If you smoke, best to wait a bit after
waking in the morning
The sooner a person
smokes a cigarette upon waking in the morning, the more likely he or she is to
acquire lung or oral cancer, according to Penn State researchers.
"We found that
smokers who consume cigarettes immediately after waking have higher levels of
NNAL -- a metabolite of the tobacco-specific carcinogen NNK -- in their blood
than smokers who refrain from smoking a half hour or more after waking, regardless
of how many cigarettes they smoke per day," said Steven Branstetter,
assistant professor of biobehavioral health.
According to Branstetter, other research has shown that NNK (4-(methylnitrosamino)-1-[3-pyridyl]-1-butanone) induces lung tumors in several rodent species. Levels of NNAL (4-(methylnitrosamnino)-1-(3-pyridyl)-1-butanol) in the blood can therefore predict lung cancer risk in rodents as well as in humans. In addition, NNAL levels are stable in smokers over time, and a single measurement can accurately reflect an individual's exposure.
Branstetter and his
colleague Joshua Muscat, professor of public health sciences, examined data on
1,945 smoking adult participants from the National Health and Nutrition
Examination Survey who had provided urine samples for analysis of NNAL. These
participants also had provided information about their smoking behavior,
including how soon they typically smoked after waking.
The researchers found
that around 32 percent of the participants they examined smoked their first cigarette
of the day within 5 minutes of waking; 31 percent smoked within 6 to 30 minutes
of waking; 18 percent smoked within 31 to 60 minutes of waking; and 19 percent
smoked more than one hour after waking. In addition, the researchers found that
the NNAL level in the participants' blood was correlated with the participants'
age, the age they started smoking, their gender and whether or not another
smoker lived in their home, among other factors.
The team published its
results in the March 29 issue of the journal Cancer, Epidemiology, Biomarkers
and Prevention.
Read more at EurekAlert.
