Association of dietary intake and serum concentration of omega-3 fatty acids on celiac disease: evidence from observational study and Mendelian randomization

Objective The association between omega-3 fatty acids (O3FA) and celiac disease lacks sufficient investigation. Methods Utilizing data gleaned from the 2009 to 2014 National Health and Nutrition Examination Survey (NHANES), this research comprises a sample of 13 403 adults, each aged 20 years and above. We conducted a multivariable logistic regression analysis to assess the association between dietary intake of O3FA and celiac disease. Subsequently, a two-sample Mendelian randomization was performed to estimate the unconfounded causal relationship between serum O3FA and celiac disease. The principal analytical strategy utilized the inverse-variance weighted methodology. Results In this cross-sectional study, 48 occurrences (0.36%) of celiac disease were encompassed. In the multivariable model, there was no association between dietary intake of O3FA and cases of celiac disease (odds ratio: 1.12, 95% confidence interval: 0.47–2.66, P = 0.792). However, serum levels of O3FA determined by genetic assay were correlated with celiac disease (inverse-variance weighted, β = 0.2439, P = 0.0287), with no evidence of horizontal pleiotropy ( P = 0.3689). Conclusion The dietary consumption of O3FA did not exhibit an association with the risk of celiac disease in this cross-sectional investigation. However, a correlation between celiac disease and serum levels of O3FA was observed in the Mendelian randomization. Further investigations, including human clinical trials, are warranted.