Smoking soon after waking up could increase cancer risk
From Chicago Tribune:
If that first cigarette is smoked within the first half hour of waking up, beware. That could indicate being at higher risk for lung, head and neck cancers.
Two studies released online Monday in the journal Cancer tracked smoking habits of thousands of smokers to see if those routines made a difference in their chances of getting certain types of cancer. How much time it takes to smoke the first cigarette after waking is considered one measure of nicotine addiction.
In the study looking at links between early smoking and lung cancer, researchers analyzed data on 4,775 people with lung cancer and 2,835 regular smokers who comprised the control group. Participants who started puffing 31 to 60 minutes after waking were 1.31 times more likely to develop lung cancer than those who started smoking an hour or more after waking up. People who lit up within half an hour of waking were 1.79 times more likely to develop lung cancer that those who waited an hour.
In the study examining the association between early smoking and head and neck cancers, the pool of participants included 1,055 people with head and neck cancers and a control group of 795 cigarette smokers. In this group, those who smoked their first cigarette between 31 to 60 minutes after waking were 1.42 times more likely to develop those types of cancers compared to men and women who smoked their first cigarette an hour or more upon waking. Those who grabbed their first cigarette within 30 minutes after waking were 1.59 times more likely to develop head and neck cancer compared to the group who waited an hour.
Among types of head and neck cancers, the strongest association was noticed between smoking within a half-hour of waking and cancer of the pharynx, and the weakest link was with cancers of the tongue.
How soon people light up after waking, the authors noted, may be due to genetic differences in nicotine addiction, socioeconomic factors, or both working together.
"These smokers have higher levels of nicotine and possibly other tobacco toxins in their body, and they may be more addicted than smokers who refrain from smoking for a half hour or more," said Joshua Muscat of the Penn State College of Medicine, in a news release. Muscat, lead author of both studies, added, "It may be a combination of genetic and personal factors that cause a higher dependence to nicotine."