Heavy Smokers Who Cut Back Still Take In More Toxins Than Light Smokers
who have reduced their number of daily cigarettes still experience
significantly greater exposure to toxins per cigarette than light
smokers, according to a new study by researchers at the University of
smokers in the two groups smoked as few as five cigarettes a day, heavy
smokers who reduced their cigarette intake experienced two to three
times the amount of total toxin exposure per cigarette when compared
with light smokers, researchers reported in the December issue of
Cancer Epidemiology, Biomarkers & Prevention.
researchers observed that the more that heavy smokers reduced their
smoking, the more likely they were to increase their exposure to
toxicants per cigarette presumably because they took more frequent
puffs or inhaled deeper or longer on each cigarette, a process referred
to as "compensatory smoking." As a result, smokers who decreased their
smoking to as little as one to three cigarettes per day experienced a
four- to eight-fold increased exposure to toxins per cigarette as
compared with light smokers.
smoking occurs because smokers are trying to maintain a specific level
of nicotine in their bodies, said Dorothy K. Hatsukami, Ph.D., lead
author of the study and director of the University’s
Transdisciplinary Tobacco Use Research Center in Minneapolis. Other
factors, such as the sensory aspects of smoking, also may play a role
in compensatory smoking, Hatsukami says.
results are consistent with other studies that show that people who
decrease their smoking by 50 percent or more don’t experience a
comparable reduction in risk for lung cancer because they tend to smoke
their fewer cigarettes more intensely," she says. "The best way to
lower the risk for premature death is to stop smoking altogether."
study, Hatsukami and colleagues compared a group of 64 people
participating in two smoking reduction intervention studies and who
reduced their smoking to levels similar with a group of 62 light
smokers. The researchers created a mathematical formula to calculate
the degree of smoking compensation in reducers compared with light
smokers. As part of the formula, they measured a biological marker,
total NNAL, which indicates the amount of exposure to the
tobacco-specific lung cancer-causing agent NNK.
smokers averaged age 48, were 53 percent female and smoked an average
of 5.6 cigarettes a day. The reducers averaged age 51, were 39 percent
female and smoked an average 26 cigarettes per day prior to cigarette
reduction. All of the reducers studied decreased their smoking by at
least 40 percent andsmoked five cigarettes per day within six months of
enrolling in the study.
indicated that the average level of NNAL for reducers was more than
twice that of light smokers, even when the two groups smoked about the
same number of cigarettes per day. The amount of smoking reduction was
shown to be a strong predictor of compensatory smoking, with greater
cigarette reduction associated with more compensation.
says heavy smokers fare better health-wise by quitting smoking than
decreasing their cigarette intake: "Although light smokers have lower
levels of disease risk than heavy smokers, a low rate of smoking still
confers increased risk compared to non-smokers and quitters."
In a previous
study of smoking reduction using nicotine replacement therapies such as
gum or patches, the researchers observed that smokers who reduced their
cigarette intake by 73 percent only experienced a 30 percent reduction
in carcinogens because of compensatory smoking. Another study showed
that a reduction of 62 percent in tobacco consumption was associated
with only a 27 percent reduction in lung cancer risk.
The research was supported by the National Institute on Drug Abuse.
Source: American Association For Cancer Research, www.aacr.org