What affect does caffeine do on the lungs?

Bronchodilation

Caffeine has been shown to have a bronchodilatory effect, meaning that it can relax the muscles of the airways and improve airflow. This effect is thought to be mediated by the adenosine receptor-blocking properties of caffeine. Adenosine is a neuromodulator that can cause bronchoconstriction, so blocking its effects can lead to relaxation of the airways.

Increased respiratory rate

Caffeine can also increase the respiratory rate, which can help to improve oxygenation and clear mucus from the lungs. This effect is thought to be due to the stimulant properties of caffeine, which can increase the activity of the central nervous system.

Improved lung function

Caffeine has been shown to improve lung function in people with asthma and other respiratory conditions. In one study, for example, caffeine was found to improve forced expiratory volume in one second (FEV1) and forced vital capacity (FVC) in people with asthma. Another study found that caffeine improved lung function in people with chronic obstructive pulmonary disease (COPD).

Reduced risk of respiratory disease

Some studies have also suggested that caffeine may help to reduce the risk of developing respiratory diseases such as asthma and COPD. This is thought to be due to the anti-inflammatory effects of caffeine. In one study, for example, caffeine was found to inhibit the production of inflammatory cytokines in lung cells.

Overall, the evidence suggests that caffeine can have a number of positive effects on the lungs, including bronchodilation, increased respiratory rate, improved lung function, and reduced risk of respiratory disease.