Effects of 12 Months Consumption of 100 g Dried Plum (Prunes) on Bone Biomarkers, Density, and Strength in Men

Several male animal studies have demonstrated bone-protective effects of dried plum; however, no human male study has evaluated the effect of dried plum on bone health. We conducted a randomized controlled clinical study to test if daily inclusion of 100 g of dried plum in the diet positively influenced bone mineral density (BMD), bone strength, and bone biomarkers in men. Sixty-six men were randomly assigned to one of two daily treatment groups: (1) control (0 g dried plum) or (2) 100 g dried plum. Blood samples were collected at baseline and after 3, 6, and 12 months to assess bone biomarkers. Bone was measured at baseline and after 6 and 12 months via dual-energy X-ray absorptiometry and peripheral quantitative computed tomography. Tartrate-resistant acid phosphatase-5b (TRAP5b) and C-terminal collagen cross-link (CTX) levels decreased significantly in the dried plum group at 3-, 6-, and 12-month intervals compared with baseline. No changes were observed in the control group for TRAP5b and CTX levels. Bone-specific alkaline phosphatase levels decreased significantly after 6 and 12 months in the control and dried plum groups. BMD for total body, spine (L1-L4), hip, and ulna did not change in the control and dried plum groups from baseline to 6 or 12 months. In the proximal tibia, endosteal circumferences increased significantly within the dried plum group during the course of treatment. The results suggest that daily consumption of 100 g dried plum for 12 months has modest bone-protective effects in men. ClinicalTrials.gov identifier: NCT04720833.