Association between the quality of plant-based diets and periodontitis in the US general population

AIM: This study investigated the relationships of plant-based diet indices with periodontitis and serum IgG antibodies against periodontopathogens in the US population. MATERIALS AND METHODS: This study analyzed cross-sectional data on 5,651 participants ≥40 years of age from the Third National Health and Nutrition Examination Survey. Food frequency questionnaire data were used to calculate the overall plant-based diet index (PDI), healthful plant-based diet index (hPDI), and unhealthful plant-based diet index (uPDI). Periodontitis was defined using a half-reduced CDC/AAP (Centers for Disease Control and Prevention and American Academy of Periodontology) case definition. Serum antibodies against 19 periodontopathogens were used to classify the population into two subgroups using hierarchical clustering. Survey-weighted multivariable logistic regressions were applied to assess the associations of PDI/hPDI/uPDI z-scores with periodontitis and hierarchical clusters after adjusting for potential confounders. RESULTS: A total of 2,841 (50.3) participants were defined as having moderate/severe periodontitis. Overall PDI z-score was not significantly associated with the clinical and bacterial markers of periodontitis. By considering the healthiness of plant foods, we observed an inverse association between hPDI z-score and periodontitis (odds ratio [OR] = 0.925, 95% confidence interval = 0.860 to 0.995). In contrast, higher uPDI z-score (adherence to unhealthful plant foods) might increase the risk of periodontitis (OR = 1.100, 1.043 to 1.161). Regarding antibodies against periodontopathogens, the participants in cluster 2 had higher periodontal antibodies than those in cluster 1. The hPDI z-score was positively associated with cluster 2 (OR = 1.192, 1.112 to 1.278). In contrast, an inverse association between uPDI z-score and cluster 2 was found (OR = 0.834, 0.775 to 0.896). CONCLUSION: Plant-based diets were associated with periodontitis, depending on their quality. A healthy plant-based diet was inversely related to an increased risk of periodontitis but positively related to elevated antibody levels against periodontopathogens. For an unhealthy plant-based diet, the opposite trends were observed. This article is protected by copyright. All rights reserved