Milk and Beef Products Could Trigger Arthritis, Study Says

A risky bacteria is hidden in our milk, beef, and even some produce

Even milk that's been pasteurized is at risk.

You might not want to eat a burger after you read this — beef and milk products, such as cheese and yogurt, could increase your risk of arthritis, according to a new study from the University of Central Florida. Rheumatoid arthritis could be triggered in those who are genetically predisposed by bacteria often found in milk and beef products.

The bacteria Mycobacterium avium subspecies paratuberculosis, known as MAP, is found in approximately half of the cows in the United States. MAP can spread to humans after they consume milk or beef that’s been infected with the bacteria. Produce that’s been fertilized with the infected cows’ manure is also a risk.

Arthritis isn’t the only danger posed by this common bacteria found in American food. Saleh Naser, infectious disease specialist at UCF, had previously found a connection between MAP bacteria and Crohn’s disease. Naser noted that Crohn’s and rheumatoid arthritis are often treated using similar drugs and believed there could be a link.

“Here you have two inflammatory diseases, one affects the intestine and the other affects the joints,” Naser said in UCF’s report. “Do they have a common trigger? That was the question we raised and set out to investigate.”

The researchers found that 40 percent of the participants who were genetically predisposed for rheumatoid arthritis tested positive for MAP infection. This data suggested that there was a connection — arthritis could be triggered by the MAP bacteria in those genetically predisposed to the disease.

According to a study published in the Journal of Microbiology, Immunology and Infection, MAP is extremely difficult to spot from just looking at cattle. However, certain tests and detection methods exist for milk and beef products — though many are either inefficient or flawed.

Pasteurization of milk kills off low-level incidences of MAP but cannot completely kill off high concentrations of the bacteria.


Beef is also often infected with the MAP bacteria, though some is killed off during cooking. Bacteria or not, there are a few other things you might not know about supermarket beef.