Genetics and tailor-made diets: Some ethical issues

This paper has two aims. The first aim is to seek to clear up a significant confusion in some recent discussions about the role of genetics in tailor-made diets. This confusion relates to the difference between screening and testing for genetic traits related to dietary factors. Screening involves large-scale interventions in an asymptomatic population. Testing involves a focus on particular individuals chosen because of family history, medical symptoms, particular lifestyle etc. This paper explores this distinction and illustrates its importance in the area of genetic/ food interactions. It is argued that this distinction makes a significant difference to the ethical arguments about such interventions. Screening is far less likely to occur, at least partly because of the ethical problems, so discussion should focus largely on testing. The second aim is to outline and critically review the different ethical arguments that might be advanced about the use of genetic testing related to tailor-made diets. Once again it is suggested that we need to take care to specify what we wish to discuss. For example, both the particular type of test and the nature of the genetic trait we are thinking about will make a difference to the ethical acceptability of the testing. It is concluded that we need to be more precise in what we mean when we construct our ethical arguments about tailor-made diets.