Vegetarian and Vegan Diets and the Risk of Hip Fracture in Adults: A Systematic Review and Meta-analysis

INTRODUCTION: Hip fracture is an important cause of hospitalization, with high morbidity and mortality. Evidence suggests that vegetarians and vegans have lower bone mineral density, and plant-based diets are gaining popularity. However, the impact of these diets on the occurrence of hip fracture risk remains unclear. OBJECTIVE: This systematic review aimed to assess the impact of vegetarian and vegan diets on the risk of hip fracture in adults. METHODS: We conducted a systematic review of studies comparing vegetarians and vegans with meat-eaters. We searched Medline, EMBASE, LILACS, CINAHL, Scopus, and Cochrane Central Register of Controlled Trials (CENTRAL). Two reviewers independently and in duplicate performed study selection, risk-of-bias assessment, and data extraction. Hazard ratios (HRs) with 95% CIs were calculated as an estimate of the effect of vegetarian and vegan diets. The quality of evidence was determined according to the Grading of Recommendations Assessment, Development, and Evaluation. RESULTS: Four cohort studies with 529 672 participants were included. Both vegetarian and vegan diets were associated with a higher risk of hip fracture after adjusting for confounders. Vegetarians had a 25% higher risk than meat-eaters (HR, 1.25; 95% CI, 1.11-1.39; 38 433 vegetarians; I2 = 0%; low certainty of evidence). Vegans had a 75% higher risk (HR, 1.75; 95% CI, 1.17-2.63; 5344 vegans; I2 =64%; very low certainty of evidence). CONCLUSION: These findings emphasize the importance of incorporating dietary patterns into strategies for promoting bone health, especially among individuals following plant-based diets. Healthcare providers should offer guidance to individuals adopting vegetarian or vegan diets to ensure adequate nutrient intake and support bone health. SYSTEMATIC REVIEW REGISTRATION: PROSPERO no. CRD 42024592448.