Smokers who light up first thing after waking up are more likely to develop lung cancer than those who wait at least an hour before taking their first puff, reports the Daily Mail.
So says a study published in the journal Cancer. Researchers found that the level of nicotine was higher with the first cigarette, perhaps because smokers inhaled more intensely.
They analyzed 4,775 cases of lung cancer and 2,835 controls, all regular smokers. Those who smoked 31 to 60 minutes after waking were 1.31 times more likely to develop lung cancer than those who waited more than an hour.
Those who lit a cigarette within 30 minutes after awakening were 1.79 times greater risk of developing the disease.
"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 study researcher Joshua Muscat at Penn State College of Medicine.
As for cancers of the head and neck, the ratios were 1.42 times higher if you smoked a cigarette within 31 to 60 minutes after waking. For those who smoked less than 30 minutes after getting up, the odds were 1.59 times higher.