“A plant-based diet could be the prescription to alleviate joint pain for millions of people suffering from rheumatoid arthritis,” says Neal Barnard, MD, lead author of the study and president of the Physicians Committee. “And all of the side effects, including weight loss and lower cholesterol, are only beneficial.” Rheumatoid arthritis is a common autoimmune disease that typically causes joint pain, swelling, and eventually permanent joint damage.
At the outset of the Physicians Committee’s study, participants were asked to use a visual analog scale (VAS) to rate the severity of their worst joint pain in the preceding two weeks, from “no pain” to “pain as bad as it could possibly be.” Each participant’s Disease Activity Score-28 (DAS28) was also calculated based on tender joints, swollen joints, and C-reactive protein values, which indicate inflammation in the body. DAS28 increases with rheumatoid arthritis severity.
During the study, 44 adults previously diagnosed with rheumatoid arthritis were assigned to one of two groups for 16 weeks. The first group followed a vegan diet for four weeks, with the elimination of additional foods for three weeks, then reintroduction of the eliminated foods individually over nine weeks. No meals were provided, and participants handled their own food preparation and purchases, with guidance from the research team. The second group followed an unrestricted diet but were asked to take a daily placebo capsule, which had no effect in the study. Then the groups switched diets for 16 weeks.