Smoking Gene

Genetics may someday help smokers decide the best way to quit.

May 7, 2008
Is the key to quitting in our DNA? [Photos: Juergen Jester, Rodolfo Clix. Compiled by Karina Hamalainen]
Is the key to quitting in our DNA? [Photos: Juergen Jester, Rodolfo Clix. Compiled by Karina Hamalainen]

** Editor’s Note: The staff of Scienceline is taking a short break to work on future stories. In the meantime, we will repost some of the site’s most popular articles from the last six months. We will return to publishing new content on May 19. This article originally appeared March 5. 

There are a lot of ways to quit smoking: patches, gums, lozenges, inhalers, prescription pills, self-help books and many more. The proliferation of these products illustrates the simple truth that it’s very tough to quit. Smokers rarely succeed on their first try, and fewer than one-third are ever able to give up cigarettes using these available methods.

With such a low success rate, how would a smoker know which one would work the best? The answer might be in their genes.

Bupropion (marketed under the name Zyban), a popular drug prescribed to help patients quit smoking, has been shown to be more effective in people that possess certain “smoking genes,” according to a study published late last year in the journal Biological Psychiatry.

“We believe [the results] are an exciting step forward in seeking information about how one responds well to which drugs – the holy grail of personalized medicine,” said Rachel Tyndale, author of the study and professor at the University of Toronto.

These results suggest that by using genetic testing at the outset, patients can bypass some of the early false starts of smoking cessation. If they have the right genetic variant, then they know that bupropion works well for them and can tailor their treatment plan accordingly. Patients can opt for the drug before buying nicotine replacement gum or pursuing counseling options.

Tyndale’s team chose to look at the gene CYP2B6, which is associated with the body’s ability to process nicotine. They recruited 326 moderate-to-heavy smokers who smoked half a pack a day or more. The participants were divided into two groups: one that was given the standard two-month course of bupropion and another that received a placebo. The researchers monitored their progress over a six-month period.

About half of the smokers in the buproprion group had a variant of the gene CYP2B6 that made them almost three times more likely to be able to quit smoking using bupropion when compared with the placebo group. After six months, those with the smoking gene were still much more likely to have avoided cigarettes.

Smoking cessation expert Douglas Jorenby, director of clinical services at the University of Wisconsin Center for Tobacco Research and Intervention in Madison, agrees that “a major goal now… is to connect [the patients] with the correct treatment.”

While this development is a step forward, Jorenby would like to see the experiment replicated in order to verify the results.

Jorenby also had concerns that genetic testing is not yet cost-effective. Currently, the kind of genetic testing needed for this study is not commercially available, and it will be expensive when it does eventually enter the marketplace. For comparison, it costs around $2,000 to test for the breast cancer genes.

While this initial study shows hope for everyone struggling with smoking addiction, there is still a lot more to be done before its lessons can be implemented. In the meantime, Tyndale’s group is gearing up to repeat their study on this smoking gene.

Related on Scienceline:

Is there a genetic fingerprint for loneliness?

The HapMap project is using genetics to diagnose rare diseases.

About the Author



Michael Thompson says:

How long has “smoking” been a practice? 3,000 or 4,000 years at most. How long have hominids been here? 6 million or 7 million years. How could a “smoking” gene have evolved in 4,000 years? Could someone explain this?

Susan says:

While many of us are shunned by society for not quitting, the tobacco co.s get more money for cigarettes. Why aren’t THEY forced to ween down the amount of nicotine put into cigs say, over 20 years until finally cigarettes are no longer addictive? Why can’t we finally go directly to the source of the problem instead of millions of individuals?

Brent says:


If someone is truly addicted don’t you think that they would smoke more if the amount of nicotine is decreased? The addiction is to nicotine not the cigarette. So even if the amount is reduced, the need would still be there and more would be smoked and hence more would be bought. – Sort of the opposite of what needs to happen.

PATTY says:

I tend to agree with Susan’s comment (4/4/08)..why can’t tabacco companies reduece the amount of nicotine?? Wouldn’t that help us all??

Jimmy says:

I have smoked for 3 years and I agree with Brents comment.

Marie says:

I agree with Brent. I have smoked for about 5 years now and I know that if the companies started reducing the amounts of nicotine in their cigarettes, I’d start smoking more. Cigarettes just got more expensive and the last thing I really need is to be smoking more b/c of reduced amounts of nicotine.

