Could There Be a Quit-Smoking Gene

Could There Be a 'Quit-Smoking' Gene? Study suggests willpower isn't the only player
WebMD News from HealthDay

By Alan Mozes

HealthDay Reporter

THURSDAY, Dec. 3, 2015 (HealthDay News) -- Some smokers have much more difficulty kicking the habit than others. Now, a new review of prior research identifies a potential culprit: genes.

Researchers analyzed genetic differences cited in 22 studies involving nearly 9,500 white smokers. Of particular interest were variations in genes involved in processing dopamine, a neurotransmitter that helps to regulate the brain's reward and pleasure centers.

Experts believe that the nicotine found in tobacco boosts dopamine in the brain, leading to addiction.

The researchers wondered if variants in genes that regulate dopamine might be associated with the ability to put out the butts for good.

In the end, the scientists focused on a DNA sequence called Taq1A. They found that smokers who carried a variation of that sequence -- called A2/A2 -- appeared to have an easier time quitting smoking than those who carried other variations of the Taq1A sequence.

"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, a professor in the department of psychiatry and neurobehavioral sciences at the University of Virginia.

The findings were published Dec. 1 online in Translational Psychiatry.

Li, working with researchers from Zhejiang University School of Medicine in Hangzhou, China, noted that roughly 6 million people die worldwide every year because of smoking.

The studies included in the current analysis were conducted between 1994 and 2014, and numbered from fewer than 100 participants to more than 2,000.

Quitting success varied widely, ranging from less than 10 percent to nearly 67 percent, the researchers reported.

Ultimately, the team found there was a "significant association" -- but no definitive proof -- between having the A2/A2 DNA variant and an increased ability to successfully quit.

The authors said the finding should encourage more research into the genetics behind efforts to quit smoking. Such research could eventually lead to the development of personalized treatments that target each smoker's inherited predispositions, they suggested.

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