title: Long-term dietary quality and risk of developing rheumatoid arthritis in women.
abstract: OBJECTIVE
  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' Health Study aged 30-55 years and 93 392 women in the Nurses' Health Study II aged 25-42 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.
authors.affiliation: Department of Nutrition, Harvard TH Chan School of Public Health, Boston, Massachusetts, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Hu
authors.affiliation: Division of Rheumatology, Immunology and Allergy, Brigham & Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Jeffrey A
authors.initials: JA
authors.lastname: Sparks
authors.affiliation: Division of Rheumatology, Immunology and Allergy, Brigham & Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Susan
authors.initials: S
authors.lastname: Malspeis
authors.affiliation: Division of Rheumatology, Immunology and Allergy, Brigham & Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Karen H
authors.initials: KH
authors.lastname: Costenbader
authors.affiliation: Departments of Nutrition and Epidemiology, Harvard TH Chan School of Public Health, Boston, Massachusetts, USA.|Channing Division of Network Medicine, Brigham & Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Frank B
authors.initials: FB
authors.lastname: Hu
authors.affiliation: Division of Rheumatology, Immunology and Allergy, Brigham & Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Elizabeth W
authors.initials: EW
authors.lastname: Karlson
authors.affiliation: Division of Rheumatology, Immunology and Allergy, Brigham & Women's Hospital and Harvard Medical School, Boston, Massachusetts, USA.
authors.forename: Bing
authors.initials: B
authors.lastname: Lu
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000453:epidemiology* / Q000276:immunology; D015331:Cohort Studies; D004032:Diet / Q000706:statistics & numerical data; D000072001:Diet, Healthy / Q000706:statistics & numerical data*; D004781:Environmental Exposure; D005260:Female; D006801:Humans; D008019:Life Style; D008137:Longitudinal Studies; D008875:Middle Aged; D015999:Multivariate Analysis; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012217:Rheumatoid Factor / Q000276:immunology; D012307:Risk Factors
chemical_list: D012217:Rheumatoid Factor
keywords: Ant-CCP; Epidemiology; Rheumatoid Arthritis