The association between polyunsaturated fatty acids and periodontitis: NHANES 2011–2014 and Mendelian randomisation analysis

Abstract Background We aimed to explore the association and potential causality between polyunsaturated fatty acids concentrations and the risk of periodontal disease. Materials and methods Data were collected from the 2011–2014 National Health and Nutrition Examination Survey (NHANES). Weighted logistic regression analysis and restricted cubic spline (RCS) analysis were used to analyse the associations of the concentrations of omega-3 and omega-6 fatty acids and the omega-6/omega-3 fatty acids ratio with the risk of periodontitis. E-value and propensity score matching (PSM) analyses were used for sensitivity analyses. In addition, two-sample Mendelian randomisation (MR) analyses were performed to assess the potential causal impact of the concentrations of those fatty acids on periodontitis risk. Results A total of 2462 participants from the NHANES were included. Logistic regression analysis revealed that high omega-3 fatty acids levels were negatively associated with the risk of developing periodontitis ( P < 0.05), while the omega-6/omega-3 fatty acids ratio was positively associated with the risk of developing periodontitis ( P < 0.05). There was no significant association between omega-6 concentrations and the risk of periodontitis. The findings mentioned above were confirmed by analysis following a 1:1 PSM. Furthermore, MR examination of the two samples indicated no possible causal link between the risk of periodontitis and the concentrations of omega-3 or omega-6 fatty acids or the ratio of omega-6 to omega-3 fatty acids ( P > 0.05). Conclusion Although omega-3 fatty acids and the omega-6/omega-3 fatty acids ratio were associated with the risk of periodontitis in cross-sectional studies, the MR results did not support a causal relationship between them. Therefore, there is no indication that an increase in the omega-3 fatty acids concentration or a decrease in the omega-6/omega-3 fatty acids ratio may be beneficial for preventing periodontitis.