Short-term resveratrol supplementation stimulates serum levels of bone-specific alkaline phosphatase in obese non-diabetic men

Despite the substantial preclinical evidence for a positive effect of the polyphenolic compound resveratrol, human data are very scarce, and currently no clinical data addressing the potential impact on bone metabolism have been published. In the present study we addressed this issue in order to identify potential bone metabolic effects of resveratrol in human subjects. In a randomised, placebo-controlled, double-blinded and parallel-group design, 24 obese [BMI (kg/m2): 34.2 ± 0.7] non-diabetic men were randomly assigned to 500 mg resveratrol or placebo treatment three times daily for four weeks. Biomarkers of bone metabolism, inflammatory parameters and circulating hormones were measured before and after the intervention period. Plasma levels of bone-specific alkaline phosphatase increased significantly in the resveratrol group as compared to placebo [delta changes (U/l); resveratrol: 4.9 ± 0.6 vs. placebo: −1.7 ± 0.7; P < 0.001]. This was paralleled by a tendency of total alkaline phosphatase to rise within the resveratrol group (P = 0.061), whereas no changes were detected in other biomarkers of bone and calcium metabolism, including PINP, osteocalcin, CTx, or PTH. We suggest that resveratrol influences bone metabolism possibly representing a primary anabolic modality in preserving bone integrity. However, the clinical implications remain to be evaluated.