The association between dietary patterns and a doctor diagnosis of systemic lupus erythematosus: the Adventist Health Study-2.

Objective: The aim of our study was to assess the association between a diagnosis of Systemic Lupus Erythematosus (SLE) and dietary pattern as well as demographic factors among subjects in the Adventist Health Study-2 (AHS-2) cohort.

Methods: Multivariable logistic regression modeling was used to assess the association between prevalence of self-reported SLE and dietary patterns (vegetarian, pesco-vegetarian and non-vegetarian). Potential confounding variables included were age, gender, race, education, and smoking history among 77,795 AHS-2 participants.

Results: There was a dose-response association between the prevalence of SLE with vegetarian diets, ordered by content of animal meats. The stricter vegetarians had 25% lower odds of reporting that they were currently being treated for SLE (OR = 0.75, 95% CI 0.56, 1.02) with intermediate levels for the pesco-vegetarians who eat fish (OR 0.88, 95% CI 0.57, 1.36), compared to non-vegetarians. As expected, there were also significant associations between the prevalence of SLE with sex, race, age, and smoking. Significantly fewer men were diagnosed with SLE compared to women (OR = 0.14, 95% CI: 0.08, 0.22). Compared to non-Hispanic Whites, non-Hispanic Blacks were significantly more likely to report a diagnosis of SLE (OR 1.69, 95% CI 1.29, 2.21). A significantly lower proportion of 30-39 year olds (OR 0.51, 95% CI 0.29, 0.90) reported a diagnosis of SLE when compared to those 60 or older. Also, ever smokers were more likely to report prevalent SLE than those who had never smoked (OR 1.71, 95% CI 1.27, 2.31).

Conclusion: We found that vegetarians had lower odds of doctor-diagnosed SLE with an increasing trend in prevalence from stricter vegetarians to pesco-vegetarians to non-vegetarians. We also note that the association with other demographic factors in AHS-2 was similar to that found in other studies. Future studies may focus on assessing the incidence and severity of the disease among vegetarians and non-vegetarians.