First study to show alteration in the function of genes in the lungs resulting from secondhand and low-level smoking
Casual smokers may think that smoking a few cigarettes a week is "no big deal." But according to new research from physician-scientists at NewYork-Presbyterian Hospital/Weill Cornell Medical Center, having an infrequent smoke, or being exposed to secondhand smoke, may be doing more harm than people may think. The findings may further support public smoking bans, say the authors.
According to a new study published today in the American Journal of Respiratory and Critical Care Medicine, being exposed to even low-levels of cigarette smoke may put people at risk for future lung disease, such as lung cancer and chronic obstructive pulmonary disease (COPD).
Epidemiological studies have long shown that secondhand smoke is dangerous, but there have never been conclusive biological tests demonstrating what it does to the body at a gene function level, until now.
"Even at the lowest detectable levels of exposure, we found direct effects on the functioning of genes within the cells lining the airways," says Dr. Ronald Crystal, senior author of the study and chief of the division of pulmonary and critical care medicine at NewYork-Presbyterian/Weill Cornell and chair of the department of genetic medicine at Weill Cornell Medical College in New York City.
Dr. Crystal explains that genes, commonly activated in the cells of heavy smokers, are also turned on or off in those with very low-level exposure.
"The genetic effect is much lower than those who are regular smokers, but this does not mean that there are no health consequences," says Dr. Crystal. "Certain genes within the cells lining the airways are very sensitive to tobacco smoke, and changes in the function of these genes are the first evidence of 'biological disease' in the lungs or individuals."