Red meat consumption raises risk of inflammatory arthritis?

High level red meat consumption could be a novel risk factor in developing inflammatory arthritis, say UK researchers, or it may act as a marker for people with an increased risk from other lifestyle causes, reports Lindsey Partos.

After adjusting for smoking and other possible dietary factors, participants with the highest level of red meat consumption in the trial of 25,000 men and women had a two-fold risk of rheumatoid arthritis.

"It may be that the high collagen content of meat leads to collagen sensitisation and consequent production of anticollagen antibodies, most likely in a subgroup of susceptible individuals," said the study authors led by Professors Alan Silman and Deborah Symmons at the University of Manchester.

Routinely eating burgers and steak, however, may only influence people with a predisposition for RA as the reasons behind the influence remain unclear.

The British team suggest 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 RA'.

"It is unclear whether the association is a causative one," said Dr Pattison, one of the study authors.

Red meat consumption (beef, pork and lamb) in the UK has rebounded to pre-BSE levels with consumers eating 43.2 kilos per year, per head, or a total of 2.6 million tonnes. In 1996, at the height of the BSE crisis, consumption dipped to 2.3 million tonnes.

Inflammatory arthritis is a common early sign of rheumatoid arthritis (RA), a chronic inflammatory disease of the immune system, linked to a combination of genetic and environmental factors.

More than 7 million adults in the UK - 15 per cent of the population - have long-term health problems due to arthritis and related conditions, according to the Arthritis Research Campaign. Across Europe the number of arthritis sufferers is slated to escalate as the population ages and other major risk factors, such as obesity, also increase.

The role of nutritional factors in the health condition is less certain but studies have suggested the protective benefits of eating fish, the dangers of drinking coffee, and a reduction in disease risk for women who enjoy alcohol in moderation. Such associations, are still wide open to debate and further research.

Building on recent findings that a diet lacking in fruit, especially varieties high in vitamin C, increases the risk of inflammatory arthritis, as much as three-fold the UK researchers set out to investigate the association of other dietary habits with the onset of RA.

The team tracked over 25,000 men and women between the ages of 45 and 75 enrolled in the European Prospective Investigation of Cancer in Norfolk, UK.

Within this population, 88 new patients with inflammatory arthritis, affecting at least two major joints, were identified. The patients were then matched, for age, sex, and body mass index, with 176 controls.

"The most striking difference between the two groups was directly related to red meat consumption," report the researchers in the December 2004 issue of Arthritis & Rheumatism.

High levels of dietary fats, including saturated fat, did not appear to have an impact on the risk, in contrast the team found that a higher level of protein intake in general was associated with an increased disease risk.