A team of Japanese scientists have unearthed a gene that explain why some people are heavy smoker. The definition of heavy smoker here is someone who lights up first thing in the morning. The definition of what is a smoker varies considerably, but essentially ”a smoker” is defined as someone who has smoked more than 100 (or sometimes 300) cigarettes in their life. A ”former smoker” is someone who has not smoked in two weeks or does not smoke regularly, but who has smoked more than 100 or 300 cigarettes in their lifetime.
The team at Osaka University found that among heavy smokers — defined as those who light up as soon as they get up in the morning — a gene responsible for producing an enzyme that breaks down nicotine is more active than others, the Nihon Keizai Shimbun reported.
After examining the gene CYP2A6 among 300 smokers and those who had smoked in the past, the scientists found that 70% of those with a highly active type of the gene were highly addicted to nicotine.
The percentage of heavy smokers among those with a less active CYP2A6 was lower at 40%, the finding showed.
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