Listen Up, Smokers: Cutting Back Isn't Good Enough
If smoking 40 cigarettes a day is bad, you might think that smoking 20 would be half as bad. But reducing tobacco use doesn't reduce cancer risk by the same amount, and researchers have provided a clue as to why: Smokers who cut back compensate for the drop in nicotine by inhaling more smoke from each cigarette.
Researchers from the University of Minnesota looked at two groups of people: 64 heavy smokers who were cutting back their use, and 62 light smokers. Both groups smoked the same number of cigarettes, and their urine was tested for NNAL, a chemical that indicates a person's exposure to the toxins in tobacco. The average level of NNAL in the heavy smokers who had cut back was more than twice that of the consistently light smokers. The findings were published in the December edition of Cancer Epidemiology Biomarkers & Prevention.
"Reduction in itself may not cut the risk of cancer," says Dorothy Hatsukami, director of the university's Transdisciplinary Tobacco Use Research Center and an author of the study. This work follows a study by Norwegian researchers published last month showing that heavy smokers who cut their consumption in half had the same mortality rates as people who didn't cut back. Only the people who cut back and then quit entirely had a lower risk of death from any cause, including cancer and heart disease. Another study published last year found that cutting tobacco consumption by 62 percent reduces the risk of lung cancer by just 27 percent.
The latest study didn't look at what brand or variety of cigarettes people were smoking, so it's possible that the reducers were using higher-tar cigarettes. However, the authors wrote, other studies haven't found significant differences in exposure to tobacco toxins between regular, light, and ultra light cigarettes, so that's unlikely to have blurred the results.
This all might sound highly discouraging to anyone who's trying to quit; cutting back sounds a lot easier than going cold turkey. But, reduction can still be a stepping-stone, says Hatsukami. Just be sure to work toward stopping entirely.