Key gene affects ability to quit smoking
People who process nicotine faster more likely to have difficulty kicking the habit
Quitting smoking is far harder for some people than others — and it turns out that your own personal genetics play a large role in determining success, both in quitting cold turkey, but also in finding the best therapies to support smoking cessation.
In the future, a simple genetic test will help you find the most effective treatment, but for now, it’s worth trying different approaches until you succeed.
The more scientists know about the genes that make up our personal blueprint, the more we can tailor prevention strategies and treatments to individual patients.
This is most famously true with diseases like cancer. But as we learn more about our genes, we’re able to use the information for a wider variety of health conditions.
As a scientist studying addictions, I’m very encouraged by the amount we’re learning about the genetics of tobacco addiction.
Just last year, we and others showed that genetic factors influ- ence who can stop smoking cold turkey, and also which treatments will be most effective in helping you to quit.
A key gene, CYP2A6, helps determine how quickly our bodies process nicotine.
About 25 to 40 per cent of us are slow to get rid of the nicotine from their systems and so have an easier time overall: they smoke less and inhale less deeply.
They’re most likely to be able to quit cold turkey and they also respond well to behavioural counsel- ling and the nicotine patch.
People who process nicotine faster struggle harder to give up smoking. Unfortunately, that’s the majority of us at 60 to 75 per cent. Recently, when researchers showed these “fast nicotine processors” photos of people smoking, to test Pavlovian responses, and took pictures of their brains, they had more intense reactions than the slow processors did — suggesting that, as these smokers try to quit, they’ll face greater temptation in their daily lives. This group also has a much harder time quitting cold turkey, but when they manage to give it up, the benefits are huge.
For example when using varenicline (Champix/Chantex) to help stop smoking, they show greater improvements in their anxiety levels, irritability and focus. For fast processers, varenicline works better than the patch.
When we scanned the brains of smokers, my colleagues and I found that the fast processers showed more activity between parts of the brain involved with addiction; there were no differences in non-smokers — indicating you had to be both predisposed (a fast metabolizer by genetics) and a smoker.
These brain changes help to underscore the importance of our genetic makeup in determining how the brain adapts to addictive drugs.
That’s why knowing whether you’re a fast or a slow nicotine processer will help you and your health provider to come up with the best treatment plan.
While still in relatively early stages, both a genetic test and a biomarker test should be commercially available in the future to help guide treatment choices.
I also hope that the more we learn about genetics and smoking, the more this knowledge will remove the frustration and stigma that many smokers feel when they aren’t able to quit, even though other people are successful.
If you’ve been unable to quit, it’s important to realize you are not “weak” — the playing field is not level.
Scientists estimate that genetics account for 60 to 70 per cent of our ability to stop smoking.
There may well be genetic forces that make quitting much tougher for you — so be understanding with yourself and try different methods to quit as the consequences of continued smoking are also worse for fast processors.
In the meantime, scientists will continue to make new discoveries.
The more we understand about our own bodies’ reaction to addictive drugs, the more successful we’ll be at tailoring prevention and currently available treatments and creating new treatments.
If you have been unable to quit, it’s important to realize you are not “weak” — the playing field is not level
Knowing whether you’re a fast or slow nicotine processer will help you and your health provider come up with the best treatment plan.