Long-Term OA, RA Symptom Improvement Seen with Plant-Based Diet, Lifestyle Changes

Mechanisms Underpinning PFJ

Dr. Wagenaar and colleagues also sought to determine the possible mechanisms underlying the clinical effects of the plant-based diet on RA. “With RA, we have the mucosal origins hypothesis, which suggests RA is triggered at the mucosal site [of the gut] in genetically predisposed individuals, and this consequently transfers to the synovial [fluid in] joints,” she said.

“On top of this, we know that fiber protects our gut barrier and therefore reduces inflammation. The PFJ intervention is a very high-fiber program, so our hypothesis is that it might help [strengthen] the barrier,” she explained.

Dr. Wagenaar and colleagues collected fecal samples from patients and measured the albumin and calprotectin in them, which are both indicators of the gut barrier function. The researchers analyzed metabolomic data and found that fecal albumin — considered a gut barrier integrity marker — decreased significantly in the intervention group. In patients with RA, this improvement corresponded with an improvement in DAS28, the researchers reported in a poster at the meeting.

“Patients who had the greatest improvement in their gut barrier function also showed the greatest improvement in the DAS28 score, suggestive of a possible link between gut barrier improvement and clinical effects.”

They did not identify any change in calprotectin, an inflammation marker, but Dr. Wagenaar said this might change later. “We found that in those on the intervention, at 4 months, the CRP wasn’t reduced, but 1 year later it was.”

The metabolite lenticin, a lentil intake biomarker considered protective against inflammation and osteoclastic differentiation, also increased. Tryptophan was also reduced in people on the PFJ intervention.

Fernando Estevez-Lopez, PhD, a sports scientist at Harvard T.H. Chan School of Public Health, Boston, who specializes in physical activity and behavioral change in rheumatology patients, co-moderated the session and remarked that, “In this study, they did a brilliant job with encouraging participants to follow the program. The design and methods were really good — the sample size was good, and they followed people up. Also, these researchers come from Reade [a medical research center in Amsterdam University Medical Center] where they are well known for applying their research findings to the clinic,” he said.

“In terms of physical activity, we really mean increasing the time spent moving, for example, gentle activity such as walking, or changing behaviors in people with OA and RA. We don’t want them to have more pain the next day.”

Dr. Wagenaar reported receiving a grant from ZonMw (The Netherlands Organization for Health Research and Development). She and colleagues hold shares in Plants for Health, a limited liability company. Dr. Estevez-Lopez reported having no relevant disclosures.
 

A version of this article appeared on Medscape.com.