Summary
Resveratrol has been reported to improve metabolic function in metabolically-abnormal rodents and humans, but has not been studied in non-obese people with normal glucose tolerance. We conducted a randomized, double-blind, placebo-controlled trial to evaluate the metabolic effects of 12 weeks of resveratrol supplementation (75 mg/day) in non-obese, postmenopausal women with normal glucose tolerance. Although resveratrol supplementation increased plasma resveratrol concentration, it did not change body composition, resting metabolic rate, plasma lipids, or inflammatory markers. A two-stage hyperinsulinemic-euglycemic clamp procedure, in conjunction with stable isotopically-labeled tracer infusions, demonstrated that resveratrol did not increase liver, skeletal muscle, or adipose tissue insulin sensitivity. Consistent with the absence of in vivo metabolic effects, resveratrol did not affect its putative molecular targets, including AMPK, Sirt1, Nampt, and Pgc-1α, in either skeletal muscle or adipose tissue. These findings demonstrate that resveratrol supplementation does not have beneficial metabolic effects in non-obese, postmenopausal women with normal glucose tolerance.