Coffee is one of the most consumed beverages worldwide. In the United States, the average daily consumption is approximately three cups, and nine out of ten adults opt for a cup at breakfast.
Around 25 million people in the United States, or approximately 1 in every 13 Americans, have asthma (this number represents about 8 percent of adults and 7 percent of children who are affected). According to statistics, women appear to have a higher prevalence of asthma than men. 2Caffeine has been shown in studies to have a similar effect to a weak bronchodilator (a type of medication that helps with breathing), temporarily relieving and improving lung function for up to two to four hours after consumption. Coffee, on the other hand, will not provide the immediate relief or strong effect that bronchodilators such as albuterol do.
Asthma and coffee
A study in Korea examined the relationship between coffee and asthma (green tea and soda were also included) based on growing evidence that sugary drinks like soda during pregnancy, childhood, and adulthood may lead to asthma development; researchers hypothesized that coffee (and green tea) may act as a bronchodilator and help in alleviating allergic inflammation.
The researchers analysed the frequency of beverage consumption by participants (3,146 with asthma and 158,902 without a history of asthma), as well as the amount consumed.
Their findings indicated that coffee consumption decreased the prevalence of asthma and, surprisingly, had a greater beneficial effect on the female subgroup than on the male subgroup.
Additionally, researchers discovered that the link between asthma and coffee is due to the methylxanthines (weak bronchodilators) found in coffee. The researchers concluded that drinking one cup of coffee, one to two times per day, may have anti-asthmatic properties.