Background The Mediterranean diet suppresses the disease activity of rheumatoid arthritis (RA). However, the key elements involved in this effect have not been assessed.

Objectives To clarify the relationship between disease activity in patients with RA and Mediterranean diet scores calculated from daily food and specific nutrient components.

Methods Data from 208 consecutive patients with RA and 205 age- and gender-matched healthy volunteers participating in a 10-year-prospective cohort study (TOMORROW) that started in 2010 were assessed (UMIN000003876). We performed a cross-sectional, retrospective analysis of baseline and 2011 data. Daily food and nutrient intake status were assessed using a brief-type self-administered diet history questionnaire (BDHQ) and Mediterranean diet scores were calculated from reference results from the control group. Disease activity was calculated using disease activity scores in 28 joints based on erythrocyte sedimentation rates (DAS28-ESR).

Results The intake of monounsaturated fatty acids (MUFA) and of Mediterranean diet components was significantly lower in the RA than in the control group (p =0.003). The ratio of MUFA to saturated FA (SFA) was significantly lower; and intake of fruits, tubers and roots were significantly higher in patients with RA with high disease activity than in those in remission and with low disease activity (p =0.033, 0.010, 0.047, respectively). The DAS28-ESR and MUFA/SFA values revealed a significant correlation, even after age adjustment (R = -0.228, p <0.01). We clarified these findings using logistic regression analysis. Components of Mediterranean diet scores were categorized according to the median intake based on control food and nutrient intake status, and the DAS28-ESR values were categorized as remission or active disease. Intake of MUFA was an independent predictor of remission in patients with RA (Odds: 0.51; 95% CI =0.25–1.02, p=0.057). Annual changes in DAS28-ESR values between 2010 and 2011 significantly correlated with the MUFA/SFA ratio during 2011 even after age adjustment (R =0.180, p =0.01).

Conclusions The daily intake of MUFA, a component of the Mediterranean diet, might suppress disease activity in patients with RA.

Disclosure of Interest Y. Matsumoto: None declared, Y. Sugioka: None declared, M. Tada: None declared, T. Okano: None declared, K. Mamoto: None declared, K. Inui: None declared, D. Habu: None declared, T. Koike Grant/research support: Takeda Pharmaceutical, Mitsubishi Tanabe Pharma Corporation, Chugai Pharmaceutical, Eisai, Abbvie, Teijin Pharma, MSD and Ono Pharmaceutical, Speakers bureau: Takeda Pharmaceutical, Mitsubishi Tanabe Pharma Corporation, Chugai Pharmaceutical, Eisai, Abbvie, Teijin Pharma, MSD and Ono Pharmaceutical

DOI 10.1136/annrheumdis-2014-eular.3937