection for clinical biochemical markers were performed in overnight-fasted subjects before and after the 6-mo treatment periods. Results: The mean ± SD carotid-femoral pulse wave velocity, which reflects central aortic stiffness, was statistically significantly lower after consumption of GFJ (7.36 ± 1.15 m/s) than after consumption of the matched control drink without flavanones (7.70 ± 1.36 m/s), with a P value of 0.019 for the treatment effect. Endothelial function in macro- and microcirculation, blood pressure, anthropometric measures, glucose metabolism, and biomarkers of inflammation and oxidative stress were not affected by the intervention. Conclusions: Regular GFJ consumption by middle-aged, healthy postmenopausal women is beneficial for arterial stiffness. This effect may be related to flavanones present in grapefruit. This trial was registered at clinicaltrials.gov as NCT01272167. [ABSTRACT FROM AUTHOR]