Effects of Prunes on Bone Density in Humans: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Background: Recent studies suggest that prunes are one of the most effective fruits for preventing and reversing bone loss. Objectives: The purpose of the present systematic review was to summarize the evidence from the randomized controlled studies on the effect of prunes on bone health in humans and to pool the results in a meta-analysis. The hypothesis of the present review was that bone mineral density of the pulled intervention group would be higher than that of the control group. Methods: We conducted a systematic review of randomized controlled studies with a three-level mixed-effects meta-analysis. Results: Of two hundred and eighty-four studies that were initially identified in PubMed, Scopus, and Web of Science using the search words, eleven papers (747 participants) were considered eligible. The effect of prune intervention in postmenopausal women was borderline significant at the lumbar spine, with BMD slightly higher in the intervention group (SMD [95% CI] = 1.30 [-0.03, 2.63]; I² = 98%; p < 0.001). No significant differences were observed at other individual BMD sites. Heterogeneity across studies was high for all measured sites. The difference between the intervention and control groups in the levels of bone formation and resorption markers was not significant. The risk of bias of the included randomized controlled studies, assessed by the RoB v.2 tool, was low. Conclusions: Our meta-analysis provides preliminary evidence of modest skeletal benefits associated with consumption of 50-100 g of prunes, particularly at the lumbar spine, a trabecular-rich site. However, the overall body of research remains limited.