Genes Raise Addiction, Lung Cancer Risk

Not all smokers get lung cancer. And some people can quit more easily than others. Some of the reasons may be genetic, new research shows. The studies found different versions of genes that increase the risk of both lung cancer and smoking addiction. Smokers who get the gene variants from one parent have a 30% greater risk of lung cancer. The risk goes up 80% for smokers who get the genes from both parents. Another study found that people with these genes get addicted more easily and smoke more. Three different studies found the variant genes on chromosome 15. USA Today and the Associated Press wrote about the studies April 3. They were published in the journals Nature and Nature Genetics.

What Is the Doctor's Reaction?

Non-smokers often wonder how smokers could ever continue to use cigarettes faced with the stack of serious health problems from tobacco. These new findings from genetic studies give us a peek at why quitting can be so hard.

Most research on the reasons for addiction has focused on the brain. It's well established that people differ in their tendency to become addicted to nicotine. This relates to variations in brain chemistry.

Three separate research teams have advanced our understanding of addiction beyond the brain. And it should be no surprise that it's in our genes.

The researchers found similar genes in people who smoke more cigarettes per day. In addition, these same genes are associated with less success at quitting.

Of course, it's likely that both the gene theory and the brain theory are correct. Our genetic makeup is going to have a major effect on how our brain functions.

What's important to remember is that beating any addiction is more than "just saying no." Addiction is not the product of bad character or weak moral fiber. The genes we were dealt and the way our brains respond to different substances affect our risk of being addicted.

I don't mean to imply that people addicted to nicotine or another substance have no personal responsibility for what they do. It's no different than people who have a greater genetic risk of becoming obese or developing heart disease. If you are genetically prone to any of these, you will need to act accordingly.

What Changes Can I Make Now?

If you have been unable to quit smoking, realizing that your nicotine addiction is not a weakness may help you take the necessary steps to stop. To overcome your genetic program and nicotine-craving brain chemistry, you will need help. Similar to other medical problems, it will take lifestyle change and usually medicine.

For some, nicotine replacement will be enough. But most people who have the nicotine genes will need more. Bupropion (Zyban, Wellbutrin) and varenicline (Chantix) are two of the most commonly prescribed medicines.

Here are some tips to help you along the way:

• Set a target date for quitting. Try to choose a time when you don't expect to be under a lot of stress.

• Make sure everyone knows about your quit date. Friends and family can help you stick to your goal.

• Before quitting, identify some activities that make you feel good, healthy and energetic. Plan to engage in them during the first few weeks of quitting. You will need to be distracted and rewarded during this time.

• When you feel the urge to smoke, replace it with several deep, slow breaths. Follow this with a drink of water. You may need to do this frequently during the first week or two.

• Recognize that withdrawal symptoms are temporary. They usually last only one to two weeks. Hang in there long enough for things to get easier.

• Be aware that the first week will be tough. Your body is still dependent on nicotine and the withdrawal symptoms are strongest.

• If you slip and have a cigarette, make a decision to quit again immediately.

• Start an exercise program. More people who exercise experience success than those who do not. This will help you avoid gaining weight and will improve your energy level.

What Can I Expect Looking to the Future?

These exciting genetic discoveries won't immediately offer new treatment options. But markers like these, once better established, will lead to better methods for treating nicotine and other addictions.

Copyright Harvard Health Publications - 2008