regular consumption of a polyphenol-rich apple does not influence endothelial function: a randomised double-blind trial in hypercholesterolemic adults

Background/objectives: Epidemiological studies suggest that apple consumption is associated with a reduction in cardiovascular disease risk. Apple polyphenols may contribute to explain these effects. Endothelial dysfunction has been associated with early stage of atherosclerosis and polyphenols from various dietary sources have been shown to reverse it. The aim of the present study was to investigate the effect of the consumption of a polyphenol-rich apple on endothelial function. Subjects/methods: In all, 30 hypercholesterolemic volunteers were included in a double-blind, randomized crossover trial. They successively consumed 40 g of two lyophilized apples, polyphenol-rich and polyphenol-poor, providing respectively 1.43 and 0.21 g polyphenols per day during two 4-week periods separated by a 4-week washout period. Results: Brachial artery flow-mediated vasodilation (FMD) was assessed at the beginning and at the end of each intervention period. FMD did not differ between the polyphenol-rich and the polyphenol-poor apples, neither did the other cardiovascular disease risk factors (plasma lipids, homocysteine, antioxidant capacity). Conclusions: These data suggest that over a 4-week period, the consumption of a polyphenol-rich apple does not improve vascular function in hypercholesterolemic patients.