There’s so much more to smoking than nicotine
While most people are aware that smoking increases the chances of lung cancer, what many don’t know is that it’s been found to be a cause of 13 types of cancer including pancreatic, stomach, bladder, cervical, oral, and kidney malignancies. 30% of cancer deaths can be attributed to smoking.
Even if it doesn’t cause lung cancer, it can damage the lungs in other ways. It injures the airways through chemicals released and through the increased heat produced. Chemicals released from a burning cigarette include carbon monoxide, hydrogen cyanide, nitrogen dioxide and nicotine from tobacco tar. One of the problems smoking causes is constriction of the smooth muscles around the bronchial tubes that bring air into and out of the air sacs (where oxygen is absorbed into the blood and carbon dioxide released). Bronchial constriction narrows the airways so they don’t carry as much air.
Cigarette smoke also causes the mucosal lining of the airways to become inflamed, destroying the ciliated cells that look like they have little hairs. These ciliated cells sweep the mucous out of the airways. That is an important function because mucous traps bacteria, harmful chemicals in the air and other harmful things. The ciliated cells work together to move the mucus up to the throat where they are spit out or swallowed so they can’t damage the lungs. When that benefit is impaired or lost with long-term cigarette smoke exposure, chronic bronchitis can develop.
Emphysema is another type of injury from cigarette smoke. It affects the tinniest of branched airways, called terminal bronchi. Those airways lead to the air sacs. When these bronchi become weakened, they collapse before the air sacs empty during exhalation. The trapped air overstretches alveoli (air sacs), making them thin and prone to rupture. After many of these little air sacs have broken, the surface area for gas exchange is decreased. As with chronic bronchitis, if the smoking doesn’t stop, emphysema will progress.
Chemicals in cigarette smoke can damage the lining of arteries, allowing plaque to develop and narrow them. Affected arteries carry less blood and if the plaque builds up too much or ruptures, a blood clot forms and a section of the heart dies. This is a heart attack. Among those who have a heart attack after age 65, if they smoke, they’re 60% more likely to die from it.
Alzheimer’s disease and other causes of dementia are much more common in smokers. Cataracts are 2 to 3 times more likely to develop in smokers.
But perhaps the most tragic statistics related to smoking are for non-smokers exposed to cigarette smoke. Regular second-hand smoke causes a 20 to 30% greater chance of developing coronary artery and lung cancer. There’s evidence it also increases the risk of breast cancer, asthma and COPD.
Information for this article was obtained from the American Cancer Society, American Lung Association, and Centers for Disease Control.