Research: Cigarettes permanently damage smokers’ DNA

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OK, smoking gives you lung cancer, it makes you impotent, it can lead to Alzheimer’s…

… want another reason to quit smoking? It also permanently damages smokers’ DNA. Put those words together in a sentence … permanently …. damaged … DNA.

This is something I was somewhat already aware of — it’s the DNA damage smoking causes that has a lot to do with smokers developing lung cancer. I know I’m seriously oversimplifying it, but it comes down to smoking breaking the DNA strands, which leads to cell mutation, which leads to tumours. Keep in mind, cigarette smoke actually contains Polonium-210, a radioactive isotope.

I don't know what's going on in this photo, but I thought it was funny.
I don’t know what’s going on in this photo, but I thought it was funny.

According to this research done at Harvard Medical School, the damage to a smokers’ DNA does fade over time if a smoker quits. However, it does not completely vanish. There ain’t no undoing some of the damage. It lingers … for life.

From an NBC News article:

The marks are made in a process called methylation, which is an alteration of DNA that can inactivate a gene or change how it functions — often causing cancer and other diseases.

“Our study has found compelling evidence that smoking has a long-lasting impact on our molecular machinery, an impact that can last more than 30 years,” said Roby Joehanes of Hebrew SeniorLife and Harvard Medical School.

Heart disease and cancer are both caused by genetic damage — some of it inherited, but most of it caused by day-to-day living. Smoking is one of the biggest culprits.

“The encouraging news is that once you stop smoking, the majority of DNA methylation signals return to never-smoker levels after five years, which means your body is trying to heal itself of the harmful impacts of tobacco smoking,” Joehanes said.

Smoking scars DNA in clear patterns, researchers reported Tuesday. Most of the damage fades over time, they found — but not all of it.

Their study of 16,000 people found that while most of the disease-causing genetic footprints left by smoking fade after five years if people quit, some appear to stay there forever.

Image: A customer smokes a cigarette in a cafe
A customer smokes a cigarette in a cafe in Prague, Czech Republic, May 25, 2016.DAVID W CERNY / Reuters, file

The marks are made in a process called methylation, which is an alteration of DNA that can inactivate a gene or change how it functions — often causing cancer and other diseases.

“Our study has found compelling evidence that smoking has a long-lasting impact on our molecular machinery, an impact that can last more than 30 years,” said Roby Joehanes of Hebrew SeniorLife and Harvard Medical School.

Heart disease and cancer are both caused by genetic damage — some of it inherited, but most of it caused by day-to-day living. Smoking is one of the biggest culprits.

“The encouraging news is that once you stop smoking, the majority of DNA methylation signals return to never-smoker levels after five years, which means your body is trying to heal itself of the harmful impacts of tobacco smoking,” Joehanes said.

The team examined blood samples given by 16,000 people taking part in various studies going back to 1971. In all the studies, people have given blood samples and filled out questionnaires about smoking, diet, lifestyle and their health histories.

Among quitters, most of these changes reverted to the patterns seen in people who never smoked after about five years, the team reported in the American Heart Association journal Circulation: Cardiovascular Genetics.

But smoking-related changes in 19 genes, including the TIAM2 gene linked to lymphoma, lasted 30 years, the team found.

DNA damage. Some pretty heavy and scary stuff. And it makes me also worry what DNA damage might be caused by breathing in secondhand smoke.

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