In a new study entitled “Dietary supplementation with arachidonic acid increases arachidonic acid content in paw, but does not affect arthritis severity or prostaglandin E2 content in rat adjuvant-induced arthritis model” authors evaluated, in a rat model of arthritis, the impact of dietary intake of arachidonic acid on both rheumatoid arthritis severity and lipid content in affected tissues. The study was published in the journal Lipids in Health and Disease.
Rheumatoid arthritis is a chronic inflammatory disease affecting the lining of the joints, the synovial membrane, but can also affect other organs. The disease is a type of autoimmune disorder, wherein the body’s own immune system attacks its own body tissues. As a result, the inflamed joint tissue causes erosion of both cartilage and bone, leading to joint deformities. The disorder is manifested by painful symptoms of swelling and redness in the joints. It is estimated that 1.5 million people in The United States suffer from Rheumatoid arthritis, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS).
The treatment for Rheumatoid arthritis currently relies on the administration of biologic therapy; however, previous treatment approaches included the use of non-steroidal anti-inflammatory drugs (NSAIDs) and cyclooxygenase (COX) inhibitors. These drugs targeted the activity of cyclooxygenase, a key enzyme in the conversion of arachidonic acid to prostaglandins. Arachidonic acid is a polyunsaturated fatty acid found in daily food products (egg yolk, meat, and fish oil) and was suggested to have a key role in the development of Rheumatoid arthritis. Notably, however, the effect of dietary arachidonic acid to chronic disease, such as Rheumatoid arthritis is not well understood.
In this study, the authors determined the impact of dietary arachidonic acid intake on the inflammation status in rheumatoid arthritis. To this end, the team of researchers evaluated its effects when administered in different doses to an adjuvant-induced arthritis (AIA) rat model. The authors show that while dietary arachidonic acid intake increased, in a dose-dependent manner, no effect was observed in the expression of other lipid mediators or inflammatory cytokines in the rat arthritis model; additionally, no exacerbation of rheumatoid arthritis severity, measured by paw edema, arthritis score, and bone erosion was observed upon increased dietary arachidonic acid intake.