Association between adjustable dietary factors and periodontitis: NHANES 2009–2014 and Mendelian randomization

Periodontitis is the major cause of tooth loss in adults and one of the most common non-communicable diseases. Clinically, periodontitis impairs oral health and associated with various systemic diseases. Maintaining a healthy diet is considered risk reduction of periodontitis. To explore the causal effect between dietary data and periodontitis by Mendelian randomization (MR) analyses. A total of 11,704 participants and 21 dietary variables from the NHANES were in random forest to rank the importance in predicting periodontitis. Data were from the genome wide association studies (GWASs) database to estimate causal relationships between diet data and periodontitis. Two-sample MR analyses were conducted by using the inverse-variance weighted (IVW) method. The MR showed alcohol consumption and sugars intake increased the risk of chronic periodontitis with odds ratio (OR) 2.768 (95% CI: 1.03e + 00–7.42e + 00) and 2.123 (95% CI: 1.06e + 00–4.26e + 00) respectively. Vitamins and minerals, including folic acid and folate, magnesium, vitamin A, vitamin E, vitamin C, calcium, vitamin D and zinc, were not causally associated with chronic periodontitis. Alcohol consumption greater than 2.5 drinks per day and sugar intake more than 4.88 g increased the risk of periodontitis, with a calculated relative risk of 1.33 and 1.61, respectively. It is suggested to drink alcohol less than 2.5 drinks/day and consume sugar less than 4.88 g/day to avoid alcohol and sugar consumption promoting the development of periodontitis. Establishing a dietary pattern conducive to periodontal health may be the focus of further clinical research.