Rheumatoid arthritis is a common autoimmune disease that causes joint pain, swelling, and eventually permanent joint damage. It occurs when the immune system mistakes healthy body tissues as threats and strives to remove them from the body. Unlike the wear-and-tear of osteoarthritis, rheumatoid arthritis attacks the lining of the joints resulting in painful swelling that eventually erodes the bones and deforms joints. This inflammation can also cause damage to other parts of the body such as the skin, eyes, lungs, heart and blood vessels which can result in severe physical disabilities. (1)
In a study published in April 2022 by the Physicians Committee for Responsible Medicine (PCRM), a plant-based vegan diet without calorie restriction significantly improved joint pain in patients with rheumatoid arthritis. The participants were 44 adults diagnosed with rheumatoid arthritis. At the beginning of the study, they were asked to identify the severity of their joint pain over the past two weeks, from “no pain” to “pain as bad as it could possibly be”, using the visual analog scale (VAS). In addition, the Disease Activity Score 28 (DAS28) of each participant was calculated. DAS28 scores indicate inflammation in the body and increase with the severity of the rheumatoid arthritis. (2)
Note: VAS ratings offer a simple, valid and effective method to measure pain intensity and pain progression as well as a comparison of pain severity between patients with similar conditions and can be used to assess disease control. (3) DAS28 (Disease Activity Score 28) indicates the severity of rheumatoid arthritis disease activity at a given moment in time. It is calculated based on several different factors, including lab results such as C-reactive protein values (an indication of inflammation); joint swelling and tenderness of 28 joints, and patient feedback. (4)
Participants were randomly divided into two groups. The first group followed a self-prepared, research team-guided plant-based vegan diet for four weeks followed by the elimination of additional foods for three weeks and then the reintroduction of the eliminated foods individually over the next nine weeks. The second group followed an unrestricted diet which included a placebo supplement capsule for sixteen weeks. After this, the groups switched diets for the next sixteen weeks. (2)
Results illustrated the following (2);
During the vegan phase, DAS28 decreased 2 points on average (from 4.5 to 2.5) while the DAS28 of those on the placebo phase decreased 0.3 points (from 3.2 to 2.9). Decreasing DAS28 indicates less joint pain.
The average number of swollen joints decreased from 7.0 to 3.3 in the vegan phase while the average number of swollen joins increased from 4.7 to 5 in the placebo phase.
VAS ratings also improved significantly during the vegan phase compared to the placebo phase.
The vegan diet was additionally linked to greater decreases in DAS28 in two sub-analyses, one that excluded patients who increased their medication intake during the study as well as one limited to only participants who made no medication changes during the study. Furthermore, the vegan phase was associated with other health benefits such as weight loss of an average of 14 pounds (compared to a 2-pound weight gain during the placebo phase) and decreased total, LDL and HDL cholesterol.
The study researchers concluded that a plant-based vegan diet could be a safe route for relieving the joint pain of those suffering from rheumatoid arthritis with the additional advantage of side effects that are only beneficial.
2 Barnard, N.D., Levin, S., Crosby, R.D., Flores, R., Holubkov, R., Kahleova, H. A Randomized, Crossover Trial of a Nutritional Intervention for Rheumatoid Arthritis. American Journal of Lifestyle Medicine. April 3, 2022. Doi.org/10.1177/15598276221081819.