Sugar-sweetened soda consumption and risk of developing rheumatoid arthritis in women

Abstract

Background: Sugar-sweetened soda consumption is consistently associated with an increased risk of several chronic inflammatory diseases such as type 2 diabetes and cardiovascular diseases. Whether it plays a role in the development of rheumatoid arthritis (RA), a common autoimmune inflammatory disease, remains unclear.

Objective: The aim was to evaluate the association between sugar-sweetened soda consumption and risk of RA in US women.

Design: We prospectively followed 79,570 women from the Nurses' Health Study (NHS; 1980-2008) and 107,330 women from the NHS II (1991-2009). Information on sugar-sweetened soda consumption (including regular cola, caffeine-free cola, and other sugar-sweetened carbonated soda) was obtained from a validated food-frequency questionnaire at baseline and approximately every 4 y during follow-up. Incident RA cases were validated by medical record review. Time-varying Cox proportional hazards regression models were used to calculate HRs after adjustment for confounders. Results from both cohorts were pooled by an inverse-variance-weighted, fixed-effects model.

Results: During 3,381,268 person-years of follow-up, 857 incident cases of RA were documented in the 2 cohorts. In the multivariable pooled analyses, we found that women who consumed ≥1 serving of sugar-sweetened soda/d had a 63% (HR: 1.63; 95% CI: 1.15, 2.30; P-trend = 0.004) increased risk of developing seropositive RA compared with those who consumed no sugar-sweetened soda or who consumed <1 serving/mo. When we restricted analyses to those with later RA onset (after age 55 y) in the NHS, the association appeared to be stronger (HR: 2.64; 95% CI: 1.56, 4.46; P-trend < 0.0001). No significant association was found for sugar-sweetened soda and seronegative RA. Diet soda consumption was not significantly associated with risk of RA in the 2 cohorts.

Conclusion: Regular consumption of sugar-sweetened soda, but not diet soda, is associated with increased risk of seropositive RA in women, independent of other dietary and lifestyle factors.

FIGURE 1.

HRs for incident seropositive rheumatoid arthritis according to sugar-sweetened soda consumption in the Nurses’ Health Study (1980–2008) stratified by age at diagnosis of rheumatoid arthritis. HRs were calculated by using time-varying Cox proportional hazards models. Results were adjusted for age, census tract median family income (quartiles), cigarette smoking status (never; past; current, 1–14 cigarettes/d; or current, ≥15 cigarettes/d), alcohol consumption (<5.0, 5.0–15.0, or ≥15 g/d), age at menarche (<12, 12, or >12 y), parity and breastfeeding (nulliparous, parous/no breastfeeding, parous/1–12 mo breastfeeding, or parous/>12 mo breastfeeding), hormone use (premenopausal, postmenopausal with never use, current use, or past use), physical activity (0–2.9, 3–8.9, 9–17.9, 18–26.9, or ≥27 metabolic equivalent task hours/wk), BMI (in kg/m²; <20, 20–22.9, 23–24.9, 25–29.9, or ≥30), multivitamin use, Alternate Healthy Eating Index (quintiles), diabetes history, and total energy (kcal, quintiles). Reference category, <1 serving/mo.