Even brief exposure to tobacco smoke causes immediate harm to the body, damaging cells and inflaming tissue in ways that can lead to serious illness and death, according to the U.S. Surgeon General's report on tobacco, released in December 2010.
Every exposure to tobacco, from occasional smoking or secondhand smoke, can damage DNA in ways that lead to cancer.
“Low levels of smoke exposure, including exposures to secondhand tobacco smoke, lead to a rapid and sharp increase in dysfunction and inflammation of the lining of the blood vessels, which are implicated in heart attacks and stroke,” said the report. “The chemicals in tobacco smoke reach your lungs quickly every time you inhale. Your blood then carries the toxicants to every organ in your body.”
Studies can now measure the immediate changes in our bodies as we smoke a single cigarette, from a rise in blood pressure to a change in the gases in our blood stream.
Here's what happens when we smoke a cigarette:
- Although we may feel more relaxed as we smoke, our blood pressure and heart rate both increase, the heart pumps differently, and the blood flow to the capillaries decreases.
- Blood carbon monoxide levels increase. "Carbon monoxide takes the place of oxygen in some of your red blood cells, and it sticks on to the red cells for days, preventing oxygen from being carried by these cells.”
- Other changes happen in our airways: the little finger-like cilia which keep airways clear of phlegm are 'stunned' by chemicals in the smoke and tiny muscles in our airways contract, constricting them.
- There are also measurable changes in the immune system.
These and other changes have a cumulative effect and over time they can eventually lead to cancer (including cancer of the lung, pancreas, esophagus, and bladder) as well as non-cancerous, but potentially lethal, conditions such as heart and vascular disease and lung diseases like emphysema.
And it's not just cancer and the health of your heart and lungs that you have to worry about.
A recent review of several studies found that light smoking was connected to a host of other illnesses: cataracts, reduced fertility, an increased risk of an ectopic pregnancy (where the pregnancy develops outside the uterus) and weak bones.
"Tobacco smoke damages almost every organ in your body," says Surgeon General Regina Benjamin. In someone with underlying heart disease, she says, "One cigarette can cause a heart attack."
While the report focuses on the medical effects of smoke on the body, it also sheds light on why cigarettes are so addictive: They are designed to deliver nicotine more quickly and more efficiently than cigarettes did decades ago.
Recent changes in the design and ingredients in cigarettes have made them more likely to hook first-time users and keep older smokers coming back, Benjamin says. Changes include:
•Ammonia added to tobacco, which converts nicotine into a form that gets to the brain faster.
•Filter holes that allow people to inhale smoke more deeply into the lungs.
•Sugar and "moisture enhancers" to reduce the burning sensation of smoking, making it more pleasant, especially for new cigarette users.
"This is the first report that demonstrates that the industry has consciously redesigned tobacco products in ways that make them even more attractive to young people," says Matthew Myers of the Campaign for Tobacco-Free Kids.
As ex-smokers are fond of saying, cigarettes travel in packs. Research shows that upwards of 90% of ex-smokers who smoke one cigarette after quitting can't stop there and end up in a full-blown smoking relapse.
The only way to keep the beast at bay is to keep all Nicotine out of your system. If you decide to go ahead and smoke just one, chances are you'll be back to smoking as much as you used to again soon.