WASHINGTON - Nicotine builds up gradually in smokers’ brains rather than spiking after each puff, according to a study that might help point to new ways to help people quit smoking.
Dr. Jed E. Rose of Duke University reports in the online edition of Proceedings of the National Academy of Sciences that nicotine buildup in the brain is gradual over several minutes. Scientists have theorized there is a spike of nicotine about seven seconds after each puff, but almost no measurements had been taken until now, Rose said.
“We were surprised to find that the rate of uptake was much different from what one commonly hears,’’ said Rose, who directs the Duke Center for Nicotine and Smoking Cessation Research.
Rose used brain scans to measure the nicotine levels in 13 regular smokers and in 10 people who smoke occasionally, an indication they were not addicted to nicotine.
Maximum brain levels of nicotine were reached in 3 to 5 minutes, and built up more slowly in the addicted smokers, the researchers found.
“This slower rate resulted from nicotine staying longer in the lungs of dependent smokers, which may be a result of the chronic effects of smoke on the lungs,’’ Rose suggested.
“Now that we know there are not these spikes’’ that had been expected, Rose said, researchers may be better able to help smokers get what they need from cigarettes, but in a way that’s not addictive.
Still in question: Why do some people become addicted to cigarettes and others don’t? The difference in the rate of nicotine buildup in the brain does not explain this, the researchers said.
The research was funded by the tobacco companies Philip Morris USA and Philip Morris International. The researchers said the companies had no role in designing or carrying out the research or in analyzing the results.