Anticariogenic Potential of Coffee in Adolescents: A Retrospective Exploratory Cohort Study

Background: Dental caries remains one of the most prevalent childhood diseases worldwide, with Streptococcus mutans playing a major etiological role. Coffee contains bioactive compounds, including chlorogenic acid and trigonelline, which have demonstrated antimicrobial and anticariogenic properties. Limited evidence exists on the preventive potential of coffee in Saudi adolescents. This study was designed to assess the benefits of coffee consumption in reducing dental caries among adolescents aged 12 to 16 years. Methods: A retrospective cohort study was conducted among 375 participants aged 12-16 years in Saudi Arabia. Participants were recruited from dental records and allocated into two cohorts: (1) consuming coffee at least twice weekly, subcategorized as sweetened versus unsweetened coffee consumers, and (2) non-coffee consumers. Clinical assessment included the Decayed, Missing, and Filled Teeth (DMFT) index, which was assessed at variable follow-up times up to 5 years. Caries increment (ΔDMFT) was compared using independent samples t-tests and one-way ANOVA with Tukey's post hoc tests. Multivariable linear regression adjusted for tooth brushing frequency, dietary habits, and oral hygiene status was performed. Results: Coffee consumers had significantly lower caries increment than non-consumers (0.78 ± 0.65 vs. 1.34 ± 0.88; mean difference -0.56; 95% CI -0.71 to -0.41; p < 0.001; Hedges' g = -0.71). Among coffee consumers, unsweetened coffee was associated with a lower increment than sweetened coffee (0.52 ± 0.48 vs. 1.09 ± 0.71; mean difference -0.57; 95% CI -0.76 to -0.38; p < 0.001) and non-consumers (mean difference -0.82; 95% CI -0.98 to -0.66; p < 0.001). After adjusting for oral hygiene and dietary factors, the protective associations remained significant for both unsweetened (adjusted mean difference -0.51; 95% CI -0.70 to -0.33; p < 0.001) and sweetened coffee (adjusted mean difference -0.22; 95% CI -0.41 to -0.04; p = 0.019). Conclusions: Within the limitations of this retrospective exploratory design, habitual coffee consumption, particularly that of unsweetened coffee, was associated with lower caries increment. These findings are hypothesis-generating and require confirmation in prospective studies with standardized exposure assessment and biological outcome measures.