A pilot study of 15 subjects will be completed to determine whether acute consumption of cranberry juice has an effect on endothelial function. We will then complete a randomized, double blind, placebo controlled crossover study designed to investigate the effects of cranberry juice consumption on endothelial function. Participants (n=40) will drink 480 ml of double strength cranberry juice or a similar appearing and tasting placebo per day for four weeks. After a two week rest period, they will cross over to the other beverage. We will examine endothelial function before and after each of the two treatment periods. The study will provide information about the chronic vascular effects of cranberry juice.