A recent meta-analysis1 calculates that about one third of rheumatoid arthritis cases in the US could be avoided by changing three lifestyle factors: smoking, overweight and alcohol consumption. Especially smoking and overweight increase the risk of arthritis. Alcohol consumption on the other hand, is associated with a lower risk. Eight percent of the cases of arthritis that could be avoided are associated with abstention or low alcohol consumption.
What is already known? Previous meta-analyses2,3 found that alcohol consumption is associated with a decreased risk of rheumatoid arthritis, suggesting a protective effect of alcohol.
What does this study add? The study does not only look at the effect of alcohol consumption, but at multiple lifestyle factors.
Lower risk with alcohol consumption
The authors dove into the scientific literature to find lifestyle factors for which there is high scientific evidence that they influence the risk of rheumatoid arthritis. One of these factors is alcohol consumption. In the current meta-analysis, they indeed find that each additional five alcohol consumptions per week (50 grams alcohol) is associated with an 8% lower risk.
The underlying mechanism of this association is not studied, but the authors suggest it may be that alcohol downregulates the immune response and decrease the production of proinflammatory cytokines: two important causes of arthritis (see below).
Proportion of avoidable cases
Apart from alcohol consumption, two other lifestyle factors came out of the literature search: smoking and overweight/obesity. The authors wanted to know how many rheumatoid arthritis cases in the US could be avoided by modifying or removing the exposure to these lifestyle factors.
Results show that these three lifestyle factors account for almost 33% of rheumatoid arthritis cases that could be avoided. Overweight is the biggest culprit with almost 15%, followed by smoking with 14%. Not drinking alcohol, or only low alcohol consumption, accounts for 8% of the cases.
However, “the decision of whether alcohol drinking is beneficial becomes a trade-off, because it might increase the proportion of heavy drinkers and thereby enhance the risk of other diseases such as stroke, some cancers, cirrhosis of the liver or injuries”, warn the authors.1
Rheumatoid arthritis
Rheumatoid arthritis is an autoimmune disorder in which the immune system attacks healthy joint tissues and causes inflammation. It typically results in warm, swollen, and painful joints. It can make you to feel tired, have occasional fevers, and have a loss of appetite. It may also cause other medical problems in the heart, lungs, blood, nerves, eyes, and skin.4
Strengths
- Only longitudinal studies
- Quality of studies assessed
- Multiple lifestyle factors included
Shortcomings
- Observational study: cannot prove causality
- Only US participants
- Not all risk factors taken into account (e.g. diet)
References
- Ye, D., Mao, Y., Xu, Y., Xu, X., Xie, Z., & Wen, C. (2021). Lifestyle factors associated with incidence of rheumatoid arthritis in US adults: analysis of National Health and Nutrition Examination Survey database and meta-analysis. BMJ open, 11(1), e038137.
2. Scott, I. C., Tan, R., Stahl, D., Steer, S., Lewis, C. M., & Cope, A. P. (2013). The protective effect of alcohol on developing rheumatoid arthritis: a systematic review and meta-analysis. Rheumatology, 52(5), 856-867. - Jin, Z., Xiang, C., Cai, Q., Wei, X., & He, J. (2014). Alcohol consumption as a preventive factor for developing rheumatoid arthritis: a dose-response meta-analysis of prospective studies. Annals of the rheumatic diseases, 73(11), 1962-1967.
- National Institute of Arthritis and Musculoskeletal and Skin Diseases. Rheumatoid Arthritis. Accessed at 15 February 2021.