People who eat lots of red meat may be raising their risk of rheumatoid arthritis, an incurable and crippling disease, British researchers reported on Thursday. A study of 25,000 people living in Europe shows that those who ate the most red meat had double the risk of rheumatoid arthritis, compared to those who ate the least amount. And people who ate more protein overall, including other forms of meat and plant protein, also had a higher risk of the disease while eating fat did not seem to raise the risk, the researchers found. Rheumatoid arthritis is an autoimmune disease in which the body's immune cells mistakenly attack healthy joints. Maybe eating meat somehow sets the body up to attack similar components, the researchers wrote in the latest issue of the journal Arthritis & Rheumatism. "It may be that the high collagen content of meat leads to collagen sensitization and consequent production of anticollagen antibodies," Alan Silman and Deborah Symmons at the University of Manchester wrote in their report. --More 2209 Local Time 1909 GMT