smoking man
Smoking cigarettes is universally regarded as bad for health, but not everybody who smokes develops cancer or other diseases linked to the habit. New research shows that a proportion of lifelong smokers live to extreme ages despite the long list of negative effects cigarettes have on the body.

Researchers found a set of genetic markers that promote longevity in cells and mitigate damage to them, which may be the explanation for preventing diseases tied to cell dysfunction.

"Many of these markers are in pathways that were discovered to be important for aging and lifespan in animal models," said Dr. Morgan Levine, a researcher at the University of California Los Angeles, in a press release. "There is evidence that these genes may facilitate lifespan extension by increasing cellular maintenance and repair. Therefore, even though some individuals are exposed to high levels of biological stressors, like those found in cigarette smoke, their bodies may be better set up to cope with and repair the damage."

Comment: One wonders which came first; the genetic markers or the smoking? If the latter, did the smoking cause the genes to change through epigenetic effects?

Researchers used data from the Health and Retirement Study to conduct a genome-wide study comparing 90 long-lived smokers with 730 smokers between the ages of 52 and 69. They found a set of 215 nucelotide polymorphisms, which together make up a functional interaction network that allows people with them to better withstand environmental damage and mitigate the damage to cells.

The set of nucleotide polymorphisms was then used to compare the smokers with 6,447 non-smokers, which showed people with the polymorphisms were 22 percent more likely to survive into their 90s and and triple the chance of making it 100 years old. The same comparison also found the group with the genetic differences had an 11 percent reduction in cancer prevalence.

The set of genetic differences may play into future research working to prevent cancer because genetic instability is a key part of developing tumors, researchers said.

The study is published in The Journals of Gerontology.