A team of scientists at Cambridge University has updated studies published by Cochrane in 2010 focusing on the interest of genetic tests in reducing risk-related behaviour.
Over the last few years, genetic tests available over-the-counter in some countries (Canada, United Kingdom and Finland, etc.) “have allowed individuals to obtain their genetic risk profiles for a certain number of diseases”. The results are delivered directly to the “consumer”, bypassing a doctor.
These tests may “be of some interest if they can reduce the risk of developing the disease in question by inciting individuals to modify certain types of behaviour”: smoking cessation, increasing the amount of exercise or dietary measures, for instance. However, after analysing 18 studies comparing the behaviour of “subjects with a personalised estimate of their genetic risk regarding a number of diseases which could potentially be modified by changing certain types of behaviour”and that of untested subjects, scientists noted that the declaration of a genetic risk has “no effect” on smoking cessation, physical activity or even on alcohol abuse, medication, protection against UV rays or following screening programs. However, they have “not noticed any negative effects such as depression or anxiety following the announcement of a risk”.
The authors conclude that “these genetic tests which are accessible to some people do not appear to be of any interest in reducing risk-related behaviour”. They nevertheless suggest that “the way in which the results are delivered could be relevant”. The announcement of a risk could have greater impact “if it were used to support information provided by a health professional”.