According to a new study published in the American Journal of Lifestyle Medicine, an entirely plant-based diet may key to reducing the pain and symptoms of rheumatoid arthritis – an autoimmune condition that typically triggers inflammation, pain, swelling, and stiffness across the joints, and eventually, permanent joint damage.

Meat , dairy, and rheumatoid arthritis

A total of 44 participants, who were previously diagnosed with rheumatoid arthritis, underwent the study to investigate the health effects of eliminating meat and dairy. 

Researchers found a significant improvement in the severity of symptoms after following a low-fat vegan diet free, from calorie restriction. Participants also experienced weight loss and improved serum cholesterol levels.  

The study

At the start of the study, participants used a visual analogue scale to classify the severity of their joint pain, from “no pain” to “pain as bad as it could possibly be.”

Joint pain was also assessed using the Disease Activity Score-28 (DAS28), a pain indicator tool that measures inflammation activity in rheumatoid arthritis using clinical data. The participants were then divided into two groups for 16 weeks.

Group 1 vs group 2

One of the groups were instructed to follow a vegan diet for four weeks, followed by removing potential pain-trigger food items for three weeks. They were then re-introduced to the removed food items for the duration of the study. 

The second group followed an unrestricted diet, where they were able to eat whatever they wanted to for 16 weeks. They were also given a placebo capsule, which had no effect on the study. At the end of the 16 weeks, the two groups went on to switch diets.  

Results

The researchers noticed a significant difference in DAS28 scores between the two groups at the end of the study. They found that during the vegan diet phase of the study, DAS28 scores dropped by two points on average, indicating a greater reduction in joint pain, compared to a decrease of 0.3 points in the placebo phase. 

The average number of swollen joints also went down from 7.0 to 3.3 in the vegan phase. However, the number actually increased from 4.7 to 5 in the placebo phase. The researchers also noted that VAS ratings improved significantly in the vegan phase, compared with the placebo phase.

Additional health benefits

As well as the reduction in pain and swelling of the joints, the study also found that the vegan phase led to additional health benefits, including decreased LDL and HDL cholesterol levels.

Researchers also found that body weight decreased by about 14 pounds on average when eating plant-based, compared to a gain of about two pounds on the placebo diet. 

The research was conducted by the Physicians Committee for Responsible Medicine (PCRM), a non-profit organization that focuses on preventative medicine and higher ethics standards in education and research.