Background The role of nutrition in the pathogenesis of RA has been suggested in many studies but remains controversial.

Objectives To assess the relationship between consumption of the most frequently drinked specific beverages (coffee, tea, alcohol, and soft drinks) and the risk of RA.

Methods The E3N Study (Étude Épidémiologique auprès des femmes de la Mutuelle Générale de l’Éducation Nationale) is a French prospective cohort including 98,995 women since 1990. RA cases have been previously identified with specific questionnaires and medication reimbursement database (1). Food and beverage consumption was assessed using a validated food-frequency questionnaire. Hazard ratios (HR) and their 95% confidence intervals (CI) for incident RA were estimated by Cox proportional hazards models, adjusted for age and the main potential confounders, including smoking. Tests for linear trends were performed. As smoking is a major risk factor for RA, stratified analyses were conducted according to the smoking status (ever or never-smoker) even in the absence of statistically significant interaction between the smoking status and beverage consumptions. Sensitivity analyses were performed in the subgroup of seropositive cases (positive RF and/or ACPA).

Results During a total follow-up of 21 years (mean 20.78 (SD 2.26) years), 62,630 women contributed 1,300,874 person-years, and 481 developed RA (incidence 37/100 000 person-years). Incident RA cases were diagnosed a mean 11.7 (SD 5.9) years after baseline. Of the 179 (37.2%) RA cases with known antibody status, 153 (31.8%) were seropositive. Consumptions of total alcohol, tea and sugar-sweetened soft drinks were not associated with RA risk. Coffee consumption was associated with RA risk with a dose-effect relationship (≥4 cups/day versus ≤ 1cup/day, HR 1.24, 95% CI [0.94; 1.64], p_trend = 0.04), only in never-smokers. According to the type of coffee consumed, only high caffeinated coffee consumption was associated with an increased risk of RA among never-smokers (≥ 3.5 cups/day versus ≤ 1 cup/day, HR=1.62 95% CI [1.12;2.34], p_trend = 0.006, p_interaction = 0.07). Decaffeinated coffee consumption was not associated with RA risk. Risk of RA was higher with artificially-sweetened soft-drinks consumption (consumers versus non-consumers, HR 1.66 [1.12; 2.45]), in never-smokers. No association was observed with other soft drinks. Moderate liquor (spirits or aperitifs) intake was associated with a reduced risk of RA among ever-smokers (consumption of 1 - 3 glasses/week versus non-consumers HR 0.63, 95% CI [0.43; 0.91]) and moderate wine consumption was associated with a decreased risk of seropositive RA (consumption of 4 -10 glasses/week versus ≤ 1glass/week HR 0.57, 95% CI [0.35 to 0.94], whereas no association was observed with other alcohols.

Conclusion Consumptions of tea, total alcohol, and sugar-sweetened soft drinks were not associated with RA risk, whereas consumptions of coffee (especially caffeinated coffee), and artificially-sweetened soft drinks were associated with higher RA risk, among never-smokers. By contrast, moderate liquor consumption was associated with a decreased risk of RA in ever-smokers, and moderate wine consumption was associated with a decreased risk of seropositive RA. If further confirmed, these results could lead to novel mechanistic hypotheses and to simple prevention measures.

References [1]Nguyen Y, Salliot C, Gusto G, Descamps E, Mariette X, Boutron-Ruault M-C, et al. Improving accuracy of self-reported diagnoses of rheumatoid arthritis in the French prospective E3N-EPIC cohort: a validation study. BMJ Open. d caffeinated coffee),

Acknowledgements The authors would like to thank Pascale Gerbouin-Rerolle, Mariam Alyaniakian, Sofiane Harizi and Roselyn Rima Gomes for their help on data management. The present work was performed using data from the Inserm E3N cohort and support from the MGEN, Gustave Roussy, and the Ligue contre le Cancer for setting up and maintaining the cohort. The cohort was supported by a state grant ANR-10-COHO-0006 from the Agence Nationale de la Recherche within the Investissement d’Avenir program.The present work was conducted thanks to a research grant from the Société Française de Rhumatologie.

Disclosure of Interests None declared