A new study suggests young people are more likely to become addicted to cigarettes if they carry a specific form of a gene that helps clear nicotine out of the liver.
Those with the inactive form of the CYP2A6 gene were about three-times more likely to get hooked on the habit than those with the normal form. The study authors say the interesting thing is they were also less likely to smoke as many cigarettes. In a study, carried out among seventh graders in 10 schools, kids with the normal gene averaged about 29 cigarettes a week, compared to just 12 for kids with the inactive form of the gene. Kids with a partially inactive version of the gene smoked about 17 cigarettes a week.
Researchers believe the inactive gene causes nicotine to stay in the body longer, thus requiring people to smoke fewer cigarettes in order to satisfy their cravings. But this slower clearance also boosts brain exposure to nicotine, leading to a greater chance of becoming addicted.