Genetics make people more likely to get addicted

Published on April 25, 2008 2:37 AM

Scientists have identified that some people can light up now and then without getting hooked, while others are addicted from their first whiffs. After a full research they showed that the smoking addiction depends on genes.

Scientists have identified genetic variations that appear to make people more likely to get hooked on cigarettes and more predisposed to lung cancer.

The antismoking researchers make the strongest case of nicotine addiction and sheds light on how genetics and lifestyle join to cause cancer.

"This is kind of a double whammy gene. It also makes you more likely to be dependent on smoking and less likely to quit smoking," said Christopher Amos, professor of epidemiology at the M.D. Anderson Cancer Center in Houston.

A group of researchers reported that a smoker who inherits these genetic variations from both parents has an 80% greater chance of lung cancer than a smoker without the variants. The researchers disagreed that the risk of lung cancer are caused by how often a smoker fumes.

The scientists studied the genes of more than 35,000 white people of European descent in Europe, Canada and the United States.

Even after this research they aren't quite sure if what they found is a set of variations in one gene or in three closely connected genes. But they are convinced that the gene variations govern nicotine receptors on cells.

"This is really telling us that the vulnerability to smoking and how much you smoke is clearly biologically based," said Dr. Laura Bierut, a genetics and smoking expert.

Antismoking scholars understood that not everyone takes drugs for the same reason as not everyone smokes cigarettes for the same reasons.

People who have been found to have a genetic predisposition to addiction and lung cancer could find it harder to get health or life insurance.

Scientists’ findings are the following:

Smokers who get the set of variants from only one parent see a risk of lung cancer that is about one-third higher than that of people without the variants. They also smoke about one more cigarette a day on average. This group makes up about 45% of the population studied.

Smokers who inherit the variants from both parents have nearly a 1-in-4 chance of developing lung cancer. They smoke on average two extra cigarettes a day. This group accounts for about one in nine people of European descent.

Smokers who don't have the variants are still more than 10 times more likely to get lung cancer than nonsmokers.

Scientists hope that this research would help them to explain why some people can quit and others fail.