A dietary intervention centered on a vegan eating pattern significantly reduced disease activity and joint swelling among adults with rheumatoid arthritis, according to a study published in American Journal of Lifestyle Medicine.
The research was conducted by investigators from the Physicians Committee for Responsible Medicine and the George Washington University School of Medicine & Health Science. The study enrolled 44 adults previously diagnosed with rheumatoid arthritis and used a randomized, crossover design.
Participants were assigned to either a Diet phase or a Supplement phase for 16 weeks. During the Diet phase, participants followed a vegan diet for four weeks, eliminated additional foods for three weeks, and then gradually reintroduced those eliminated foods individually over nine weeks. During the Supplement phase, participants received a placebo. After a four-week washout period, participants switched to the opposite phase.
Researchers measured outcomes using the Disease Activity Score-28 (DAS28), a standard tool used to assess rheumatoid arthritis severity. During the Diet phase, the average DAS28 score dropped from 4.5 to 2.5, representing a statistically significant improvement. In contrast, during the Supplement phase, scores declined only slightly, from 3.2 to 2.9, a change that was not statistically significant.
The mean number of swollen joints also decreased during the Diet phase, falling from 7.0 to 3.3. During the Supplement phase, swollen joints slightly increased from 4.7 to 5.
In a subanalysis excluding individuals who increased medications during the study, DAS28 scores fell by 1.9 points during the Diet phase, compared to a 0.4-point decrease during the Supplement phase. Among participants who made no medication changes at all, disease activity still declined more during the Diet phase than during the Supplement phase.
Researchers concluded that the dietary intervention was associated with meaningful symptomatic improvements, suggesting that a vegan diet may play a role in managing rheumatoid arthritis severity.
