Nutritional Determinants of Oral Cancer: A Global Population Attributable Fraction Analysis Across 185 Countries (1990–2018)

Oral cancer causes approximately 390,000 new cases and 188,000 deaths annually, with substantial functional impairment affecting quality of life. Although dietary associations have been recognised, the nutrition-attributable burden at the population level remains inadequately quantified globally, particularly regarding age-, sex- and region-specific patterns. We estimated population attributable fractions (PAFs) for 7 nutritional determinants across 185 countries from 1990 to 2018 using the Global Dietary Database and Global Burden of Disease data. A comparative risk assessment methodology with log-linear dose-response models quantified disease burden attributable to suboptimal dietary intake. Stratified analyses examined sex-specific, age-specific and regional variations. Sensitivity analyses were conducted using relative risk variation analysis, model specification comparison and bootstrap uncertainty analysis. In 2018, fruits (−39.0%), vegetables (−38.8%) and vitamin B9 (−36.5%) exhibited the highest protective PAFs, while sugar-sweetened beverages (+36.1%) demonstrated the greatest harmful impact. The global incidence increased by 56%, despite improvements in protective factors, concurrent with a 37% increase in sugar-sweetened beverage consumption. Males consistently displayed higher PAFs than females across most nutrients (fruits: P = .004; vitamin C: P < .001; processed meats: P < .001), paralleling their 1.9-fold higher global incidence of oral cancer (5.4 vs 2.8 per 100,000). Regional PAF disparities corresponded with cancer-burden patterns: Latin America exhibited the highest sugar-sweetened beverage PAF (+40%) alongside elevated incidence rates (5.5 per 100,000), while South Asia exhibited the greatest vitamin B9 inadequacy (−40%) concurrent with a high regional burden (7.3 per 100,000 in males). Age-gradient analysis revealed that sugar-sweetened beverages disproportionately affected younger age groups (25-29 years: PAF +37.8% vs 75-79 years: PAF +28.9%). However, absolute incidence rates increased with age, reflecting the cumulative nature of cancer risk. Sensitivity analyses confirmed robust estimates (CV: 0.0023-0.0158). Insufficient intake of fruits (−154.9 g/d), vegetables (−211.9 g/d), vitamin B9 (−449.0 μg/d) and excess sugar-sweetened beverages (+180.1 mL/d) are the predominant modifiable risks. Nonlinear patterns and synergistic interactions suggest the need for multicomponent, region-specific interventions.