The difficulty of quitting smoking depends on people’s genes. Scientists discover that the DNA sequence Taq1A influence people’s smoking habits.

The study, published online on Dec. 1 in Translational Psychiatry, studied 11, 075 people including 9,487 Caucasians, whom the genes are significantly associated with smoking cessation. Experts realised that having the A2/A2 variant of Taq1A made quitting easier. Experts suggest that this regulates concentrations of synaptic dopamine. Dopamine is a neurotransmitter that helps control the brain's reward and pleasure centres. However, the study only shows the association of the gene with success of quitting smoking instead of actually proving it.

“This variant has been studied for years, but this study provided more convincing evidence on the role of this genetic variant in smoking cessation by analyzing a significant large number of smoke samples,” said study co-author Ming Li, Health Magazine reported. Her team claims that more research into genetics and efforts to quit smoking must be conducted. This will help pave the way for the development of better treatments that target the smoker’s genetic predispositions.

Cancer Council Australia states that quitting smoking is one of the most important things anyone can do to reduce the risk of cancer. Tobacco smoke contains more than 70 carcinogens. The organisation says that once a person quits, almost all nicotine is out of the system within 12 hours after stopping. After one year, the risk of heart disease drops and the risk of lung cancer is halved 10 years after quitting.

“The next step, in terms of advancing the science of smoking cessation, is trying to figure out exactly what the gene does, what proteins it codes for, and to see if there’s some way to modify the way it works,” said Norman Edelman, senior medical consultant for the American Lung Association. “The more you know about smoking and the predilection to smoke and smoking cessation, the more you are going to be able to develop effective strategies to help patients.”

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