Dietary polyunsaturated fatty acid protective against rheumatoid arthritis

Dietary intake of polyunsaturated fatty acids (PUFAs) helps reduce the risk of rheumatoid arthritis (RA), as reported in a study.

For the study, researchers looked at 188,597 participants in the UK Biobank who were free of RA at baseline. Cox proportional hazard models were used to assess the association of PUFA intake with RA. Polygenic risk score for RA allowed evaluation of how genetic predisposition might modify such an association.

Protein signatures associated with PUFAs intakes and RA risk were identified using Olink proteomics. Additionally, mediation analyses were conducted to evaluate specific proteins as potential mediators.

Over a median follow-up of 9.1 years, 1,640 cases of RA were reported. PUFA intake showed a protective association with RA risk. Each one-standard deviation increase in the intakes of stearidonic acid (SDA), eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA) was associated with a risk reduction of between 9 percent and 10 percent.

Among individuals with high genetic risk, n-3 PUFAs intakes (including SDA, EPA, DPA, and DHA) were associated with significantly reduced RA risk, with antagonistic additive interactions against genetic predisposition.

Olink-based proteomic analysis indicated that RA risk and specific n-3 PUFAs intakes (DHA, DPA, and SDA) had primary connections to immune response and inflammation, cytokine interactions, signal transduction, cell adhesion and migration, and metabolic pathways.

Mediation analyses identified 55 mediating proteins involved in processes such as immune regulation, inflammation, and cell homeostasis. Among these proteins, CD80 and TNFRSF4 stood out as important mediators in the relationship between specific n-3 PUFA intakes and RA risk.