Like all scientific innovations, nutrigenomics develops through a constant interplay with society. Normative assumptions, embedded in the way researchers formulate strands of nutrigenomics research, affect this interplay. These assumptions may influence norms and values on food and health in our society. To discuss the possible pros and cons of a society with nutrigenomics, we need to reflect ethically on assumptions rooted in nutrigenomics research. To begin with, we analysed a set of scientific journal articles and explicated three normative assumptions embedded in the present nutrigenomics research. First, values regarding food are exclusively explained in terms of disease prevention. Health is therefore a state preceding a sum of possible diseases. Second, it is assumed that health should be explained as an interaction between food and genes. Health is minimised to quantifiable health risks and disease prevention through food -gene interactions. The third assumption is that disease prevention by minimisation of risks is in the hands of the individual and that personal risks, revealed either through tests or belonging to a risk group, will play a large role in disease prevention. Together, these assumptions suggest that the good life (a life worth living, with the means to flourish and thrive) is equated with a healthy life. Our thesis is that these three normative assumptions of nutrigenomics may strengthen the concerns related to healthism, health anxiety, time frames and individual responsibilities for health. We reflect on these ethical issues by confronting them in a thought experiment with alternative, philosophical, views of the good life.

About a decade ago, scientists and science journalists presented nutrigenomics as a grand promise that each of us would soon know which foods fit in our personal healthy diet. Meanwhile, expectations have been adjusted to fit a changed reality. Simultaneously, societal issues surrounding personalized nutrition continue to rise, including whether consumers need it, food industry can produce it, all relevant stakeholders are willing and able to work together, and if it is a desirable way to go for nutrition. The commentary below reports the main results of 6 research projects that focused on nutrigenomics and its role in society.

Again and again utopian hopes are connected with the life sciences (no hunger, health for everyone; life without diseases, longevity), but simultaneously serious research shows uncertain, incoherent, and ambivalent results. It is unrealistic to expect that these uncertainties will disappear. We start by providing a not exhaustive list of five different types of uncertainties end-users of nutrigenomics have to cope with without being able to perceive them as risks and to subject them to risk-analysis. First, genes connected with the human body or nutrients can have different functions in interaction with their environment (for instance, one nutrient can be healthy for the heart, but can also be a high risk in relation to cancer). Secondly, uncertainties are formed by risk analyses. Will it be possible to calculate a certain risk of getting a certain condition with a certain lifestyle? Will it be difficult to separate the genetic component and the lifestyle component? How high will these risks be? How will these risks be handled by the actors? In the case of personal genotyping, it is unclear how frequent an adverse polymorphism will occur. Will every individual have a certain vulnerability to a certain disease or will it only be applicable to a small group of the population or particular populations? Thirdly, dietary advices are subject to uncertainties and still to be developed professional standards: some will have adverse outcomes, some will not delay the disease, and some will assume uncertain associations between nutrients, lifestyle, and genetic vulnerabilities. Fourth, with regard to the usefulness of tests it is uncertain to what extent risks indications about obesity and diabetes and other vulnerabilities really influence people to live healthier and therefore will help to prevent these conditions. Fifth, it is uncertain how and what nutrigenomics products will be developed and used. Will it be possible to develop more effectively health improving products? Or is this too difficult and will nutrigenomics continue to be used in not always justified health claims as a commercial and marketing tool?M. Korthals (&) Á R. Komduur Applied Philosophy, Wageningen University, Wageningen, The Netherlands e-mail: Michiel.korthals@wur.nl 123 J Agric Environ Ethics (2010) 23:435-454 DOI 10.1007 Present-day ethics and theories of responsibilities presuppose that uncertainties will disappear and concentrate on what seems to be fixed and stable in science. We develop provisional thoughts that assume that the dynamic of science to produce uncertainties and dilemmas is endemic, and we stress the need for consumers to institutionalize value searching, exploring, and deliberating devices in the health and food sector to find out the most important uncertainties and correspondingly socially desirable research priorities.

This study examines whether the assumptions embedded in nutrigenomics, especially the alleged relation between information about personal health risks and healthy behaviour, match how people account for the relation between food, health and genes in everyday life. We draw on discourse analysis to study accounts of overweight in six group interviews with people who are and who are not overweight. The results show potentially contradictory normative orientations towards behavioural explanations of (over)weight. Overt gene accounts are interactionally problematic (in contrast to more indirect accounts such as 'build'), indicating that participants treat 'behaviour' as the normatively appropriate explanation for overweight. At the same time, however, healthy behaviour is an accountable matter, i.e. it is dealt with in interaction as behaviour that is not self-evidently right but requires an explanation. It is discussed how bringing these interactional concerns to the surface is essential for understanding future users' response to nutrigenomics and emergent technologies more in general.

No abstract