Cancer Research News
Smokers Who Cut Back on Cigarettes May Negate Benefit through Compensatory Smoking
PHILADELPHIA (December 11, 2006) – Heavy 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 Minnesota.
Even when 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 report in the December issue of
Cancer Epidemiology, Biomarkers & Prevention.
In addition, 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.
Compensatory smoking occurs because smokers are trying to maintain a
specific level of nicotine in their bodies, says 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.
“These 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.”
For the 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.
The light 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 and smoked five cigarettes per day within six
months of enrolling in the study.
Results 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.
Hatsukami 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
The research was supported by the National
Institute on Drug Abuse.
Source: American Association for Cancer Research
Exercise Can Reduce a Smoker's Lung Cancer Risk, but Quitting Smoking Is
Still Most Important (Dec 2006)
Successful Lung Cancer Surgery Not Enough to Break Nicotine Dependence
in Many Smokers (Dec 2006)