Study Finds Smoking Alters Over 7,000 Genes
HealthDay News — Smoking cigarettes can leave a lasting imprint on human DNA, altering more than 7,000 genes in ways that may contribute to the development of smoking-related diseases, according to research published online September 20 in Circulation: Cardiovascular Genetics.
Stephanie London, MD, DrPH, deputy chief of the epidemiology branch of the U.S. National Institute of Environmental Health Sciences, and colleagues reviewed results from blood samples taken from 15,907 people in 16 prior studies. London's team compared DNA methylation sites in current and former smokers to those who never smoked.
In addition to finding that smoking-related DNA sites were linked with more than 7,000 genes – about one-third of known human genes – the researchers learned that some DNA methylation sites persisted even three decades after quitting. The team also found that for those who stopped smoking, most genes "recovered" within five years of quitting.
"Cigarette smoking has a broad impact on genome-wide methylation that, at many loci, persists many years after smoking cessation," the authors write. "Many of the differentially methylated genes were novel genes with respect to biologic effects of smoking, and might represent therapeutic targets for prevention or treatment of tobacco-related diseases. Methylation at these sites could also serve as sensitive and stable biomarkers of lifetime exposure to tobacco smoke."