Oily Fish Protects Against RA, but Smoking and Stress Increase Risk
Posted 6/17/08
New data presented at the Annual Congress of the European League Against Rheumatism show that intake of oily fish is associated with a reduced risk of developing rheumatoid arthritis (RA), whereas psychosocial work stress and smoking can increase the risk of developing the condition. The findings, all taken from a large population-based case-control study in Sweden called EIRA (Epidemiological Investigation of Rheumatoid Arthritis), shed light on the important role of environmental and social factors in the development of RA.
For the first time, the intake of oily fish has been demonstrated to have a protective effect against the development of RA, reducing an individual's risk by 20-30%. Interestingly, no significant association with RA risk was observed for consumption of fish oil supplements.
Tobacco smoking is an established risk factor for RA, but the investigators found that there is a dose dependency for the level of smoking (i.e. the number of cigarettes smoked across a given period) on the odds ratio of developing anti-citrulline (anti-CCP) positive RA. The highest odds ratios were seen in those carrying a risk variant of the susceptibility gene PTPN22.
Psychosocial stress at work, defined as low decision latitude (or low level of control) was found to be associated with a higher risk for RA.
Mrs. Annmarie Wesley of the Institute of Environmental Medicine, Stockholm, Sweden, EIRA investigator and lead author of the oily fish intake study, commented, "The findings from these studies add to an increasing body of evidence to support the assertion that lifestyle modifications can have a significant impact on an individual's risk for developing RA, one of the most common autoimmune diseases, affecting approximately 1% of adults worldwide. We hope that the data will contribute to the growing understanding of the aetiology of RA and, ultimately, its treatment and prevention."
This article was adapted from a press release issued by EULAR.
