Milk intake and risk of hip fracture in men and women: A meta-analysis of prospective cohort studies

Abstract

CONTEXT: Milk contains calcium, phosphorus, and protein, and is fortified with vitamin D in the US. All of these ingredients may improve bone health. However, the potential benefit of milk on hip fracture prevention is not well established. OBJECTIVE: To assess the association of milk intake with risk of hip fracture based on a meta-analysis of cohort studies in middle aged or older men and women. DATA SOURCES: English and non-English publications searching Medline (Ovid, Pubmed) and EMBASE up to June 2010; experts in the field; reference lists. STUDY SELECTION: Prospective cohort studies. To compare studies on the same scale, we calculated the relative risk (RR) of hip fracture per glass of milk intake daily (approximately 300 mg calcium per glass of milk). Pooled analyses were based on random effects models. DATA EXTRACTION: By two independent observers. RESULTS: In women (6 studies, 195,102 women, 3574 hip fractures), there was no overall association between total milk intake and hip fracture risk (pooled RR per glass of milk per day = 0.99; 95% CI 0.96 - 1.02; Q-test p-value = 0.37). In men, (3 studies, 75149 men, 195 hip fractures), the pooled RR per daily glass of milk was 0.91 (95% CI 0.81 - 1.01). CONCLUSION: In the meta-analysis of cohort studies, there was no overall association between milk intake and hip fracture in women but more data are needed in men.