Sugary Soft Drinks Can Raise Risk of Rheumatoid Arthritis

A couple of sodas a day may increase a woman’s risk of developing rheumatoid arthritis (RA), according to a new study.

Published September 2014 in the American Journal of Clinical Nutrition, the study found that women who consumed one or more sugar-sweetened sodas a day had a 63% (HR: 1.63; 95% CI; 1.15, 2.3; P-trend = 0.004) higher risk of developing seropositive RA compared with women who consumed none or less than one serving a month.¹

The prospective study followed 79,570 women from the Nurses’ Health Study (NHS; 1980–2008) and 107,330 women from the NHS II (1991–2009). The association with sugary soda drinking was even stronger when limited to women with the onset of RA after age 55. No significant association was found with seronegative RA or diet soda intake, according to the report.

“Literature has consistently suggested a positive association between sugar-sweetened beverages and elevated risk of [type 2 diabetes and cardiovascular] diseases, so we are wondering if the similar association also exists for RA,” writes first author Yang Hu, a doctoral student in the department of nutrition at the Harvard School of Public Health at Harvard University in Boston, in an e-mail to The Rheumatologist.

“We are not very surprised about the main results because there are plausible biological mechanisms that might explain these findings,” adds Dr. Hu. “An interesting finding is that only sugar-sweetened soda, but not diet soda, was significantly associated with increased risk of RA. This might suggest the sugar is to blame for the observed association.”

Dr. Hu’s report was an observational study, and he’s looking forward to additional and larger cohort studies with extended follow-ups to explore potential biological mechanisms responsible for the results. He notes that without causality, it’s also too early to tell patients that diet sodas pose no risk of RA.

“I would not say [diet sodas are] ‘safe’ at this stage, because this is by far the first study reporting the [lack of] association between diet soda and RA risk,” he writes. “More studies are needed to confirm this finding.” (posted 11/21/14)

Richard Quinn is a freelance writer in New Jersey.

Reference

1. Hu Y, Costenbader KH, Gao X, et al. Sugar-sweetened soda consumption and risk of developing rheumatoid arthritis in women. Am J Clin Nutr. 2014 Sep;100(3):959–967.