The effects of β-carotene on osteoporosis: a systematic review and meta-analysis of observational studies

Abstract

Purpose: The aim is to evaluate the effect of β-carotene for osteoporosis and provide quantitative evidence.

Method: PubMed, Embase, Web of Science, and Cochrane Library were searched for eligible studies. Fifteen studies were included. Random-effect model was applied to pool the odds ratio (OR). The risk of osteoporosis and fracture were compared between low β-carotene intake group and high β-carotene intake group.

Result: The intake of β-carotene was unassociated with the overall risk of osteoporosis [OR = 0.733, 95% Cl (0.528, 1.018), p = 0.064]. Subgroup analysis showed that the intake of β-carotene was negatively associated with the risk of osteoporosis in both male subgroup [OR = 0.7, 95% Cl (0.549, 0.893), I² = 40.40%, p = 0.004] and female subgroup [OR = 0.684, 95% Cl (0.487, 0.960), I² = 86.40%, p = 0.028]. There was also a negative association between β-carotene intake and osteoporosis in Asia subgroup [OR = 0.512, 95% Cl (0.403, 0.650), I² = 0.00%, p = 0], whereas no association was observed in Western subgroup [OR = 1.107, 95% Cl (0.908, 1.350), I² = 2.30%, p = 0.314]. In addition, random-effect model was adopted to pool the standard mean difference (SMD), and the results showed that β-carotene intake was positively associated with overall bone mineral density (BMD) [SMD = - 0.213, 95% Cl (- 0.391, - 0.034), I² = 87.30%, p = 0.019]. Subgroup analysis showed that β-carotene intake was positively associated with BMD in Asian participants [SMD = - 0.394, 95% Cl (- 0.461, - 0.328), I² = 0, p = 0], while unassociated in Western participants [SMD = - 0.047, 95% Cl (- 0.314, 0.219), I² = 78.9%, p = 0.727].

Conclusion: β-carotene may improve BMD and reduce the risk of osteoporosis and fracture. However, these effects could vary by gender and race and need to be further validated by longitudinal studies.

Keywords: Fracture; Meta-analysis; Osteoporosis; β-carotene.