Knowledge remains scarce regarding diet and SLE risk. We investigated four dietary quality scores and SLE risk overall and anti‐dsDNA positive (+) versus negative (‐) subtypes. We studied 79,568 women in the Nurses’ Health Study (NHS, 1984‐2014) and 93,554 in the NHSII (1991‐2013). Using validated food frequency questionnaires, we calculated four dietary scores:

  • the 2010 Alternative Healthy Eating Index [AHEI‐2010]
  • Alternative Mediterranean Diet Score (1)
  • Dietary Approach to Stop Hypertension [DASH]
  • Empirical Dietary Inflammatory Pattern [EDIP]

Incident SLE was confirmed by a medical record review. Time‐varying Cox regression models estimated pooled hazard ratios (HRs [95% confidence intervals]) of SLE risk, overall and by anti‐dsDNA, for cumulative average dietary quality score tertiles and individual AHEI‐2010 components.

We identified 194 incident SLE cases. SLE risk was similar in women with the highest (vs. lowest) dietary scores (AHEI‐2010: HR 0.78 [95% CI 0.54‐1.14], aMed: HR 0.82 [95% CI 0.56‐1.18], DASH: HR 1.16 [95% CI 0.81‐1.66], EDIP: HR 0.83 [95% CI 0.57‐1.21]). No association was demonstrated for dsDNA+ or dsDNA‐ SLE risk. Women in the highest (vs. lowest) AHEI‐2010 tertile of nut/legume intake had a decreased SLE risk (HR 0.59 [95% CI 0.40‐0.87]). No association was demonstrated for other AHEI‐2010 components and SLE risk.

We observed no association between long‐term adherence to the AHEI‐2010, aMed, DASH, or EDIP scores with SLE risk, suggesting a large effect of dietary quality on SLE risk is unlikely. However, the potential reduction in overall SLE risk with high nut/legume intake warrants further investigation.