Quitting smoking The health benefits of giving up smoking are enormous. It reduces the risk of lung cancer, other lung diseases, other cancers, heart disease and stroke. Within 10 to 15 years of giving up, an ex-smokers' risk of developing lung cancer is only slightly greater than someone who has never smoked. Quitting before the onset of serious disease increases healthy life expectancy. Despite the wealth of information available about the health benefits of quitting smoking, and the advice and support available for people trying to quit, it is still a very tough challenge for most smokers. One in four people in the UK smoke. For this reason, efforts are constantly being made to try to find more effective ways of helping people quit smoking. The aim of this programme is to look at whether using genetic information might be one way to do this.

How could genetics help smokers quit? Genetic testing Cigarette smoking Could genetic testing help people quit smoking in the future? London IDEAS smoking cessation programme Organisations to help smokers quit

Genetic testing

Most existing genetic tests are for diseases caused by a fault in a single gene, such as hereditary breast cancer. However, these rare forms of cancer only account for 5 to 10% of all cancers. There is therefore a lot of research going on into the genetics of other, common, types of cancer and heart disease, which are the two biggest killers in the UK.

Researchers are beginning to find genes that may make some people more likely to develop cancer and heart disease than others. An individual's risk of developing these conditions cannot be measured with genetic tests only. The odds also depend on, among other things, whether they smoke and what they eat. It has therefore been claimed that tests for these genes could help people to make more informed choices about their lifestyle, such as smoking, diet and exercise.

Cigarette smoking

Cigarette smoking is a major cause of premature death, and 1 in 4 adults in the UK currently smoke. More than 70% of smokers want to quit smoking, but each time they seriously attempt it, only 2 to 3% are successful.

Although smokers know about the general harms of smoking, and they say that health concerns are a reason when they try to quit, it is thought that they are optimistic that they personally will not develop health problems. For example, smokers tend to be sceptical about public health warnings and often doubt that messages about risk are relevant to them. Not surprisingly, it has been shown that people are more likely to act on health advice if it is made personally relevant to them.

In theory, information about a person's own genes, and how they affect their chances of developing tobacco-related cancers or heart disease, could be used to give personalised advice. This could increase the impact of the advice and help people commit to quitting.

Could genetic testing help people to quit smoking in the future?

Tests for smoking-disease genes are useful for research purposes, but it is important to stress that they are not available for clinical use at present. This means that you cannot get them from your doctor, clinic or pharmacist. The reason for this is that research into these genes is still ongoing, and it is not yet clear exactly how much of an effect these genes have on your risk of developing a smoking-related disease.

There is disagreement about exactly when such tests will be successfully developed for widespread use (will it be 5 years, 10 years, 50 years, or maybe even more?) but it is agreed that they will be available at some point in the future. It is therefore important that we understand what the psychological and behavioural consequences of such testing might be.

Very little is known about how people will respond to being given genetic information about their risk of developing smoking-related diseases such as lung cancer and heart disease. It may be that telling people that they have a higher than average genetic risk ("positive" test result) of some smoking-related diseases increases their motivation to quit, by making them realise they are doing harm to themselves personally. On the other hand, an individual who learns that they are at higher genetic risk than other people could simply feel anxious or even depressed, which could reduce their ability to quit. It could also lead people who receive a test result that indicates a lower than average risk ("negative" test result) to wrongly believe that it is ‘safe' for them to carry on smoking.

This issue is particularly important at the present time because some companies have already sold similar tests direct to the public, offering lifestyle advice on the basis of the results.

In the UK, the Human Genetics Commission recently held a public consultation and wrote a report to the government on how these companies should be regulated. In the process of the consultation it became clear that very little is known about the impact that such testing might truly have on lifestyle. Our study should help us understand this better, and contribute to the national debate. (NB. For information specifically about over-the-counter genetic tests, follow this link).

Organisations to help smokers quit

Giving up smoking can be easy for some people, but it remains very hard for most. There are organisations that aim specifically to help smokers quit:

NHS: giving up smoking
Quit.org.uk
Cancer Research UK
No Smoking Day
Quitline 0800 002200