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? 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. (shrink)