Poor Diet and Oral Cavity Cancer Risk in Smoking and Non‐Smoking Men and Women: An Analysis of Three US Cohorts

INTRODUCTION: Oral cavity cancer (OCC) incidence is rising among non-smokers and younger individuals without traditional risk factors. While carcinogenic exposures such as tobacco and alcohol are well studied, the association between unhealthy dietary patterns and OCC has been minimally explored. This study evaluated the association between dietary patterns and OCC risk in men and women. METHODS: This prospective cohort study used data from three large U.S. longitudinal cohorts: the Nurses' Health Study (n = 68 715, 1986-2016), Nurses' Health Study II (n = 93 887, 1991-2017), and the Health Professionals Follow-up Study (n = 47 923, 1986-2016). Participants included 162 602 women and 47 923 men without cancer at baseline. Dietary intake was assessed every 4 years using validated food frequency questionnaires. Three dietary patterns were evaluated: Western, Prudent, and the Alternative Healthy Eating Index-2010 (AHEI). Cox proportional hazard models estimated hazard ratios and 95% confidence intervals (CIs). RESULTS: Over 30 years of follow-up, 226 incident OCC cases were identified (124 in women and 102 in men). Among women, lower adherence to the Prudent and AHEI dietary patterns had higher OCC risk (HR for lowest vs. highest quartile, HR 1.86, 95% CI 1.03-3.35, and HR 2.17, 95% CI 1.24-3.77, respectively). Among non- or light-smoking and non- or light-drinking women, low adherence to the Prudent diet significantly increased OCC risk (HR for lowest vs. highest quartile 2.94, 95% CI 1.06-8.10). No associations were observed in men. Formal tests for interaction by sex were not statistically significant. CONCLUSIONS: Low adherence to Prudent and AHEI dietary patterns was associated with a higher risk of OCC in women but not men that warrants further investigation in larger pooled studies.