The effect of whole-grape powder on body composition, serum biomarkers of adipose tissue and bone metabolism in postmenopausal women

The effects of consuming freeze-dried, whole-grape powder (GP) or a placebo powder (P) for 12 weeks on body composition, biomarkers of inflammation, adipose tissue, and bone metabolism were determined. A randomized, double-blind, placebo-controlled study was performed with 40 post-menopausal women (mean age 52.4±7.4) from 16 cities in Texas. Body composition and bone mineral densities (BMD) were determined using dual-energy X-ray absorptiometry (DXA). Serum concentrations of cross-linked N-telopeptide of type I collagen (NTX), alkaline phosphatase (ALP), osteocalcin (OC), insulin-like growth factor-1 (IGF-1), adiponectin, leptin, prostaglandin E2 (PGE2), and leukotriene E4 (LTE4) were assayed using enzyme-linked immunosorbent assays (ELISA). Participants' BMD were within normal ranges at baseline and at the end of study. NTX (p=0.04) and ALP (p=0.04) were significantly different between groups at baseline. In the P group (n=14), OC (p<0.01), adiponectin (p=0.01), and LTE4 (p=0.02) significantly decreased by 60.6%, 45.8%, and 61.9%, respectively. OC (p=0.02) and adiponectin (p=0.02) significantly decreased in GP group (n=11) by 50.9% and 59.7%, respectively. There were no significant differences between groups at 12 weeks. In the short-term, freeze-dried whole-grape powder may exert no favorable effects on bone or adipose tissue biomarkers in post-menopausal women. This research was funded and supported by California Table Grape Commission.