LAUSR

Objectives To examine whether daily incorporation of 40 grams of whole blueberry into the diets of postmenopausal women with mild to moderate degree of bone loss will positively influence indices of bone metabolism. Methods In a randomized, double-blind control trial, 40 postmenopausal women with mild to moderate degree of bone loss, not on hormone or other bone therapies, were randomized to either consume 40 g of lyophilized blueberry powder (LBP) (n = 20) or a placebo powder (n = 20) daily for 90 days. Plasma bone biomarkers including sclerostin, bone-specific alkaline phosphatase (B-ALP), receptor activator of nuclear factor kappa-Β ligand (RANKL), tartrate-resistant acid phosphatase (TRAP5) and inflammatory marker, interleukin(IL)-6 was assessed at baseline, mid-point (45 days) and final (90 days). Bone density and body composition was assessed at baseline and final visits only. Fracture risk assessment tool (FRAX) was utilized to determine major osteoporotic fracture risk. Results A total of 32 participants completed the study with an attrition rate of 20%. A significant increase of B-ALP was observed at mid-point in the blueberry treatment group, indicating increased bone formation, however the increase was not maintained at final point. In addition, a more pronounced decline in RANKL was observed at final point in the LBP group as compared to the placebo group. A slight decline in the probability of a major osteoporotic fracture was observed in the LBP group, while an increase of such risks was observed in the placebo group. Moreover, in the placebo group, a significant increase in IL-6 was observed at final point, but the LBP group maintained their IL-6 throughout the study with a declining trend from baseline to final point. Besides bone metabolism parameters, body weight was decreased significantly in the blueberry group at final point, along with a more pronounced decrease in %body fat as compared to the placebo group. No changes in bone densities were observed, possibly due to the short study duration. Conclusions The findings of the study suggest that blueberry consumption may have nominal protective effects on bone in postmenopausal women who have mild to moderate bone loss. A longer study duration may more favorably influence bone metabolism and bone density in this population. Funding Sources US Highbush Blueberry Council and Research Enhancement Program at Texas Woman's University.