A 40-year study conducted by Tel Aviv University researchers has proven that
giving up smoking lowers the risk of disease, increases life expectancy and
improves the quality of life. But while complete cessation is preferable, those
who claim to be unable to kick the habit enjoy health benefits from lowering
their cigarette consumption, the study showed.
Vicki Myers, a researcher
at TAU’s Sackler Faculty of Medicine, and Dr. Yariv Gerber and Prof. Uri
Goldbourt of TAU’s School of Public Health examined survival and life expectancy
rates of smokers who reduced their cigarette consumption instead of quitting
entirely. Their data covered an unusually long period of more than four
While quitters were found to have the biggest improvement in
mortality rates – a 22 percent reduced risk of an early death, compared to
smokers who maintained their smoking intensity – reducers also saw significant
benefits, with a 15% reduced risk. These results show that smoking less is a
valid risk-reduction strategy, Myers said, adding that formerly heavy smokers
had the most to gain from smoking reduction.
This research has just been
published in the American Journal of Epidemiology. To examine the impact of
changes in smoking intensity over time, the researchers drew on a sub-cohort of
the Israeli Ischemic Heart Disease Study, comprising a database of 4,633 working
Israeli men, all smokers at baseline, with a median age of 51 at recruitment.
Interviews regarding their smoking habits took place in 1963 and again in 1965,
and participants’ mortality status was followed for a period of up to 40
During their first interview, participants were placed in
categories by daily cigarette consumption – no cigarettes, one to 10 cigarettes,
11 to 20 cigarettes and more than 21. In the second interview, researchers noted
whether an individual had increased, maintained, reduced or ceased smoking
during the intervening two years, with “increasing” or “reducing” defined as
moving up or down at least one category of cigarette consumption within this
Unsurprisingly, quitters were the best off in the long term, with
a 22% reduction in overall mortality. Those who reduced their smoking by one
category or more were seen to have a 15% decrease in overall mortality risk and
a 23% reduced risk of cardiovascular mortality.
In addition, the
researchers measured the participants’ survival to the age of 80. Quitters saw a
33% increased chance of survival to 80 years of age, and reducers a 22%
Myers says that their study, one of the few to take
smoking reduction into account, shows that reduction is certainly better than
doing nothing at all. She credited the long-term follow- up period for
demonstrating the effect of smoking reduction where other studies have not,
because damage done by smoking, and subsequently the recovery process, has a
long time line.
One of the important lessons of their study, said Myers,
is that it is never too late to tackle your smoking habit. Participants of this
study, who were on average 50 years old when the study began, were still able to
quit or reduce their smoking and see long-term benefits from their efforts.
Though reduction is a controversial policy – some health professionals believe
it dilutes the message of cessation – smokers should take any steps possible to
improve their long-term health, she advised.