Ultraprocessed Food Intake and Risk of Systemic Lupus Erythematosus Among Women Observed in the Nurses' Health Study...

We assessed ultraprocessed food (UPF) intake and systemic lupus erythematosus (SLE) incidence within the prospective Nurses' Health Study (NHS) cohorts.

A total of 204,175 women were observed (NHS 1984-2016; NHSII 1991-2017). Semiquantitative food frequency questionnaires were completed every two to four years. UPF intake was determined as per the Nova classification. Nurses self-reported new doctor-diagnosed SLE, confirmed by medical records. Time-varying Cox regressions estimated hazard ratios (HRs; 95% confidence intervals [CIs]) for patients with incident SLE and SLE by anti-double-stranded DNA (dsDNA) antibody at diagnosis, according to cumulatively updated daily (a) UPF servings, (b) total intake (in grams and milliliters), and (c) percentage of total intake. Analyses adjusted for age, race, cohort, caloric and alcohol intakes, household income, smoking, body mass index (BMI), physical activity, menarchal age, and oral contraceptive use. We tested for interaction with BMI and examined UPF categories.

Mean baseline age was ~50 years (NHS) and ~36 years (NHSII); 93% self-reported White race. A total of 212 patients with incident SLE were identified. SLE risk was higher in the third versus first UPF tertile (servings per day pooled multivariable [MV] HR 1.56, 95% CI 1.04-2.32; P = 0.03). Results were stronger for dsDNA antibody in patients with SLE (servings per day pooled MV HR 2.05, 95% CI 1.15-3.65; P = 0.01) and for absolute (servings or total) than percentage of total intake. Sugar-sweetened/artificially sweetened beverages were associated with SLE risk (third vs first tertile MV HR 1.45, 95% CI 1.01-2.09). No BMI interactions were observed.

Higher cumulative average daily UPF intake was associated with >50% increased SLE risk and with doubled risk for anti-dsDNA antibody in patients with SLE. Many deleterious effects on systemic inflammation and immunity are postulated.