Association Between Inflammatory Diet and Oral Diseases: Results from the 2015-2018 National Health and Nutrition Examination Survey

Abstract

Objective The link between diet and oral health is well-established, yet the role of inflammation in this relationship has been underexplored. This study investigates the association between the energy-adjusted Dietary Inflammatory Index (E-DII) and various oral health outcomes including caries prevalence, missing teeth, and overall caries experience, while accounting for demographic and behavioral factors using data from the 2015–2018 National Health and Nutrition Examination Survey (NHANES). Materials and Methods Dental outcomes assessed included active untreated caries, measured as the number and prevalence of: coronal and root caries; and number of missing teeth due to caries or periodontal disease complete edentulism; and overall caries experience measured by the DMFT index, which quantifies decayed, missing, and filled teeth. Logistic regression and Poisson regression models were used to evaluate associations between E-DII and oral health outcomes, adjusting for age, race, gender, education, income, smoking status, and time since last dental visit. Sensitivity analyses were conducted to assess the robustness of the findings by modifying the E-DII and applying different analytical approaches. Results The analysis included 8,131 U.S. adults aged 20 years or older who had completed dental examinations and two-day dietary recalls, representing a weighted population of approximately 231 million adults. Participants were categorized into quartiles based on their E-DII score, with higher scores indicating a more pro-inflammatory diet. The distribution of E-DII quartiles varied by demographic factors. Higher E-DII scores were associated with lower education and income levels. More than one-third of non-Hispanic Black adults (34.4%) were in the highest E-DII quartile, whereas 43.2% of non-Hispanic Asians were in the lowest quartile. A higher proportion of current smokers and individuals without recent dental visits were also in the highest E-DII quartile. Higher E-DII quartiles were significantly associated with poorer oral health outcomes. Individuals in the highest E-DII quartile had greater odds of experiencing coronal caries (adjusted OR: 2.17, 95% CI: 1.62–2.91), root caries (adjusted OR: 2.10, 95% CI: 1.37–3.22), and missing teeth (adjusted OR: 1.53, 95% CI: 1.13–2.06) compared to those in the lowest quartile. The mean number of decayed teeth increased progressively with higher E-DII quartiles, with an adjusted mean ratio of 1.79 (95% CI: 1.29–2.47) for the highest quartile. Sensitivity analyses, including a modified E-DII that excluded carbohydrates and alcohol, confirmed these associations. Further analysis using a binary classification of E-DII and continuous modeling supported the relationship between pro-inflammatory diets and poor oral health. Each unit increase in continuous E-DII was associated with increased odds of coronal caries (adjusted OR: 1.30, 95% CI: 1.16–1.44) and missing teeth (adjusted OR: 1.16, 95% CI: 1.05–1.27). Conclusion This study highlights the significant impact of pro-inflammatory diets on oral health. A higher E-DII, indicating a more inflammatory diet, was consistently associated with worse oral health outcomes, including greater odds of coronal and root caries, missing teeth, and a higher number of decayed teeth. These findings suggest that dietary modifications could serve as a potential strategy for preventing oral diseases and improving overall oral health.