Nov. 11, 2010 (Atlanta) -- An extra jolt or two of caffeine may trigger a gout attack in people with the painful and often disabling arthritic condition, preliminary research suggests.
"We found that overall, as the number of servings of caffeinated beverages increased, so too did the chance of having recurrent gout attacks," says Tuhina Neogi, MD, PhD, associate professor of medicine at Boston University School of Medicine.
For example, drinking four servings of caffeinated beverages in the previous 24 hours was associated with an 80% increased risk of recurrent gout attacks, compared with having no caffeinated drinks.
Drinking more than six servings of caffeinated beverages in the previous day was associated with a 3.3-fold higher risk of a flare-up, the study of 663 gout patients suggests.
When habitual and occasional caffeine drinkers were looked at separately, the link was only observed in people with gout who typically drink less than two caffeinated beverages a day, Neogi tells WebMD.
"As little as three servings a day could do it for these people," she says.
"In contrast, in people with gout who usually have two or more caffeinated beverages a day, increasing caffeine intake doesn't appear to raise the risk of gout attacks," Neogi says.
The study does not prove cause and effect, just that there appears to be an association between higher caffeine intake in the past 24 hours and an increased risk of gout attacks. People with gout who drink a lot of revved-up beverages may share some other characteristic that makes them more prone to flare-ups, researchers say.
The findings were presented here at the American College of Rheumatology's annual meeting.
Caffeine's Chemical Structure Similar to Standard Gout Medication
Gout occurs when too much uric acid, a normal byproduct of DNA metabolism, builds up in the body. This leads to crystal formation. The crystals deposit in the joints, causing painful swelling.
Previous research has shown that, over the long term, caffeine intake is associated with lower levels of uric acid in the body and a lower risk of developing gout among people who do not have the arthritic condition, Neogi says.
The chemical structure of caffeine is very similar to that of a medication called allopurinol, which is commonly used to lower uric acid levels in people with gout, she says. Although effective at controlling gout in the long term, allopurinol can precipitate a flare-up among patients taking it for the first time, she says.
"Given the potential conflicting effects of caffeine on gout attack risk, we evaluated whether caffeinated beverage intake was associated with the risk for recurrent flare-ups," Neogi says.
Short-Term Caffeine Intake Linked to Gout
The researchers turned to the Internet to recruit 633 participants who had experienced a gout attack within the past year. Medical records were used to confirm their gout diagnosis.