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Updated on September 29, 2023
Smoking kills about 480,000 people every year and is a contributor to three of the five leading causes of death in the United States: heart disease, cancer, and stroke. If you need even more reasons to quit, here are four surprising facts to consider—plus one piece of good news.
Smoking changes your DNA
Research has shown that smoking causes changes to the DNA of cells through a process called methylation. Methylation is when DNA is chemically modified in a way that causes changes to remain even when cells divide and reproduce. DNA methylation may work by turning on and off the production of proteins encoded by the gene.
One 2016 study published in Circulation: Cardiovascular Genetics that looked at cigarette smokers suggested that the changes to cells’ DNA caused by methylation may remain for more than 30 years in some cases. Several more recent studies have further described the effects of methylation.
A 2021 meta-analysis published in Clinical Epigenetics demonstrated how certain methylated biomarkers could show whether a person had been exposed to cigarette smoke. A 2022 review published in the International Journal of Molecular Sciences confirmed that DNA methylation caused by smoking can be a marker for diagnosing and treating smoking-related cancers.
Smoking may cause methylation in about one-third of known genes. The one glimmer of hope? Most of these genes may go back to normal by five years after quitting smoking.
Cigarette smoke contains an obscene number of chemicals
Here are some of the 7,000 chemicals contained in either tobacco or tobacco smoke:
- Nicotine, a potent insecticide
- Acetone, also found in nail polish remover
- Arsenic, also found in rat poison
- Butane, also found in lighter fluid
- Carbon monoxide, also found in car exhaust
- Formaldehyde, also found in embalming fluid
- Lead, also found in batteries
- Tar, also found in blacktop road surfaces
According to the U.S. Environmental Protection Agency, cigarettes also contain radioactive materials, including toxic polonium-210 and lead-210, which are byproducts of radon found in fertilizers and soil. These may remain on tobacco leaves during processing.
If you think e-cigarettes or vaping are less toxic, think again. In addition to containing nicotine, the flavoring chemicals in vapes can irritate the lungs. The vape’s carrier, or liquid (such as propylene glycol) can also be toxic and irritating. When heated, that liquid may also create traces of acetone and formaldehyde. To top it off, the metal tanks used in vapes can degrade after many rounds of heating, which may release toxic metals into your lungs over time.
Smoking can cause conception and sexual problems
In 2011, a landmark review of 50 years of studies confirmed that smoking during pregnancy can cause major birth defects. Many smokers don’t even make it as far as having children, however. Smoking can impair proper hormone production and cause damage DNA in sperm, reducing the chances of conceiving and potentially resulting in genetic mutations in children.
Impaired hormone production resulting from smoking can also cause sexual dysfunction in people assigned female at birth. Smoking also contributes to erectile dysfunction in those assigned male at birth.
Smoking affects your entire body
You probably already know that smoking can cause or contribute to lung cancer, heart disease, and stroke. But what about the rest of the body?
According to the Centers for Disease Control and Prevention (CDC), smoking raises your risk of type 2 diabetes by 30 to 40 percent. Smoking also hurts your eyes. If you smoke, your risk of age-related macular degeneration doubles and you’ll be two to three times more likely to get cataracts.
Smoking can even aggravate your back. Smoking has been found to be a risk factor for developing chronic low back-pain in some research studies.
Smoking also raises your risk for other cancers throughout the body. For example, smokers have roughly twice the risk of cervical cancer as those who don’t smoke, and secondhand smoke also increases the risk. Other cancers caused by smoking include (but are not limited to) cancers of the esophagus, bladder, blood, liver, pancreas, mouth, kidney, and colon.
Smoking rates are at an all-time low
According to the CDC, in 2021 (the most recent year for which data were available), 11.5 percent of Americans aged 18 or older smoked. That’s about 28.3 million people. It’s still a large number, but the good news is that the percentage has been declining. In 2005, by comparison, nearly 21 percent of U.S. adults smoked.
More good news: Many of the health risks caused by smoking go away after you quit.
- Your risk of a heart attack goes down dramatically one to two years after quitting.
- In three to six years after quitting, your added risk of coronary heart disease is halved.
- In five to 10 years of quitting, your added risk of mouth and throat cancers are half of what they were when you smoked.
- In 10 years of quitting, your added risk of lung cancer decreases by half and your risk of bladder, esophagus, and kidney cancers lowers.
- In 15 years after quitting, your risk of coronary heart disease is the same as someone who doesn’t smoke.
Some benefits happen even quicker: After quitting, your sense of smell and taste will improve right away, you’ll experience less coughing and shortness of breath, and your circulation will improve,
Don’t wait. Quit today.