Bobbye Davis says:

Susan and Patty are correct. The cigarette co.s have increased the amout of nicotine by a substantial amount in just the last few years in order to make sure they keep their current customers. There could be no other reason to do so. Now there are studies to show that nicotine, not just the carcinogens in the smoke can cause cancer. If they were truly trying to provide ways for people to quit, as they have promised and have claimed to do, THEY WOULD NOT INCREASE NICOTINE, BUT DECREASE IT instead. SMOKING WOULD Be PLEASURABLE IF IT WERE LESS ADDICTIVE AND DID NOT MAKE YOU FEEL SO BAD. THEY ARE OUT TO KILL PEOPLE IN ORDER TO MAKE MONEY. NOTHING HAS CHANGED WITH THEM. THEY NEED TO BE REGULATED AND PREVENTED FROM INCREASING THE AMOUNT OF NICOTINE THEY ARE PUTTING IN CIGARETTES.

Bobbye Davis says:

Quitting smoking is all about weening yourself off of nicotine, getting it out of your system. Increasing nicotine in cigarettes is never a good thing, now is it really? If you really want to quit, that is what you are doing, not increasing the nicotine. That is exactly why the patches and gum didn’t work for me, because I could never get rid of the nicotine. Gradually quiting by decreasing the amount of nicotine or going cold turkey is the only way to quit, including any other help you can get, but never increasing the amount of nicotine. Now really!

Leah says:

I have been smoking since I was 17 years old, back,then cigarettes were so easily accessible to purchase. Now I am 46 years old, and all of a sudden there is this big crisis all over the country about where one can smoke (if at all in some places). How bad it is for our health,etc. Did the big tobacco companies ever stop to consider how addictive smoking is back then! Of course not it was the hip thing to do, advertisement’s everywhere, from newspapers to billboards. Let’s get real here, andto further the matter what ever happened to our freedom in this country! Maybe the law should start going after the drunks on the highway, and drug addict’s behind the wheel of a car. Seems to me there are a lot more innocent people killed in this country by these idiot’s than someone who is simply trying to have a simple cigarette somewhere without having to feel like some sort of a threat to society. Give me a break, afterall when I started smoking all those years ago no one told me how addictive my chosen habit would become!!!!!!

Connie Siler says:

I smoked 2-3 packs of cigarettes for 35 years. I gave up smoking and started chewing nicorette gum almost 3 years ago. I started with about 8-10 4mg pieces of gum a day, and it has gradually increased to 20-24 4mg pieces of gum per day. The nicotine in the gum is very addictive. The more you chew, the more your body craves. I am smoke free, but the addiction is still there.

Michelle says:

The first thing I had to learn before I quit smoking it that it is no one elses fault that I was addicted to cigarettes (not even the tobacco companies) and it’s not their responsibility to help me quit. The next thing I did was go to my Dr. and get a prescription for Chantix and I have’nt had a cigarette in almost 3 weeks. The great thing about Chantix is that it’s NOT a NRT, there is no nicotine in it at all and cravings are minimal.

Jeremy says:

I have smoked since I was 9 years old, that is except for about a year and a half. I am 34 years old now. I believe what the cigarette companies should be charged with murder in each case of death directly related to their products, and I believe they should be shut down all across the globe. Talk about mass genocide! I am addicted to the garbage they put into cigarettes, the nicotine, the act of smoking, and the whole shebang… I never want to die of cancer, and until now I have not gotten cancer. There must be a way developed to halt my addiction. I will tell you this… if there isn’t, I will die a smoker. I am aware that there is no way that I have tried to quit that will work. I wake up, and I smoke. All day, every day I smoke. I know that cigarettes are harder to quit than heroine, and I have one lit here beside me. I just to a “drag” and I feel worse allready. The body will keep me smoking one cigatette, after another, until it is satisfied with the nicotine level it needs to function. It doesn’t matter what brand, “lights” or “regulars”, “king sized” or “100’s”, or if I smoke the whole cigarette or not. The body craves and will crave until it is satisfied. I recently moved back to Texas to be able to smoke freely in my own home when I was not allowed to smoke any longer where I was living. Now I cannot smoke at bars with a glass of beer. I once saw a place that I need to mention. I was at a hospital, and I needed a cigarette. I found a place where people with cancer were allowed to smoke. It was called a “Smoker’s Haven”. I left my cigaretts there and tried to quit that day. It did not work… I wish the best for you all. I have tried and tried. At all costs to the companies, you should sue them and push for criminal procecution.

jaehyo says:

dont smoke if you dont want to be addicted…smoking can be addictive and its true

Michael says:

Could a scientist address my question (the first comment here)? Plus, answer this: The gene is associated with nicotine. Is nicotine a naturally occurring substance in the body even among people who have never smoked?

