Rheumatoid arthritis is an autoimmune condition characterised by chronic inflammation that results in extensive damage to synovial joints, leading to joint tenderness and swelling that can result in severe pain. Ordinarily, synovial joints are lined with a synovial membrane, a thin layer of tissue that produces fluid and helps to lubricate the joint. In rheumatoid arthritis, the immune system attacks this membrane and causes it to become inflamed and thickened, leading to painful and debilitating symptoms and can lead to permanent joint damage. In some cases, rheumatoid arthritis causes considerable disability. Rheumatoid arthritis affects about 456,000 Australians and 40,000 New Zealanders accounting for approximately 13% of all arthritic conditions.[2,3]
Rheumatoid arthritis is a chronic, inflammatory autoimmune condition. Although its cause is not completely understood, dietary intake can have a significant influence on levels of inflammation in the body and therefore increase the risk of developing rheumatoid arthritis and worsen symptoms for people who already have rheumatoid arthritis.
Western diets, especially those high in red and processed meat and dairy, increase inflammation. Meat and dairy contain arachidonic acid, which is converted to compounds in the body that are used to create prostaglandins, which are chemicals that produce the pain and swelling of inflammation.[3,4]
The nutrition prescription
Many studies have demonstrated that a WFPB diet reduces pain and improves function in rheumatoid arthritis.[4-7] A randomised controlled trial showed long-term improvements in the signs and symptoms of rheumatoid arthritis in 38 participants following a plant based diet comprising vegetables (including abundant root vegetables), fruits and nuts.  A further intervention using a whole food plant-based diet in 19 patients with osteoarthritis showed clinically significant improvements in pain and physical functioning. This supports earlier research showing a whole food plant-based diet improved symptoms such as the degree of pain, joint tenderness, and joint swelling in patients with rheumatoid arthritis. Plant-based dietary patterns are also associated with lower rates of inflammation in the body, demonstrated by lower levels of the inflammatory blood marker C-reactive protein.[7,10]
Gut health is also important in reducing inflammation, as a healthy intestinal barrier helps to stop toxins entering the bloodstream and creating inflammation. A diverse gut microbiome is essential in maintaining this barrier; a WFPB diet increases levels of many different types of good bacteria and is protective against inflammation.[11, 12]
WFPB diets are naturally lower in saturated fatty acids, a reduction in which has been shown to reduce inflammatory markers and increase the production of anti-inflammatory compounds such as short-chain fatty acids, further aiding in management of symptoms of rheumatoid arthritis.
In addition, maintenance of a healthy body weight, achieved on a WFPB diet, further reduces the risk of developing rheumatoid arthritis as well as managing the severity of symptoms in diagnosed cases.
Medical supervision of diet change is essential
Shifting to a low fat plant-based diet can lead to changes in medication requirements for glucose, blood pressure and lipid management as well as anti-inflammatory or immune suppressants; people who are on medications for rheumatoid arthritis should seek medical supervision.
There is little literature surrounding complete remission achievable with diet alone, however, a recent review concluded dietary management should both supplement and complement existing treatment strategies. In addition, dietary change to a plant based eating pattern is likely to result in large decreases in inflammatory cytokines and patient pain levels.
Diets high in fruits, vegetables and fibre are generally associated with lower BMI, markers of inflammation and risk of all autoimmune disorders. Risk of autoimmune disease such as hypothyroidism was found to be lower in all vegetarian and vegan participants of the Adventist Health Study cohort. Given the gut microbiome is involved in immune signalling, the high fibre and antioxidant content of plant based diets may provide some protection from inappropriate immune reactions. 
 The Royal Australian College of General Practitioners. RACGP – Rheumatoid arthritis. https://www.racgp.org.au/afp/2013/november/rheumatoid-arthritis/
 Australian Institute of Health and Welfare. Rheumatoid arthritis, What is rheumatoid arthritis? Australian Institute of Health and Welfare. https://www.aihw.gov.au/reports/chronic-musculoskeletal-conditions/rheumatoid-arthritis/contents/what-is-rheumatoid-arthritis
 Health Navigator New Zealand. Rheumatoid arthritis | Health Navigator NZ. Health Navigator New Zealand. https://www.healthnavigator.org.nz/health-a-z/r/rheumatoid-arthritis/
 Alwarith J, Kahleova H, Rembert E, et al. Nutrition Interventions in Rheumatoid Arthritis: The Potential Use of Plant-Based Diets. A Review. Front Nutr. 2019;6:141. doi:10.3389/fnut.2019.00141
 McDougall J, Bruce B, Spiller G, Westerdahl J, McDougall M. Effects of a very low-fat, vegan diet in subjects with rheumatoid arthritis. J Altern Complement Med N Y N. 2002;8(1):71-75. doi:10.1089/107555302753507195
 Khanna S, Jaiswal KS, Gupta B. Managing Rheumatoid Arthritis with Dietary Interventions. Front Nutr. 2017;4. doi:10.3389/fnut.2017.00052
 Sutliffe JT, Wilson LD, de Heer HD, Foster RL, Carnot MJ. C-reactive protein response to a vegan lifestyle intervention. Complement Ther Med. 2015;23(1):32-37. doi:10.1016/j.ctim.2014.11.001
 Hafström I, Ringertz B, Spångberg A, et al. A vegan diet free of gluten improves the signs and symptoms of rheumatoid arthritis: the effects on arthritis correlate with a reduction in antibodies to food antigens. Rheumatol Oxf Engl. 2001;40(10):1175-1179. doi:10.1093/rheumatology/40.10.1175
 Clinton CM, O’Brien S, Law J, Renier CM, Wendt MR. Whole-Foods, Plant-Based Diet Alleviates the Symptoms of Osteoarthritis. Arthritis. doi:https://doi.org/10.1155/2015/708152
 Haghighatdoost F, Bellissimo N, Totosy de Zepetnek JO, Rouhani MH. Association of vegetarian diet with inflammatory biomarkers: a systematic review and meta-analysis of observational studies. Public Health Nutr. 2017;20(15):2713-2721. doi:10.1017/S1368980017001768
 Menni C, Lin C, Cecelja M, et al. Gut microbial diversity is associated with lower arterial stiffness in women. Eur Heart J. 2018;39(25):2390-2397. doi:10.1093/eurheartj/ehy226
 Mielants H, Veys EM, Cuvelier C, De Vos M. Course of gut inflammation in spondylarthropathies and therapeutic consequences. Baillieres Clin Rheumatol. 1996;10(1):147-164. doi:10.1016/s0950-3579(96)80010-0
 Tonstad S, Butler T, Yan R, Fraser GE. Type of vegetarian diet, body weight, and prevalence of type 2 diabetes. Diabetes Care. 2009;32(5):791-796. doi:10.2337/dc08-1886
 Luca FD, Shoenfeld Y. The microbiome in autoimmune diseases. Clin Exp Immunol. 2019;195(1):74-85. doi:https://doi.org/10.1111/cei.13158