The role of antioxidant rich berries in the prevention of postmenopausal bone loss

Postmenopausal osteoporosis is the most prevalent form of osteoporosis and results in fragility fractures. Smoking is one of the major risk factors for osteoporosis and is known to aggravate bone loss in postmenopausal women due to increased oxidative stress and inflammation. Diet-based interventions using berries have shown bone protective affects in animal studies partially due to antioxidant and anti-inflammatory properties of their phenolic compounds. The goal of this research was to determine the effects of antioxidant-rich fruits in the prevention of postmenopausal bone loss. Our first study examined the dose dependent effects of blackberries in preventing bone loss in an ovariectomized rat model of postmenopausal osteoporosis. Findings from the animal study indicated that blackberries consumed at the level of 5% (w/w) and not 10% (w/w) may modestly prevent ovariectomy-induced bone loss. Next, we conducted a clinical study to determine the effects of berries on bone loss. To explore this objective, postmenopausal smokers were required to consume 45g of blackberries or blueberries for a 9 month period. Bone mineral density of total body, and sites were determined at baseline and after 9 months. In addition, biomarkers of bone metabolism and biomarkers of oxidative stress were measured. This study found that blackberries and not blueberries modestly protected against smoking-induced bone loss of the total body bone mineral density. No significant changes were noted on biomarkers and other bone indices. The results of this research are inconclusive. Future studies are necessary to confirm these findings and explore mechanisms by which berries may prevent bone loss and effective doses in both postmenopausal smokers and nonsmokers.