Food for Thought: On Eating & Inflammation in Rheumatic Disease

Would an FMD/refeeding regimen work in humans? The researchers randomly assigned 60 patients with relapsing-remitting MS to follow either a normal or ketogenic diet for six months, or a modified human FMD for seven days followed by a Mediterranean diet for six months. Health-related quality of life scores in the FMD group were 50% higher than those on the ketogenic diet. Patients were highly compliant with all three diets.

In a recent trial, the researchers injected mice with dextran sodium sulfate (DSS) to trigger inflammatory bowel disease. They found the mice had increased levels of inflammatory CD4+ and CD8+ T cell infiltrates in the villi of their small intestine, as well as shortened colons. The mice were fed short cycles of the FMD followed by refeeding.³

Their intestinal T cell levels reverted to near normal and their colons were also restored to normal lengths, a possible sign that the diet can promote tissue regeneration, said Dr. Longo. Fecal tests also showed the mice had higher levels of protective gut bacteria after the diet trial (including Lactobacillaceae, Erysipelotrichaceae and Bifidobacteriaceae), possibly due to eating so many vegetables. “We think the prebiotic-rich ingredients give fuel to the bacteria, which grow and take over the gut, and they may contribute to the regeneration of stem cells and an anti-inflammatory effect.”

Diet, RA & SLE
Certain nutrients or dietary patterns may affect inflammation and rheumatic disease risk in certain populations, said Sara Tedeschi, MD, MPH, a rheumatologist at Brigham and Women’s Hospital and assistant professor of medicine at Harvard Medical School, Boston.

“Patients with rheumatic diseases often ask their rheumatologists what they should eat and, specifically, whether they should eat more of or avoid certain foods to improve their disease,” she said. Recommended nutrients include omega-3 fatty acids found in fish, poultry or nuts. They may decrease production of inflammatory eicosanoids and cytokines, and downregulate NLRP3 in the inflammasome. Dietary fiber may have an anti-inflammatory effect. “When fiber is ingested in the diet, it’s cleaved to short-chain fatty acids by the intestinal microbiome, and it’s thought that short-chain fatty acids then exert anti-inflammatory effects on macrophages, dendritic cells and regulatory T cells.”⁴

Recent evidence suggests omega-3s in the diet may lower rheumatoid arthritis (RA) risk in people at higher genetic susceptibility. Higher omega-3 levels in erythrocyte membranes were associated with lower risk of developing anti-cyclic citrullinated peptide (CCP) and rheumatoid factor positivity, as well as incident seropositive RA.⁵ A meta-analysis of seven studies on fish consumption and risk of incident RA indicated a non-significant inverse relationship between each additional serving of fish eaten per week and risk of RA.⁶