At Least Reduce Smoking If You Can’t Quit


The research team (Samsung Medical Center and Seoul National University Hospital Gangnam Center) investigated subjects that had undergone health screening in 2009 and had a follow-up screening in 2011 to see whether the effects of reduction, cessation, and continuation of smoking had any effect on cancer development. Based on the average number of cigarettes smoked per day, they were categorized into groups of quitters, reducers, sustainers, and increasers.

The study participants involved 50,869 people over 40 years old; mean follow-up period of 6.1 years


Those who succeeded in quitting smoking were 20.6%, and those who reduced their smoking were 18.9%. Nearly half, 45.7%, continued to smoke the same amount. Those who smoked 20% more than before were at 14.8%.


The research team compared and analyzed the cancer risk between these groups, and compared to the sustainers group, those who succeeded in quitting smoking had the lowest risk of cancer. It lowered the risk of all cancers by 6%, smoking-related cancers by 9%, and lung cancer by 21%.

Even if you couldn't quit smoking, reducing the amount of smoking had an effect on lowering the risk of cancer. Compared to the sustainers group, those who reduced more than 50% of smoking lowered the overall cancer risk by 4%, smoking-related cancer by 5%, and lung cancer by 17%.


Furthermore, as a result of additional analysis, for those who resumed smoking after quitting, the risk of smoking-related cancer increased by 19% and lung cancer by up to 48% compared to those who continued to quit smoking even if the smoking amount was reduced by more than 50% of the previous smoking amount.


The result of this study was published in Cancer, a journal of the American Cancer Society.