Genes cause smoking addiction

A common genetic variation that increases a person’s susceptibility to nicotine addiction, as well as increasing their risk of lung cancer and arterial disease, has been identified in a major international study involving University of Otago researchers.

Dr Greg Jones, of the Otago Vascular Research Group, says the study, just published in the prestigious journal Nature, found the genetic variation or genotype was far more common amongst heavy smokers.

Dr Jones says receptors in the brain and blood vessels that are activated by nicotine appear to be more active in the people with this genetic variation. Consequently they have a greater tendency to become addicted to smoking.

"Inheriting this one factor means they face a double whammy. Not only are they more likely to be heavier smokers but their risk of lung cancer increases by 18 per cent and their risk of arterial disease goes up by 10 per cent.

"It is an example of a situation where nature influences nurture – where genetics and environment overlap."

Dr Jones says the Vascular Research Group supplied information from close to 1000 case and control subjects from the Otago/Southland region to be part of the statistically powerful study.

The international study covered seven different countries using information gathered from 3700 people with either lung cancer or arterial disease and a further 30 000 disease free control subjects.

"The bottom line is that regardless of whether you have the genetic variation or not, you should not smoke," says Dr Jones.

"Either way, smoking remains a huge risk factor for cardiovascular and lung disease."

(Source: Nature: University of Otago: April 2008)