Association between dietary inflammatory index and the risk of oral cancer in the southeast of China

Background/objectives To evaluate the role of the potential inflammatory effects of diet using the Energy adjusted Dietary Inflammatory Index (E-DII) for oral cancer. Subjects/methods A case-control study including 295 oral cancer cases and 425 controls from September 2010 to June 2018 was performed in Fujian Province, China. The E-DII was calculated based on the food frequency questionnaire (FFQ) and adjusted by total energy intake. The association between E-DII and the risk of oral cancer was estimated with unconditional logistic regression model. Results Compared with E-DII score in the lowest quartile, those with E-DII score in the fourth quartile were at the higher risk of oral cancer (OR = 2.57; 95% CI: 1.54, 4.29,P-trend = 0.013). When analyses were carried out using E-DII as a continuous variable, one-unit increase in E-DII increased the odds of having oral cancer by 3% (95% CI: 1.00, 1.06). Moreover, there was a significant interaction between the E-DII and oral hygiene for oral cancer (P-interaction < 0.001, in those without and with poor hygiene, the OR (95% CI) were 1.96 (0.96, 4.00) and 4.23 (1.83, 9.81), respectively). Conclusions The present study suggests that the higher E-DII score, indicated a pro-inflammatory diet, may be a risk factor for oral cancer in southeast of China. More large samples and prospective studies need to validate our results and explore the prevention strategies of oral cancer via changing dietary habits.