Background The immunomodulatory and anti-inflammatory effects of the Mediterranean Diet (MedDiet) suggest a protective role in rheumatic conditions¹. A small but increasing body of evidence from randomised controlled trials demonstrates that increased adherence to a MedDiet in patients with Rheumatoid Arthritis (RA) can have a beneficial effect on disease activity, pain levels and physical function².

Objectives The primary aim of the MEDRA study was to determine the effects of a MedDiet compared to the current food based dietary guidelines in Ireland (Healthy Eating Guidelines/HEG) on the physical function and quality of life in patients with RA.

Methods In this randomised controlled trial, 44 patients with RA were randomly allocated to either the MedDiet or the HEG arm of the study. The 12-week dietary intervention study was delivered online by a Registered Dietitian (RD) and included data collection at three time points: baseline, mid-intervention (6 weeks) and post-intervention (12 weeks). Participants in both dietary intervention groups attended three video consultations with the RD, at baseline, weeks 6 and 12, and two follow up reviews by telephone at weeks 3 and 9. All participants were provided resources designed to specifically explain the assigned diet and how it can be successfully adhered to. Primary outcomes were changes in physical function and quality of life measured using the validated Health Assessment Questionnaire - Disability Index (HAQ-DI) and Rheumatoid Arthritis Quality of Life Questionnaire (RAQoL), respectively. Secondary outcomes included changes in physical activity and patient-reported pain levels.

Results Forty patients with RA completed the study (mean age:47.5 SD10.9 years, females: 87.5%). No significant differences were found in the distribution of age, anthropometric measures, disease duration, physical activity, and quality of life between the two diet groups at baseline. However, the group assigned to the MedDiet had better mean values for quality of life compared to the HEG group; 0.9 ± 0.5 vs. 1.4 ±0.7, p<0.001, respectfully. Compared to baseline, there was a significant improvement in HAQ-DI scores in participants following both the MedDiet (0.9 ±0.5 to 0.5 ± 0.4, p<0.001) and HEG (1.4 ± 0.7 to 1.0 ± 0.6, p<0.001). Significant improvements in RAQoL scores were also seen in both the MedDiet (10.1 ±7.5 to 4.0 ± 4.7, p<0.001) and HEG (11.25 ± 7.2 to 7.9 ± 6.4, p=0.02) groups. At 12 weeks, participants in the MedDiet group reported a significantly better physical function status (mean difference -0.5, 95% CI -0.8 to -0.1, p=0.007) and quality of life (mean difference -3.9, 95% CI -7.5 to -0.2, p=0.04) compared to the HEG group. Participants in the MedDiet group demonstrated a significant increase in physical activity levels (56.7 ± 28.6 to 70.6 ± 33.5, p=0.01). Conversely, a non-significant decrease in physical activity levels was observed in the HEG group from baseline to post-intervention.

Conclusion The study indicates positive effects of a Mediterranean and low-fat diet as per the Healthy Eating Guidelines on physical function and quality of life in patients with RA. The MedDiet may be superior in improving physical activity levels. Further studies and a larger cohort are needed to confirm these findings.

References [1]Oliviero, F., Spinella, P., Fiocco, U., Ramonda, R., Sfriso, P. and Punzi, L., 2015. How the Mediterranean diet and some of its components modulate inflammatory pathways in arthritis. Swiss medical weekly, 145(4546).

[2]Forsyth, C., Kouvari, M., D’Cunha, N.M., Georgousopoulou, E.N., Panagiotakos, D.B., Mellor, D.D., Kellett, J. and Naumovski, N., 2018. The effects of the Mediterranean diet on rheumatoid arthritis prevention and treatment: a systematic review of human prospective studies. Rheumatology international, 38(5), pp.737-747.

Acknowledgements This work was funded by the School of Allied Health Postgraduate scholarship at the University of Limerick.

Disclosure of Interests None declared