A pro-inflammatory diet is associated with an increased odds of periodontitis: finding from a case–control study

OBJECTIVE: This study aimed to evaluate the inflammatory effect of diet using the dietary Inflammatory Index (DII) on the odds of periodontitis. We hypothesized that a diet with high DII scores (a pro-inflammatory diet) is associated with high chronic and systematic inflammation resulting in periodontitis. Periodontitis is one of the most common inflammatory diseases that affect the tissues around the tooth and results from the interaction of bacterial infection and the host immune response. The DII shows the association between different food components and the level of specific inflammatory biomarkers. METHOD: The food intake of 87 cases with diagnosed periodontitis and 87 control was assessed using a 163-item valid food frequency questionnaire (FFQ). The DII was calculated based on the FFQ data. Logistic and linear regression models adjusting for multivariable confounders were used to investigate the odds ratio (OR) and 95% confidence intervals (CI) of developing periodontitis. RESULTS: There was a significant difference between the mean intake of micronutrients and food groups, including saturated fatty acids (SFAs), iron, magnesium, manganese, vitamin C, crude fiber, selenium, chromium, whole fiber, caffeine, dairy, and meat, between patients with periodontitis and the control group (p-value˂0.05). DII scores in this study ranged from -3.13 to + 0.99. However, the periodontitis OR in the raw and multivariable-adjusted models was not statistically significant (multivariable-adjusted OR (tertiles 1 vs. tertiles 3) = 2.00, 95%CI: 0.4–90.42, p-value = 0.08). A similar result was also observed in the continuous model of DII (multivariable-adjusted OR (DII continuous) = 1.93, 95%CI: 0.30–98.79, p-value = 0.05). CONCLUSION: Although the OR was not statistically significant in crude models, a significant trend was found in multivariable-adjusted models. The results were promising since this is the first study to examine the association between diet-induced inflammation and dental disease. It is advisable to conduct additional studies with high sample sizes and other designs, such as prospective studies. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s40795-023-00760-7.