This study aims to determine the effects of consuming sweet cherry juice on cardiovascular function, glucose regulation, and lipid status in overweight human subjects. The investigators hypothesize that sweet cherry juice consumption will improve metabolic and physiological status in overweight persons compared to a placebo.
The investigators will conduct a randomized, cross-over study lasting 14 weeks and including 1 week for screening/enrollment, 1 week baseline assessment, and two intervention periods of 6 weeks each for the cherry juice and placebo interventions. Two test visits, 3 to 7 days apart, will occur before the start of intervention (baseline, or week 0) and then at weeks 6 and 12. Participants will be randomized to consume either the cherry juice or placebo beverage first, and will cross over to the alternate intervention immediately following the end of the first 6 weeks. Test Visit 1 will include measures of blood pressure, vascular tone, liver fat and stiffness, post-prandial metabolic response to the study beverage, cardiovascular activity and function, and nervous system control of cardiovascular activity and tone. Acute effects of study beverages will be measured, as will the chronic effects of study beverage consumption after 6 weeks. At Test Visit 2, participants will take a standard 75 gram oral glucose tolerance test (OGTT). Participants will be equipped with physiological monitoring devices, which will monitor cardiovascular activity and function and nervous system control of cardiovascular activity and tone, and continuously measure blood pressure. A series of cognitive function tasks will be administered, and a mental stress test will be conducted. The Test Visit 1 and 2 will be repeated at week 6 and week 12 following each intervention with cherry juice or the placebo beverage.