Matt O says:

All right, I’ve been smoking for about a year, I love smoking honestly, I know it’s terrible for me, sure, but that was my decision to start, all the tobacco companies are doing is making money, it’s called a free economy, let people make money how they know how to, it’s not their fault people started smoking, it’s the persons, they shouldn’t be required by an law saying it’s bad to put X amount of nicotine in their cigarettes, and I agree, if there was less nicotine I’d buy more, definitely, what we should be worried about are the prices of oil, in today’s world we have to drive cars, there’s barely a choice in that unless you live in a major city where your destination is in walking distance, we shouldn’t be worrying about other people’s business and personal bad habits, we need to concentrate on the big picture, and leave the smokers alone.

Matt O says:

oh, and one more thing, stop blaming others for your problems. If you’re a fatty, don’t blame McDonald’s blame yourself, there’s no one making you eat there, and if you have cancer or problems from smoking, that was your choice too, I’m sorry you’re sick, and I wish there were a cure, but there’s no one to blame but yourself, people need to start taking responsibility for their actions instead of blaming a major company and trying to make a quick buck. Thanks

Barb says:

I have smoked for 50 years, my father died of lung cancer, my mother of pancreas cancer both attributed to cigarette smoking, yet I still smoked. Up to 3 packs a day, I would light one smoke a little put it out and light another. I tried all the patches, they don’t work because you are putting nicotine in your body yet, I tried chantix and it worked , I have been smoke free sing 5/3/2007, but I constantly want to smoke its not the nicotine but the psychological addiction that is so strong for me, that sometimes I cry and dream of smoking, I have no nicotine in my bloodstream for almost 1 year, buet its still hard.

Katherine says:

I would just like to say that I have been a smoker for many years. I dont understand how there can be a smokers gene. Smoking is a learned behavior, Much like shooting up heroine. To tell people that they are genetically predisposed to smoke is irresponsible. Yes you can say that a person has an addictive personality . The truth is nicotine is a drug not unlike heroine and people all over the world are addicted to it. The truth is the worlds biggest drug epedemic is not illegal drugs but legal drugs such as nicotine, and the drugs that Drs. freely pour over their patients.

Good luck to all that are trying to quit. And please remember that the ones that cant are nicotine addicts and have really no control over their addiction.

Katherine from Canada

max says:

bucket of chicken two liter soda five biscuit eating people. make your own choose.

Ann says:

I’ve smoked for 54 years, no info on what it would do when I started. Stopped smoking a year ago with Chantix. It all boils down to taking responsibility for your own life, habits, addictions & all included. Will power, self-denial or what ever you want to call it–I’m not now blaming anyone or anything–either you want to quit or not & all help is appreciated. What works for one person won’t necessarily work for another === Good luck to you all!!

Teri says:

