Nicotine by-product lingers in bodies of menthol smokers
Taste may not be the only difference between menthol and normal cigarettes.
Researchers in America have carried out a small study to find out how long cotinine, a chemical by-product of nicotine, stays in the blood of women, and tried to determine why. They found that cotinine stayed longer in women who smoked menthol cigarettes, compared with those who smoked other brands.
32 women participated in the study, 16 were black, and 16 were white. They all smoked at least five cigarettes a day. During the first day of the study the women smoked as usual, and the researchers measured the cotinine levels in their blood. For the next six days the women stayed at the research centre and did not smoke. In the meantime, the researchers recorded how long it took for the cotinine levels to diminish.
The researchers found that the rate cotinine vanished varied from woman to woman, but it stayed longer in women who were African American and smoked menthol cigarettes. They also found that cotinine tended to stay longer in women who had been alcohol drinkers for less time, and in those with a greater lean body mass.
Dr Ahijevych and colleagues said that they suspected it was the menthol cigarettes, and not racial factors that accounted for the difference, because there was no significant variation in how long cotinine remained in the blood of the different races.
In the US, African American women are more likely to smoke menthol cigarettes than white women. Only a third of the white women in the study smoked menthols compared with the majority of black women. Previous studies have found higher levels of cotinine in African American smokers, compared with white smokers.
Cotinine markers are used to determine if someone has stopped smoking. The new findings of this study may affect how the marker is used in smoking cessation programmes. Three women still had cotinine in their blood five days after their last cigarette, suggesting that it may take as long as a week after a person has stopped before it is clear that they have quit smoking.