How smoking damages DNA within minutes, research shows

CIGARETTES start to destroy a smoker’s
Deoxy ribo-Nucleic Acid (DNA), genetic
material, within minutes of inhaling, new
research indicates, suggesting that the habit
causes immediate genetic damage and
quickly raises the short-term risk for cancer.
“The results reported here should serve as a
stark warning to those, who are
considering starting to smoke cigarettes,”
lead study author Stephen S. Hecht, from the
Masonic Cancer Center and Department of
Pharmacology at the University of
Minnesota in Minneapolis, said in a news
release from the American Chemical Society.
Hecht and his colleagues reported their
observations in the current issue of the
journal Chemical Research in Toxicology.
In their research, the investigators focused
on a class of cancer-causing culprits found
in cigarette smoke called polycyclic aromatic
hydrocarbons, or PAHs.
PAHs are known to inflict damage on DNA
and are therefore thought to play a large
role in the onset of lung cancer, a disease
that the researchers pointed out has been
linked to the loss of 3,000 lives a day
worldwide, mostly as a consequence of
smoking.
To date, however, little had been known
about the exact mechanism by which PAH
exposure causes disease.
To better understand the risks, Hecht ’s team
conducted what they called a “unique”
analysis, by labeling and tracking a single
PAH — phenanthrene — through the bodies
of 12 volunteer smokers.
The study authors noted that this approach
was “the first to investigate human
metabolism of a PAH specifically delivered
by inhalation in cigarette smoke, without
interference by other sources of exposure
such as air pollution or the diet. ”
The results, having rapidly transformed in
the body into a known toxin, the PAH in
question began to cause havoc on the DNA
of the smokers within just 15 to 30 minutes
after smoking.
The velocity of the cancer-causing process
surprised the research team. They said the
speed with which the potentially lethal DNA
assault began was comparable to having
injected the PAH directly into an individual ’s
bloodstream.