Leaping "out of the doubt"--nutrition advice: values at stake in communicating scientific uncertainty to the public.

This article deals with scientific advice to the public where the relevant science is subject to public attention and uncertainty of knowledge. It focuses on a tension in the management and presentation of scientific uncertainty between the uncertain nature of science and the expectation that scientific advisers will provide clear public guidance. In the first part of the paper the tension is illustrated by the presentation of results from a recent interview study with nutrition scientists in Denmark. According to the study, nutrition scientists feel their roles as ''public advisers'' and ''scientists'' differ in that the former involves an expectation that they will provide unambiguous advice of the kind that might relegate scientific uncertainty to the background. In the second, more general, part of the paper we provide a normative analysis of different strategies of dealing with the tension. The analysis is structured around the extremes of either total concealment or full openness regarding scientific uncertainty. The result of analysis is that scientific advisers should not simply ''feed'' scientific conclusions to the public. They should rather attempt to promote the ability and willingness of the public to assess and scrutinize scientific knowledge by displaying uncertainties in the scientific basis of advice. On the other hand, scientific advisers must accommodate the public's need for guidance. Such guidance should be restricted by careful consideration of what it is relevant for the public to know in order to evaluate scientific advice in practical terms.