It's common wisdom that if you smoke enough you'll eventually develop a smokers cough, and the chances are also pretty good you could end up with Chronic Bronchitis. A new study purports to prove that smoking itself causes excess sputum production.
A new study published online ahead of the print edition of American Journal of Respiratory and Critical Care Medicine reports that chemicals in cigarette smoke suppress a protein called Bik in your lungs that prevents the natural death of mucus producing cells.
It has been known for years that smoking destroys cilia in the lungs that are the main mechanism for bringing up excess secretions to the upper airway to be swallowed, why the increased sputum production was unknown until this recent study.
Previous such studies found that overproduction of mucus cells is in the large and small airways of people who smoke, and this chronic mucus production is responsible for airway obstruction, reduced lung function, and increased pathogens in the lungs that cause things like pneumonia.
The researchers, who studies samples from human and mouse lung tissue exposed to cigarette smoke, also showed that bik protein levels remained low even after the person (or mouse in some cases) was no longer exposed to cigarette smoke.
So permanent damage to the lungs exposed to cigarette smoke is highly likely. This might also explain why asthmatics exposed to cigarette smoke have worse asthma, because I'm sure second hand cigarette smoke decreases the bik protein in anyone exposed to cigarette smoke.
Further studies will be needed to further this research.