Smokers who light up first thing in the morning are more likely to develop lung cancer and tumors of the head and neck, compared with people who wait at least an hour after rolling out of bed to smoke, according to a pair of studies published online by the journal Cancer.
Early morning smoking, defined as lighting up within the first half-hour of waking, was associated with a 79% increase in likelihood that a smoker would be diagnosed with lung cancer, compared with those who waited at least an hour. Early smokers were also 59% more likely to develop head or neck cancer than those who waited an hour or longer.
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People who smoked their first cigarette between 31 and 60 minutes after waking also had increased risks of cancer — a 42% greater risk of lung cancer and a 31% higher risk of head and neck cancer — compared with those who smoked later.
The new studies, led by the same research team, looked at two separate cohorts that included only current or former smokers (no never-smokers): one study included 1,055 head and neck cancer patients and 795 controls who did not have cancer; another focused on 4,775 newly diagnosed lung cancer patients and 2,835 controls. All were seen at New York-area teaching hospitals.
The risk of lung and head and neck cancers is already high in cigarette smokers, compared with those who never light up. But what is about early morning smoking that makes that risk even higher?
The precise reason wasn’t investigated in the studies, but the researchers had a hypothesis: people who smoke earlier in the day may be more addicted. “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 lead researcher Dr. Joshua Muscat of the Penn State College of Medicine in a statement.
Early morning smokers may also smoke differently, suggests a researcher to the BBC. “Smokers who light up soon after waking tend to smoke each cigarette more intensively. So the most likely explanation of this finding is that the sooner a smoker lights up, the more smoke is taken into the lungs, and the higher the level of exposure to cancer causing chemicals,” said Cancer Research UK’s Professor Robert West, who was not involved in the study.
The takeaway, of course, is that smokers should quit. But the findings suggest that early morning smokers may be particularly vulnerable to cancer, and that they should be specially targeted by smoking-cessation programs.
“Smokers who smoke soon after waking may require special efforts to make them aware of their increased risk and the need for smoking cessation therapies,” wrote the researchers.