@article {Hu1357, author = {Yang Hu and Jeffrey A Sparks and Susan Malspeis and Karen H Costenbader and Frank B Hu and Elizabeth W Karlson and Bing Lu}, title = {Long-term dietary quality and risk of developing rheumatoid arthritis in women}, volume = {76}, number = {8}, pages = {1357--1364}, year = {2017}, doi = {10.1136/annrheumdis-2016-210431}, publisher = {BMJ Publishing Group Ltd}, abstract = {Objectives To evaluate the association between long-term dietary quality, measured by the 2010 Alternative Healthy Eating Index, and risk of rheumatoid arthritis (RA) in women.Methods We prospectively followed 76 597 women in the Nurses{\textquoteright} Health Study aged 30{\textendash}55 years and 93 392 women in the Nurses{\textquoteright} Health Study II aged 25{\textendash}42 years at baseline and free from RA or other connective tissue diseases. The lifestyle, environmental exposure and anthropometric information were collected at baseline and updated biennially. Cumulative follow-up rates were more than 90\% for both cohorts. The primary outcome was RA alone with two subtypes of the disease: seropositive and seronegative RA.Results During 3 678 104 person-years, 1007 RA cases were confirmed. In the multivariable-adjusted model, long-term adherence to healthy eating patterns was marginally associated with reduced RA risk. To assess potential effect modification by age at diagnosis, we stratified by age. Among women aged <=55 years, better quality diet was associated with lower RA risk (HRQ4 vs Q1: 0.67; 95\% CI 0.51 to 0.88; p trend: 0.002), but no significant association was found for women aged \>55 years (p interaction: 0.005). When stratifying by serostatus, the inverse association among those aged <=55 years was strongest for seropositive RA (HRQ4 vs Q1: 0.60; 95\% CI 0.42 to 0.86; p trend: 0.003).Conclusions A healthier diet was associated with a reduced risk of RA occurring at 55 years of age or younger, particularly seropositive RA.}, issn = {0003-4967}, URL = {https://ard.bmj.com/content/76/8/1357}, eprint = {https://ard.bmj.com/content/76/8/1357.full.pdf}, journal = {Annals of the Rheumatic Diseases} }