Effectiveness of anthocyanin-rich foods on bone remodeling biomarkers of middle-aged and older adults at risk of osteoporosis: a systematic review, meta-analysis, and meta-regression

Context: Current osteoporosis pharmacological treatment has undesirable side effects. There is increasing focus on naturally derived food substances that contain phytonutrients with antioxidant effects in promoting health and regulating immune response. Objective: This review aims to systematically evaluate the effectiveness of anthocyanin-rich foods on bone remodeling biomarkers in middle-aged and older adults (≥40 y old) at risk of osteoporosis. Data Sources: Randomized controlled trials were searched on 8 bibliographic databases of PubMed, Embase, Scopus, Web of Science, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Food Science and Technology Abstracts, Cochrane Library, and ProQuest. Data Extraction and Analysis: Thirteen studies were included in the meta-analysis. Receptor activator of nuclear factor kappa-B ligand (RANKL) is exhibited from osteoblastic cells that gathered osteoclasts to bone sites for bone resorption, accelerating bone loss. Anthocyanin-rich food consumption showed statistically nonsignificant effects, with no substantial heterogeneity on bone remodeling biomarkers. However, there was a significant increase in lumbar spine L1–L4 bone mineral density. Mild-to-small effects were seen to largely favor the consumption of anthocyanin-rich foods. Berries (d ¼ –0.44) have a larger effect size of RANKL than plums (d ¼ 0.18), with statistically significant subgroup differences. Random-effects meta-regression found body mass index, total attrition rate, total energy, and dietary carbohydrate and fat intake were significant covariates for the effect size of RANKL. All outcomes had low certainty of evidence. Conclusion: Anthocyanin-rich foods may improve bone health in middle-aged and older adults at risk of osteoporosis. This review contributes to the growing interest in nutrient-rich foods as a low-cost and modifiable alternative to promote human health and reduce disease burden. Future high-quality studies with larger sample sizes and longer treatment durations are required to fully understand the effect of anthocyanin-rich foods on bone health.