This post discusses claims that caffeine can be used to treat asthma symptoms. It is part of our “AAFA Explains” series looking at complementary and alternative medicine (CAM) aimed at asthma and allergies. The Asthma and Allergy Foundation of America (AAFA) wants to guide you as you decide between choices that may be “likely safe” or “potentially unsafe.”

What is asthma?
Asthma is a chronic disease that causes your airways to become inflamed, making it hard to breathe. There is no cure for asthma. The best way to manage asthma is to avoid triggers, take prescribed medicine to prevent symptoms, and be prepared to treat asthma episodes if they occur.

Common symptoms of asthma are coughing, shortness of breath, wheezing and chest tightness. Asthma may lead to a medical emergency. It is important to know the signs of a severe asthma attack, and know how to treat it if it occurs.

What is caffeine?
Caffeine is an ingredient found in coffee, tea, cola drinks and cocoa and in over 60 plants. Drinks that contain caffeine are called “caffeinated” or “energy” drinks.

Caffeine stimulates the central nervous system. It can temporarily make you feel more awake, energetic and focused.

What does science tell us about caffeinated drinks and asthma?
Clinical studies have shown that caffeine is a weak bronchodilator, improving lung function for two to four hours after it is consumed. However, it is not as strong or fast acting as rescue bronchodilators like albuterol.

This would make it unsafe to use caffeine as an asthma treatment. This is because when consumed in very large doses, caffeine can cause unwanted side effects. These include insomnia, headaches, shakiness, upset stomach, bone thinning and more. In addition, in rare cases an overdose of caffeine can result in death due to convulsions or irregular heartbeat.

Is it safe to drink coffee and caffeinated drinks?
For most people it is safe to drink low to moderate amounts of coffee and other caffeinated drinks. However, at this point in time caffeine is not recommended as an asthma treatment.

Is it okay to consume caffeine before taking lung function tests?
No. Even small amounts of caffeine can affect the results of spirometry, a pulmonary (lung) function test, sometimes called PFTs. Spirometry is a common test that is done in the doctor’s office or in a lab. It is used to determine the severity of your asthma or the level of your asthma control.

Drinking coffee or other caffeinated drinks within four hours before performing spirometry can lead to incorrect test results. It might look like your lungs are working better than they really are. This can cause your doctor to prescribe a lower dose or a weaker drug than what you need to manage your asthma.

The bottom line:
You should avoid caffeine for at least four hours before any medical appointment that might include a lung function test.

Do not use coffee or other caffeinated drinks as a way to manage or treat asthma .

Key definitions:

• Randomized controlled trials: Participants are randomly placed into two groups. One group does not receive any treatment. The other group receives the treatment under consideration. Researchers follow both groups over time. At the end of the study, they compare results.
• Efficacy: Whether or not a treatment works, and by how much.

Reference:

Welsh E.J., Bara A., Barley E., Cates C.J. (2012 ). The effect of caffeine in people with asthma. Cochrane Database of Systematic Reviews

Medical Review October 2016.