Background
Studies have shown that personal diet has a certain impact on the development and treatment of rheumatoid arthritis (RA). However, the effect of overall dietary structure on RA is still an exploratory issue at present. Dietary inflammation index (DII) is an index that evaluates the inflammatory potential of the total nutrients consumed by human body. Therefore, we studied the correlation between DII and RA in Americans to explore whether the pro-inflammatory or anti-inflammatory effects of diet contribute to the risk of RA.
Methods
We used data from the 2005–2017 NHANES database for analysis, including 1819 individuals with RA and 8602 individuals without RA. Among them, DII was calculated by collecting the relevant data of Total Nutrient Intakes, First Day in the database. The analysis was carried out through the comparison between the two groups, including logical regression, multiple regression analysis, smooth curve fitting, recursive algorithm, and independent sample T-test.
Results
After adjusting for other confounding factors, we found that there was a positive correlation between DII and RA in Americans (β = 1.068, 95% CI = 1.026 to 1.111, P = 0.00121). In the subgroup analysis, it was found that characteristics of the participants were younger than 50 years old, female, Other Hispanic, BMI≥25 or federal poverty rate > 185%, there was still a positive association between DII and RA. Compared with non-smokers, the effect between DII and RA of smokers was greater than that of non-smokers. In Other Hispanic, there was an inflection point (K = 1.195). When K > 1.195, the curve gradient increases rapidly. In addition, the intake of energy, protein, dietary fiber, total saturated fatty acids, vitamin E, vitamin B6, magnesium, zinc, Niacin, Selenium, iron, and alcohol in individuals with RA was significantly lower than that in those without RA.
Conclusions
The inflammatory potential of diet may increase the risk of onset and development of RA. The risk may be different in different individuals, but it may be a feasible way to prevent and alleviate RA by improving dietary structure, reducing pro-inflammatory food, and increasing anti-inflammatory food intake.