After reading all of the listed comments, I find it interesting that not one person actually talks about addiction. Addiction and the possibility of it being genetically passed on has already been proven. Nicotine is an addictive drug. Period. If you are gentically predispositioned for addiction your chances of becoming addicted to anything, wheather it be the nicotine in cigerettes, drugs, and / or alcohol are much greater than someone who is not. When a drug is introduced into someones system and the addiction is started, the body natural starts to build a tolerance and the need becomes greater and greater, thus the drug addict always looking for more and more. Nicotine is no different, it is a drug. The only reason cigerette companies increased the amount of nicotine in cigerettes was to increase the probability of new users becoming addicted. Increasing it would only slow do the amount purchased by those addicted, for a time then it would stabilze again. And decreasing nicotine would only increase their profits and would make more sence, as the addicted smoker would smoke more thus purchase more. I truly think the reason they have taken this approach is because most addicted smokers are older and remember the time of nuc cheaper cigerettes, thus it is quit or keep it in reason due to budget restraint and the much higher increase in the cost of cigerettes. (This is the norm, there will always be the hardcore smokers that will smoke no matter the cost (finicially or phyiscially), but they would not be able to substain the Large Tabacco companys in there high profit levels. Since the increase in anti-smoking laws the average number of regular smokers has decreased. So the cigerette companies are searching for new ways to bring in new (which would be younger) smokers. The increase is the only answer for them. And yes I am a 30 year smoker. I have tried numerous times to quit. It was easier for me to quit all the other drugs, I was addicted to in the past. Yet, the nicotine in cigerettes is the hardest and the one I still am struggling to over come. Yes, I truly believe this addiction has a genetic basis. I am not quite sure the Scientific community is even asking this question or spending research dollars on this, when it is only common sense to see that addiction is addiction is addiction. Nicotine is a drug, a drug that a proven to be extremely addictive. So go back and reread the research already achieved with drug addiction period and the genetic possiblities. That has already be researched. So take the money your are wasting on this and any future studies and sent it in much better way. How about a way to quit with a lot better results. Has the gentic question has not really help the the treatment of addicts, other then if you know you have it, STAY AWAY FROM, if you don’t start you don’t have to worry. So parents they have dealt with addiction in their lives should know they have passed that possiblity to their children and should work everyday to educate their children and keep them from even tring the first one. The only was to cure any addiction is prevention. I also feel that Tabacco Companies need to be force to do more in preventing or not be allowed to continue in inventing ways to get that new smoker (they need) addicted. But we all know that money talks.

Mary says:

I started smoking when I was 12. I had to be cool, I wanted to impress my friends, I thought I looked mature. We all know that wonderful saying.. if I only knew then what I know now… I am now 47. Smoking almost two packs of cigarettes a day (just lit one up)and I hate it, I hate it with a passion. Can I quit?… No…. I have tried gum, patches,pills,hypnosis, gonig to classes and going cold turkey, you name it I tried it. It is hard! Someone mentioned lowering the nicotine in cigarettes over a period of twenty years. Sounds good, but by then I would be close to death of old age anyway. For me, yes I am addicted to the nicotine of course, but also addicted to lighting the cigarette, holding the cigarette, puffing on the cigarette, exhaling the smoke, sitting at my computer and drinking my tea with a cigarette going. lighting up after having an argument with somebody or after getting bad news,,, yes it calms me down.(give me a break!)Being in my own little world that nobody can get into when I am smoking a cigarette. Just sitting here typing these words make me sick to my stomach yet I am here with my cigarette going. My family begs me to quit and I tell them I will one day, hopefully soon. I think I agree with lowering the nicotine in the tobbaco just as there are regular, lights, and ultra lights there could be reduced amounts of nicotine in different cigarettes, not like the awful tasting cigarettes they came out with a few years ago, the ones that tasted like smoking a metal pipe. For me I wonder if they came up with cigarettes like this along with the use of some type of medication, gum, patch, pill would that help? A hardcore smoker does not care about the high tax that you put on a pack of cigarettes or banning them from smoking in public places or anything like that. I had heard about the person that had a stroke and the stroke affected the specific part of the brain that deals with addiction. Supposedly that person was a smoker before the stroke yet did not remember being a smoker after the stroke. I wonder how much progress the scientists have made on that? Ok I am starting to mumble here. Best of luck to anyone who is trying to quit and for those that are thinking about trying the taste of a cigarette…. PLEASE DON’T!

Doug says:

I smoked, then I used Skoal. Because of a medical treatment I was prescribed Bupropion, this was about a year ago. My Doctor told me this could be a medication to use to quit using tobacco. It took me about a year or so and 2 boxes of Nicorettes and I am tobacco free. I smoked,I quit, It was MY habit. The medication really helped in my opinion. But, it was my decision to quit. If you are trying to quit, don’t give up, because you can do it.

jeanne sutton says:

karina — i’m writing this from your house. just read your article on your mother’s machine, and i’m impressed. zyban worked for me, the first time i quit for a length of time — that was in ’97. i went back, though — once an addict, always an addict — when it comes to nicotine. didn’t use anything this past july 30, when i quit again. and haven’t had one since. it’s like being addicted to alcohol — no ‘cure’ but there is a treatment — don’t take the first puff.
question: is anything being done relative to the genetic connection in the research or followups around chantrix? all best!

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