Smoking and lung cancer: reducing consumption is not enough, we need to stop smoking

For most smokers, the fact of reducing cigarette consumption is reduced exposure to carcinogens than moderate and transitory, warn the authors of a U.S. study published in the "Journal of the National Cancer Institute."

Smoking being the cause of 90% of lung cancers, U.S. researchers have tried to assess the impact of the reduction in daily cigarette consumption on the risk of developing this disease.

With this in mind, Dr. Stephen Hecht and colleagues from the center of research on smoking, which depends on the Faculty of Pharmacy of the University of Minnesota, Minneapolis, sought to determine if this method of weaning was associated with a reduction exposure to a carcinogenic molecule characteristic of lung cancer contained in cigarette smoke, the NKK.

To do this, they measured the presence of degradation products of this molecule in the urine of 151 smokers enrolled in a program to reduce their cigarette consumption.

Developed over a period of six months, weaning protocol expected a quarter of the reduction in cigarette consumption during the first two weeks, then half for the next two weeks. Participants were then between the fourth and sixth week, down three quarters consumption and maintain this goal until the 26th week.

Also the amount of by-products of NKK, the researchers also determined at each sampling carried out within the six months of withdrawal, the rate of anatabine. Thus, the presence of the other compound of cigarette smoke allowed them to check whether the participants actually reduced their consumption.

Despite the possibility of using nicotine replacement therapy, only 92 of the 151 participants were able to reduce their consumption. And if significant reductions in serum metabolites NKK were observed parallel to the gradual withdrawal, they proved generally modest and often transient.

Thus, for participants who managed to reduce by 90% the consumption of cigarettes over a period of twelve weeks (from 24.7 to 2.6 per day on average), the average rate of metabolites NKK did not even not halved (46%), the authors found.

According to them, smokers reduce their cigarette consumption would change their smoking to successfully maintain their daily dose of nicotine. Inhaling more deeply and smoke more deeply, so they would keep the amount of toxic substances absorbed despite the decrease in the number of daily cigarettes.

For most smokers, the act of simply reduce the daily consumption would be sufficient to reduce the risk of developing lung cancer and a final withdrawal would therefore be a more effective option to prevent the disease.