Abstract
Background: Oxidative stress and inflammation contribute to osteoporosis. Berries provide polyphenols especially anthocyanins that may modulate bone remodeling. This review is the first to synthesize evidence specifically on berries and bone health, integrating human, animal, and in vitro data under the GRADE framework. Methods: We systematically searched PubMed, Embase, Web of Science, Scopus, and the Cochrane Library through 23 April 2025 for human, animal, and in vitro studies on berries or berry-derived compounds and bone outcomes. Risk of bias was assessed with RoB 2.0, ROBINS-I, SYRCLE, and an adapted ToxRTool; certainty of human evidence was appraised with GRADE. Results: Nineteen studies were included (5 human, 9 in vivo, 5 in vitro). Observational cohorts linked higher anthocyanin intake with greater BMD. Small randomized trials suggested modest benefits of blackcurrant and blueberry on whole-body BMD, bone turnover markers, and calcium retention, while results for biomarkers were mixed. Animal models generally showed attenuation of ovariectomy- or age-related bone loss, and in vitro experiments indicated inhibition of osteoclastogenesis with stimulation of osteoblast activity. By GRADE, certainty was low-moderate for BMD, low for biomarkers, and very low for fractures. Conclusions: Berry polyphenols may support skeletal health via antioxidant and anti-resorptive mechanisms, but current clinical evidence is limited by small samples, heterogeneity, and lack of fracture outcomes. Larger, longer, standardized RCTs with exposure profiling are needed before dietary recommendations can be made.