Long-term dietary quality and risk of developing rheumatoid arthritis in women

Ann Rheum Dis. 2017 Aug;76(8):1357-1364. doi: 10.1136/annrheumdis-2016-210431. Epub 2017 Jan 30.

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' 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.

Keywords: Ant-CCP; Epidemiology; Rheumatoid Arthritis.

MeSH terms

  • Adult
  • Arthritis, Rheumatoid / epidemiology*
  • Arthritis, Rheumatoid / immunology
  • Cohort Studies
  • Diet / statistics & numerical data
  • Diet, Healthy / statistics & numerical data*
  • Environmental Exposure
  • Female
  • Humans
  • Life Style
  • Longitudinal Studies
  • Middle Aged
  • Multivariate Analysis
  • Proportional Hazards Models
  • Prospective Studies
  • Rheumatoid Factor / immunology
  • Risk Factors

Substances

  • Rheumatoid Factor