Technology & Science

Nicotine gene linked to addiction

Whether smoking your first cigarette brings on a pleasurable buzz or a wave of nausea may depend on what type of nicotine-related gene you have.

Whether smoking your first cigarette brings on a pleasurable buzz or a wave of nausea may depend on what type of nicotine-related gene you have.

Smokers who had one form of a nicotine-receptor gene were eight times as likely to report that their first cigarette gave them a pleasurable buzz, researchers said in Friday's online issue of the journal Addiction.

American researchers studied data from 435 volunteers to probe the link between forms of a nicotine-receptor gene called CHRNA5, how people recalled their first smoking experience, and how they smoke now.

They compared three groups: those who never smoked; those who never got hooked after trying at least one cigarette but not more than 100; and regular smokers who lit up at least five cigarettes a day for at least five years.

Regular smokers were far more likely to have the less common form of the gene compared with those who never smoked, the researchers said.

"It appears that for people who have a certain genetic makeup, the initial physical reaction to smoking can play a significant role in determining what happens next," said Ovide Pomerleau, the study's senior author and a professor of psychiatry at the University of Michigan Medical School.

In part, the findings may explain why some people get addicted and face a higher risk of developing lung cancer, he said.

The role of other genes, social pressures and environmental factors need to be explored.

Some of the study's authors serve on advisory boards for nicotine treatments, or hold a patent on the gene variant.

In a related study on Tuesday, Canadian researchers reported they were able to control whether the first exposure to nicotine was enjoyable or repulsive by manipulating receptors in the brains of rats.

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