The effect of milk consumption on acne: a meta-analysis of observational studies

Acne is a common skin condition in developed countries with western diets. The effect of milk on acne has been highly controversial. To examine the association between milk consumption and acne risk, we conducted a meta-analysis of available data.

We carried out comprehensive databases search of PubMed, Embase, Medline and Cochrane Library and identified four cohort studies and nine case-control or cross-sectional studies, including a total of 71 819 participants. We evaluated the pooled odds ratio (OR) with its 95% confidence interval (CI) using a random effects model. Subgroup analyses on acne severity, milk forms and milk intake levels were performed.

Compared with non-consumers, the pooled OR was 1.16 (95% CI 1.09-1.24) for overall milk consumers in all included studies, and 1.17 (95% CI 1.10-1.24) in cohort studies and 1.16 (95% CI 1.09-1.24) in case-control or cross-sectional studies. Subgroup analysis on milk forms determined a stronger association in skim milk consumers (OR = 1.24, 95% CI 1.13-1.37) than in low-fat consumers (OR = 1.14, 95% CI 1.08-1.22) and full-fat consumers (OR = 1.13, 95% CI 1.05-1.21). The pooled OR was greater for high intake level of milk (OR = 1.12, 95% CI 1.01-1.24) than medium intake level of milk (OR = 1.08, 95% CI 1.00-1.17). A subset study of moderate-to-severe acne also found a positive association with milk consumption (OR 1.18, 95% CI 1.01-1.37), while no statistically significant association was found between mild acne risk and milk consumption (OR 1.14, 95% CI 0.86-1.51).

This meta-analysis provides evidence of a positive association between milk consumption and acne risk.