Associations between diet quality and adult acne: A cross sectional study in the UK Biobank

Abstract Background Diet has been implicated in acne pathogenesis, but evidence in adults remains limited, particularly regarding overall diet quality and potential sex differences. Objectives To examine associations between diet quality and adult acne in UK Biobank and explore whether these associations differed by sex. Methods In this cross sectional study, UK Biobank participants aged 37–73 years at recruitment were classified as having current acne, a history of acne or no acne using self‐report and linked health records (ICD‐10: L70). Dietary intake was assessed using food frequency questionnaires and repeated 24‐h recalls. Multivariable logistic regression examined associations between dietary quality indices and current acne, with secondary analyses of food groups and dairy products. Exploratory sex‐stratified analyses assessed effect modification. Results Among 228,757 participants, 1603 (0.7%) had current acne and 5709 (2.5%) reported a history of acne. Participants with acne were younger and more frequently female. Higher adherence to a Mediterranean‐style diet was associated with lower odds of current acne (per score: adjusted odds ratio [aOR] 0.93, 95% CI 0.87–0.99; p = 0.021). In exploratory sex‐stratified analyses, this association was observed in women (aOR 0.90, 95% CI 0.83–0.97; p = 0.007), whereas low‐carbohydrate dietary pattern scores were associated with higher odds in men (aOR 1.04, 95% CI 1.01–1.08; p = 0.018). Cooked vegetables and yoghurt were inversely associated with acne, whereas pork, skimmed milk and milk‐based desserts showed positive associations. Conclusions Diet quality was modestly associated with adult acne in this UK middle‐aged and older population, with exploratory evidence of sex differences. Given the cross sectional design, modest effect sizes and possible diagnostic misclassification with rosacea in routine healthcare records, these findings should be interpreted cautiously. Prospective and interventional studies with detailed dermatological phenotyping are needed to establish causality and clinical relevance.