Should beef and dairy products be avoided by people with rheumatoid arthritis? Maybe, says a new study. Share on Pinterest We all heard it growing up: Milk does a body good. But milk — along with beef products — may not be good for people living with the painful and sometimes disabling autoimmune condition, rheumatoid arthritis. In a new study, researchers concluded that a strain of bacteria typically found in milk and beef may be linked to rheumatoid arthritis (RA). While it’s been known that some patients’ RA symptoms may respond to adding or eliminating certain foods to their diet, this study is the first to specifically link bacteria found in beef and dairy to the ailment. Researchers out of the University of Central Florida found that the bacteria strain mycobacterium avium subspecies paratuberculosis, also called MAP, can trigger RA in already susceptible individuals. So while MAP may not necessarily cause RA in everyone, it can influence the development of the disease in people who are genetically predisposed to the condition. This study piggybacks off previous research done by the same team of researchers that looked at the association of MAP and Crohn’s disease.

What the study revealed The latest study was conducted by infectious disease specialist Saleh Naser and rheumatologist Shazia Bég. It was inspired by Naser’s previous study linking this bacteria and gastrointestinal diseases. “Here you have two inflammatory diseases, one affects the intestine and the other affects the joints, and both share the same genetic defect and [are] treated with the same drugs,” Naser said in a press statement. “Do they have a common trigger? That was the question we raised and set out to investigate.” So they set out to determine if MAP was that shared trigger. Bég recruited 100 of her rheumatology patients for this study. These subjects gave clinical samples for scientific testing. It was found that 78 percent of the patients with RA had a mutation in their PTPN2/22 gene — the same genetic mutation that’s found in people with Crohn’s. In addition, 40 percent of that number also tested positive for the MAP found in beef and cow’s milk. Because of this, the researchers believe that people born with this genetic mutation who also ingest MAP are prone to develop RA or Crohn’s. Not all cattle are infected with MAP and other dairy products besides beef and milk weren’t looked at in the study. “We don’t know the cause of rheumatoid arthritis, so we’re excited that we have found this association,” Bég said in a statement to the press about the study, which was published in the medical journal, Frontiers in Cellular and Infection Microbiology. “But there is still a long way to go. We need to find out why MAP is more predominant in these patients — whether it’s present because they have RA, or whether it caused RA in these patients. If we find that out, then we can target treatment toward the MAP bacteria.” This isn’t the first time that food and RA have been linked. Another recent study showed that eating a bowl of muesli for breakfast each day could minimize your symptoms.