2022 American College of Rheumatology (ACR) Guideline for Exercise, Rehabilitation, Diet, and Additional Integrative Interventions for Rheumatoid Arthritis

Nutrition has received considerable attention as a therapeutic approach for the treatment and management of rheumatoid arthritis (RA). In this issue of Arthritis Care & Research, the importance of nutrition in disease management is highlighted by England et al, in the 2022 American College of Rheumatology (ACR) Guideline for Exercise, Rehabilitation, Diet, and Additional Integrative Interventions for Rheumatoid Arthritis (1). The intent of this editorial is to recognize the nutritional recommendations reported in the guideline, and to present strategies for health care providers to incorporate nutrition as part of the care plan for patients with RA. While several nutrition interventions have been studied, a Mediterranean-style diet (MD) is the only formal diet conditionally recommended according to the guideline. Other formal diets may offer symptomatic benefits for patients; however the voting panel did not find sufficient evidence to provide a recommendation for such diets. Dietary supplements are also considered in the recommendations. The guideline emphasizes a “food first” approach without additional dietary supplements, although authors acknowledge supplements may be helpful in certain cases. The conditional recommendation for an MD stems from the evidence supporting this type of diet for RA management and reducing the risk of associated comorbidities. Improved physical function, reduced joint swelling, and lessened pain are some benefits described in the MD studies. The primary foods in an MD pattern are olive oil, legumes, whole grains, fruits, vegetables, fish, and a serving of red wine, with moderate dairy, mainly consumed as yogurt and cheese. Red meat, highly processed foods, and sweets are limited in this diet. The MD is considered to have antiinflammatory effects, due to the intake of monounsaturated fats and polyphenols in olive oil, the antioxidants in fruits, vegetables, and red wine, and the omega-3 fatty acids in fish (2). These nutrients have the potential to modulate inflammatory pathways and reduce biomarkers of inflammation. Another relevant aspect of this diet is that it is high in fiber from legumes, whole grains, fruits, and vegetables. Fiber plays an important role in supporting a diverse and healthy microbiome, and alterations in the microbiome are seen among patients with RA (3). A recent study of a cohort of individuals with RA found that higher adherence to an MD resulted in a healthier microbiome profile (4). Aside from the benefits seen in RA, the MD is often described as an ideal eating pattern for cardiovascular disease prevention, which is a significant comorbidity experienced by patients with RA (5). Long-term patient compliance to a diet is important to achieve desired outcomes. Adherence to an MD may be best achieved if the diet pattern is adapted to diverse cultures. The guideline therefore states specifically “a Mediterranean-style diet,” recommending that individual cultural preferences to food and cooking practices are incorporated, while preserving the health-promoting elements of the MD. Food alternatives for the MD as appropriate for other cultures may include substituting or supplementing olive oil with other monounsaturated fats (such as expeller pressed canola oil), including local fish, whole grains, native fruits and vegetables, herbs, and spices. A helpful resource for clinicians and patients on traditional diets that share characteristics of an MD is https://oldwayspt.org/. This site provides information on cultural food patterns with similar nutritional profiles as the MD. Patients interested in following an MD should also consult with a registered dietitian nutritionist (RDN). RDNs are skilled professionals trained to support sustainable dietary changes, with cultural competence in mind. The recent guideline does not recommend other formally defined diets, due to the low certainty of evidence. Despite uncertainty in the research, individual attempts at other therapeutic diets may be of interest to some patients. Tailored vegan and elimination diets often exclude food antigens that trigger immune responses, with the goal of reducing markers of inflammation, joint tenderness, and pain (6). Fasting and diets that mimic fasting have been shown to have antiinflammatory effects (7). These diets have the potential to improve disease activity, however they are restrictive and complex for patients to follow and may increase the risk of nutrient deficiencies. Patients who wish to try these therapeutic diets to manage RA should consult with RDNs and medical providers to ensure safety and prevention of micronutrient deficiencies. Despite growing support for nutrition as a therapeutic component in the management of RA, there are still gaps and challenges in implementing nutritional care. Conflicting outcomes and a range in the quality of evidence among research studies may be one barrier for clinicians to recommend a nutritional approach for patients. More research is needed to strengthen recommendations; however, it is important to acknowledge some known challenges of nutrition studies that are hard to overcome. The gold standard for research is the randomized, double-blind controlled trial. Whole food dietary pattern studies are complex and it is difficult to blind participants to whole foods or nutrients in the study diets. Studies on dietary supplements also have limitations. A major challenge is that the form and dose of a nutrient consumed as a supplement can impact bioavailability and, in turn, effectiveness. Fish oil supplements are recognized by the guideline as potentially beneficial for preventing cardiovascular disease. There is contradicting literature on the effectiveness of omega-3 fatty acids on RA due to the different forms of these fatty acids available for research and consumer use (e.g., re-esterified triglyceride versus ethyl ester forms), varying doses and durations of the studies, and the effects of confounding factors such as baseline dietary intake. Nonetheless, it is critical to continue studying the impact of nutritional therapies on RA, in order to better understand the effects of nutrients on inflammation, microbiota composition, and comorbidities. Research studies on multicultural diets similar in nutrient density to the MD are also needed. Another barrier to including nutritional strategies might be limited access to RDNs. RDNs are essential partners in delivering high quality nutrition care and effectively guiding patients through nutritional interventions. Including RDNs in multidisciplinary RA treatment teams would provide practitioners with unique skills that help patients adhere to nutritional guidelines, improving health and reducing the risk of comorbidities. The American College of Rheumatology recognizes RDNs as part of the team of providers designated to care for patients with rheumatic disease (8). If RDNs are not part of a rheumatology practice, patients can be referred through the online referral database that locates an RDN in their area. Patients and practitioners can access this database at: https://www.eatright.org/find-a-nutrition-expert. This database is maintained by the Academy of Nutrition and Dietetics. In conclusion, the new guideline is a significant step in recognizing the importance of nutrition and other nonpharmacologic interventions for RA. An integrative approach supported by an interdisciplinary team of providers may be optimal for improving clinical symptoms and reducing risk of associated chronic conditions in patients with RA. Dr. Everett drafted the article, revised it critically for important intellectual content, and approved the final version to be published. Disclosure Form Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.