Consumption of milk and dairy products and risk of osteoporosis and hip fracture: a systematic review and Meta-analysis

Abstract

Background: Although some studies have reported the beneficial effects of milk and dairy product consumption on osteoporosis and risk of fracture, the findings are conflicting.

Purpose: We summarized earlier data on the association between milk and dairy intake and risk of osteoporosis and hip fracture through a meta-analysis.

Methods: A systematic literature search of relevant reports published in PubMed, ISI (Web of Science), EMBASE, SCOPUS, and Google Scholar until August 2018 was conducted.

Results: Total dairy intake was protectively associated with reduced risk of osteoporosis based on cross-sectional and case-control studies (0.63; 95% CI: 0.55–0.73). Milk consumption was not associated with the risk of osteoporosis (overall RR = 0.79; 95% CI: 0.57–1.08). In non-linear dose–response meta-analysis, increase intake of dairy (at the level of 0 to 250 grams per day) was associated with a reduced risk of osteoporosis (P_nonlinearty = 0.005). Meta-regression of included studies revealed an inverse linear association between dairy and milk intake and risk of osteoporosis; such that every additional 200-gram intake of dairy and milk was associated with a 22% and 37% reduced risk of osteoporosis, respectively. In terms of hip fracture, milk consumption was associated with a 25% reduced risk of hip fracture only in cross-sectional and case-control studies (overall RR = 0.75; 95%CI: 0.57–0.99). In linear meta-regression, every additional 200-gram milk intake per day was associated with a 9% greater risk of hip fracture in cohort studies.

Conclusion: Despite an inverse association between milk and dairy intake and risk of osteoporosis and hip fracture in cross-sectional and case-control studies, no such association was seen in cohort studies. Given the advantages of the cohort over case-control studies, we concluded that a greater intake of milk and dairy products was not associated with a lower risk of osteoporosis and hip fracture

Keywords:

• Milk
• dairy
• osteoporosis
• hip fracture
• meta-analysis

Disclosure statement

Authors declared no personal or financial conflicts of interest.

Funding

This study was financially supported by a joint collaboration of Endocrinology and Metabolism Molecular-Cellular Sciences Institute, Tehran University of Medical Sciences, and School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Iran. Dr. Ahmad Esmaillzadeh was supported by a grant from Iran National Science Foundation (INSF).