London - Telling someone they have a high risk of developing cancer or Alzheimer’s does little or nothing to change their lifestyle, research suggests.
While genetic testing is one of the fastest moving aspects of medical research, with scientists now able to tell us with a simple blood test whether we are likely to develop heart disease, lose our memory or fall victim to cancer, we tend to ignore such warnings.
Doctors have assumed until now that people given information about health risks will take steps to reduce them – for example, by stop smoking, changing their diet or taking up exercise. But new research led by Cambridge University revealed that people actually tend to accept their fate.
Communicating the results of genetic tests has “little or no impact” on behaviour or lifestyle, the researchers found. The team, whose work is published in the British Medical Journal, analysed 18 previous academic studies involving more than 6 000 cases.
They found that people told they were at risk of skin cancer, for example, did not avoid the sun. They were no more likely to enrol in health screening programmes, and ignored health professionals’ advice about diet, keeping fit and smoking.
The teamcalled for a rethink of the use of genetic testing. Genome sequencing – reading someone’s entire DNA – has opened up the potential to tell individuals whether they carry genes known to increase their risk of disease.
Critics say just because someone carries a particular gene for a disease does not mean they will definitely develop the illness.
But others argue that if someone knows they have a greater risk of getting a disease, they can make informed decisions what to do about it. In extreme cases, women with the faulty BRCA cancer gene, famously carried by actress Angelina Jolie, sometimes choose to have their breasts and ovaries removed to reduce the risk of cancer.
In more common examples, people whose DNA means they are more susceptible to heart disease are encouraged to take up exercise and cut down on drinking.
But study leader Professor Theresa Marteau, director of the Behaviour and Health Research Unit at Cambridge, said: “Expectations have been high that giving people information about their genetic risk will empower them to change their behaviour but we have found no evidence that this is the case.”
Daily Mail