Dear Dr. Jeff: We all know heavy smoking is very bad for you. But what about one or two cigarettes a day? M.P.
Dear M.P.: Although there is a definite dose-response relationship between smoking and its harmful effects, smoking even one or two cigarettes per day poses very definite health risks and causes very definite harm.
Cigarette smoke consists of a complex mixture of over 4,000 organic and inorganic compounds, generated by the combustion of tobacco and additives. They include cyanide, benzene, formaldehyde, methanol (wood alcohol), acetylene (the fuel used in welding torches), and ammonia.
Many of these compounds cause heart and lung disease. Forty-three of these compounds cause cancer. Together, they make cigarette smoke a Class A carcinogen, a substance that is dangerous in any amount. There is no such thing as a safe level of exposure to a Class A carcinogen, no matter how small, no matter how infrequent.
There are other shorter-term factors to consider as well.
Some of smoking's immediate harm comes from just inhaling hot smoke. Our respiratory trees are lined with millions of tiny hair cells called cilia, which rhythmically beat up out of our lungs the foreign particles we normally happen to breathe in. Cilia constitute a primary line of defense against respiratory pathogens and irritants. But cilia are very sensitive to heat. In fact, the heat from the smoke of a single cigarette will paralyze them for a full day. That's why smokers wake up with a "smoker's cough." Their cilia can't clean them out overnight, and they're left to try to cough themselves clear in the morning.
Another consideration: smoking a cigarette or two per day will likely expose others to second-hand smoke, itself a Class A carcinogen and the cause of a great deal of harm to others. Others, I needn't remind you, who have themselves chosen not to smoke cigarettes. Secondhand smoke is the third leading cause of preventable death in the U.S.
And then there's the risk of addiction. Nicotine is very addictive. Very addictive.
It is obviously the reason all regular smokers smoke and the same reason it becomes so hard to quit. After a time, it's easier to quit alcohol or heroin than cigarettes.
Few people can smoke only one or two cigarettes per day for long. Nicotine has greater than a 50 percent addiction rate over time. That means that after a year, over half of those who started off only smoking occasionally become full-time smokers?and full-time nicotine addicts.
Over a second year of casual smoking, more than half of the rest become addicted, and so on.
Smoking one or two cigarettes per day is smoking one or two cigarettes too many.
The harm is real. The risks are considerable.
Why go there?
Be well!
Jeff Benson, MD
Dudley Coe Health Center