The alcohol harm paradox and tooth loss among Brazilian older adults

Objective: To investigate whether the association between alcohol consumption and tooth loss is modified across socioeconomic positions (SEPs) in Brazilian older adults.Methods: We conducted a secondary analysis using data of The Brazilian Longitudinal Study of Ageing (ELSI-Brazil 2015- 2016). Effect Measure Modification (EMM) analyses using multivariable Poisson regression models tested whether the association be-tween heavy drinking and lack of functional dentition (FD) varies in magnitude and direction according to levels of Household Wealth index (HWI) and educational attainment, assessed by the Relative Excess Risk due to Interaction (RERI). Sensitivity analyses using lifetime exposure to alcohol were performed.Results: The analytical sample comprised 8078 participants. Heavy drinkers living in low-wealth households and with lower education presented 7% (95% CI: 1.01- 1.14) and 36% (95% CI: 1.28- 1.44) higher prevalence of lack of FD, respectively, than their counterparts, and super-additive associations were detected [RERI for HWI: 0.12 (95% CI: 0.02- 0.21); RERI for educational attainment: 0.20 (95% CI: 0.09- 0.30)]. The associations were also super-additive in the sensitivity analyses when controlling for abstainer reference group bias.Conclusion: We suggest that alcohol consumption disproportionately impacts the prevalence of tooth loss in Brazilian older adults from lower SEP groups.