April 25, 2022 – The aches and pains caused by rheumatoid arthritis appear to be connected to what we eat, but researchers haven’t been able to develop an ideal diet for patients.
Now, a new study in women suggests that adopting a low-fat vegan diet and then getting rid of trigger foods may bring relief within months, possibly by helping patients to quickly shed weight.
The unusual design of the study and its tiny size make it impossible to know if the diet – or some part of it – actually works. Still, the diet is “a life-changing experience for people,” says lead author Neal D. Barnard, MD, an internal medicine specialist and president of the Physicians Committee for Responsible Medicine. “Doctors should know about it, and they should try it themselves.”
The study was published April 3 in the American Journal of Lifestyle Management.
About 1 in 200 people (or more than 1.6 million people) in the U.S. have rheumatoid arthritis, which is caused when the immune system goes haywire and attacks the body’s joints. It’s more common in women and causes symptoms such as swelling, stiffness, and pain.
Doctors have linked rheumatoid arthritis to diet for decades, and a 2017 survey of 217 patients with the condition found that 19% said certain foods, such as sugary soda and sweets, made their symptoms worse. But there’s no consensus on the best diet for relief.
A 2021 review of research found positive results for the Mediterranean diet, high doses of omega-3 fatty acids (which are found in fish oil), vitamin D supplements, and cutting out salt. Other approaches, such as fasting and vegan diets, have had inconclusive results.
For the new study, researchers wanted to explore the possible benefit of a “practical and easy-to-prescribe diet” without limits on calories, Barnard says.
Researchers randomly assigned 44 women (average age of 57, 66% white and 16% Black) to one of two diets for 16 weeks. The women then took a break for 4 weeks and were on the other diet for 16 weeks. This “crossover” approach means that all 32 people who completed the study were exposed to each diet.
One diet was low-fat and vegan. After 4 weeks, those on the diet didn’t use common rheumatoid arthritis trigger foods such as grains with gluten, nuts, citrus, and chocolate. After week 7, the women added back the trigger foods one-by-one, keeping them in their diet if they didn’t seem to cause symptoms.
People on the other diet took a placebo.
After participants were on the low-fat vegan diet for 16 weeks, their average number of swollen joints dipped from 7 to just more than 3, and they reported better overall symptoms.
Average body weight fell by a whopping 14 pounds among those in the diet group, while those in the placebo group gained an average of almost 2 pounds.
It’s not clear if the lost weight is more responsible for the diet’s benefits than the actual foods, says Harvard Medical School rheumatologist Daniel Solomon, MD, who reviewed the study findings for WebMD. Another possibility is that certain parts of the diet – and not the full diet – were responsible, he says.
“I am sure that motivated patients could follow such a diet,” he says, “but first we should determine if the specific diet was the key issue or whether weight loss was more important.”
Barnard, the study’s lead author, says patients tolerated the diet well. “It’s practical for day-to-day life” and cheaper than diets with meat and dairy, he says.
He encourages patients to try changing their eating patterns before turning to medication.
“It’s a good idea for anyone to have a chance to try a diet change,” he says. “You’ll know within a matter of weeks whether it will work.”