Get the Red Out

In results published in the December 2004 issue of Arthritis & Rheumatism University of Manchester researchers Dorothy J. Pattison, Deborah Symmons, Alan Silman, et. al. found an increased risk of rheumatoid arthritis in people who consume a lot of red meat, and an increased risk of inflammatory arthritis in high protein consumption in general.

The researchers first looked at 25,000 people enrolled in the "European Prospective Investigation of Cancer," a large, established (decade-old) research study of Europeans between the ages of 45 and 70. Within this population, they identified 88 new patients with inflammatory arthritis, affecting at least two major joints, and asked them to keep a detailed week-long food diary for their study of RA. The patients were then matched, for age, sex, and body mass index, with 176 controls. Analysis of their habits showed that although these participants were more likely to have been former smokers and consumed fewer foods that contained vitamin C, the researchers found that their consumption of red meat put them at twice the risk of developing rheumatoid arthritis over those who ate the least amount of red meat.

Interestingly, people who ate the most protein overall (more than 75g daily), including other forms of meat and plant protein, ran triple the risk of inflammatory disease over those who ate the least (less than 62g daily). Additionally, eating fat did not seem to raise the risk, the researchers found.

Silman and Symmons were unsure as to why RA was more likely to strike these carnivores. "It may be that the high collagen content of meat leads to collagen sensitisation and consequent production of anticollagen antibodies," they wrote. "Meat consumption may be linked to either additives or even infectious agents, but, again, there is no evidence as to what might be important in relation to rheumatoid arthritis."

Red meat consumption may also merely be a "lifestyle marker" for people who are at a greater risk of developing rheumatoid arthritis. "It is unclear whether the association is a causative one," the researchers wrote.

For example, previous studies have shown that diets lacking in fruit and lacking in vitamin C have led to an increased risk of RA. It may be the case that red meat eaters eat meat in place of fruits and vegetables. Until then, it might behoove you to make sure your current diet provides you with all the nutrients you need.

Article References
Compiled from CBS News and Reuters reports.