The research builds on previous studies suggesting that caffeine may be associated with decreased asthma symptoms. In the current study, researchers studied 10 asthmatic patients. Sixty minutes before exercising on a treadmill, participants were given doses of caffeine of 3, 6, or 9 mg/kg of body weight, or Placebo for the control group. The study was what is known as a double−blind, "double−dummy" paradigm (this last term simply implies that all participants eventually received all doses and the placebo at different points in the experiment). Researchers tested pulmonary function 15 minutes before, and 1, 5, 10, 15, and 30 minutes after the exercise challenge.
[T]aking 9 mg/kg of caffeine ... was just found to be just as effective at reducing EIA symptoms as using an albuterol inhaler.
When participants ingested 3 or 6 mg/kg of caffeine, they showed significantly less wheezing and coughing during the challenge than when they took placebo. Even more interesting was the result of taking 9 mg/kg of caffeine, which was just found to be just as effective at reducing EIA symptoms as using an albuterol inhaler. There seemed to be no added bonus to using an inhaler along with ingesting caffeine.
The researchers have also looked at other possible alternatives to albuterol in reducing the symptoms of EIA — some of which include fish oil, various antioxidants, and reduction of salt intake. They point out that using any medication repeatedly may reduce its efficacy in the long run. There are also the some health concerns and side effects associated with using an inhaled corticosteroid (such as albuterol) for a prolonged period, which might be avoided if effective alternatives can be determined.
This study, led by researcher Timothy A. VanHaitsma, was presented at the American College of Sports Medicine in May 2009.