Although diet may play a vital role in mediating the symptoms of rheumatoid arthritis (RA), little is known about the influence of various diets on the disease. In a systemic review, published in Nutrients, study data demonstrate that dietary interventions with omega-3 supplementation provided additional benefits compared with diet only in an RA population.
Research showed that supplementation with omega-3 PUFAs resulted in significant improvements in the duration of early morning stiffness (EMS), pain levels, erythrocyte sedimentation rate (ESR), physical function, grip strength, joint tenderness, and levels of leukotriene B4 (LTB4), the investigators noted.
In a recent review, researchers evaluated the effects of different dietary interventions, with or without omega-3 supplementation, for the management of RA. The research included 20 studies with a total of 1063 participants. More than 80% of participants were women, mean age was 48.5 years, and they represented 9 countries –- Sweden, UK, Italy, Norway, Denmark, Finland, Netherlands, US, and Germany. Only 2 studies evaluated omega-3 PUFAs supplementation in combination with dietary intervention.
In 1 study, investigators reported significant reductions in C-reactive protein (CRP), tumor necrosis factor-α (TNF- α) and dose of corticosteroids in participants who followed both an anti-inflammatory diet and a Western diet with fish oil supplements. They found notable improvements in tender joints and LTB4 levels among the anti-inflammatory diet group only when omega-3 PUFAs was supplemented.
In a separate study, a diet rich in PUFAs (P:S ratio 5:0) in combination with omega-3 supplementation (1.6 g EPA/d and 1.1 g DHA/d) led to significant benefits in EMS, Ritchie’s index, and grip strength.
“This indicates that the anti-inflammatory benefits of a diet in combination with omega 3 PUFAs may be superior to the diet alone” the researchers explained.
The review also found that a vegetarian diet significantly improved several parameters of RA such as pain, physical function, grip strength, EMS, number of tender and swollen joints, as well as inflammation. The researchers noted that significant improvements in disease activity score, physical function, and overall health were found with a Mediterranean diet.
The review cites several study limitations such as the heterogeneity among the included studies, and the presence of various levels/qualities of evidence. In addition, the lack of standardization of outcome measures, variety of dietary interventions, comparators, and methodologies created difficulties with drawing conclusions. Finally, the majority of studies were considered to be unclear or have a high risk of bias, and they did not control for confounding variables.
“Dietary interventions with an anti-inflammatory basis may be an effective way for adults with RA seeking complementary treatments, potentially leading to improvements in certain parameters,” the review authors said. “However, there is a need for longer duration studies that are well-designed and sufficiently powered to investigate the influence of diet on RA.”
Disclosure: This research was supported by the School of Allied Health in the University of Limerick. Please see the original reference for a full list of disclosures.
Raad T, Griffin A, George ES, et al. Dietary Interventions with or without Omega-3 Supplementation for the Management of Rheumatoid Arthritis: A Systemic Review. Nutrients. Published online October 4, 2021. doi:10.3390/nu13103506