Is dietary pattern a mediator of the relationship between socioeconomic status and dental caries?

To investigate whether a healthy diet and added sugar mediate the relationship between socioeconomic status and oral health status in adults.

This is a secondary cross-sectional analysis of adult participants from the 2015-2016 National Health and Nutrition Examination Survey from the United States (n=3367). Structural equation modeling tested direct and indirect pathways from a latent variable for socioeconomic status to oral health via healthy eating (Health Eating Index) and added sugar in a multiple-mediator multiple-outcome model.

Added sugar was directly associated with untreated dental caries [Standardized coefficient (SC)=0.10], and healthy eating was directly associated with both untreated dental caries (SC=-0.11) and tooth loss (SC=-0.05). Higher socioeconomic status was associated with lower untreated dental caries through direct (SC =-0.246) and small indirect paths via healthy diet (SC= -0.026), lower consumption of added sugar (SC=-0.007), and dental visits (SC=-0.162). Higher socioeconomic status was associated with fewer teeth lost through direct (SC =-0.306) and very small indirect paths via healthy diet (SC=-0.016), added sugar consumption (SC=-0.001), and untreated dental caries (SC=-0.094).

Both socioeconomic status and dietary pattern independently contributed to tooth loss and dental caries. The contribution of dietary factors as a mediator to socioeconomic inequities in oral health was small, and statistically significant.

A systems approach to socioeconomic inequities in oral health takes into account the complex relationships between socioeconomics, dietary patterns, oral health and health. Socioeconomic conditions and nutrition, as common risk factors to noncommunicable disorders, should be tackled in programs to improve oral health.