Nutritional genomics has reached the public through applications of the Human Genome Project offered direct to consumers (DTC). The ability to pursue nutrigenetic testing without the involvement of a health care professional has received considerable attention from academic and policy commentators. To better understand the knowledge and attitudes of Canadian health care professionals regarding nutritional genomics and nutrigenetic testing, qualitative research in the form of focus group discussions was undertaken. Four key themes emerged: (1) concerns over DTC testing; (2) lack of health care professional competency; (3) genetic scepticism and inevitability; (4) expectation of regulation. Together, they indicate that health care professionals have little knowledge about nutritional genomics and hold contradictory attitudes towards genomics in general, and to nutritional genomics in particular. Respondents argue in favour of a delivery model where health care professionals act as intermediaries. They are also aware of their lack of competency to provide such services. To ensure greater public protection, respondents cite the importance of more stringent regulatory oversight of DTC genetic testing. Whether such an approach is necessary to address the various ethical and social issues raised by nutrigenetic testing remains an open debate.

This review examines the extent to which transcriptomic methods have lived up to their promise in the context of nutrition research, placing particular emphasis on examples from micronutrient research. A case is made that the high quality platform technologies now available, together with established standards and systems for data storage and exchange and powerful new methods of data analysis, mean that microarrays have reached a level of technical maturity at which they can be exploited to their full potential. In the context of nutrition and micronutrient research, transcriptomic methods have already been widely applied, albeit primarily in studies using cell lines and animal models. Using this type of approach, a multitude of genes regulated at the mRNA level by dietary components has been identified and this, in turn, has provided new insights into the biological processes affected by nutritional parameters. Evidence from the very limited number of published transcriptomics-based nutritional studies performed in human volunteers suggests that, with appropriate study design, it is feasible to apply transcriptomic methods successfully in dietary intervention trials. On the other hand, gene expression-based biomarker development still poses a major challenge. Here the use of expression profile ‘signatures’, rather than single genes, may provide a solution. Approaches designed to identify such ‘signatures’ are being developed and tested widely, primarily in the context of medical research. The applicability and power of such approaches should also be evaluated in the context of nutrition.

To be able to perform a comprehensive and rigorous benefit-risk analysis of individual food components, and of foods, a number of fundamental questions need to be addressed first. These include whether it is feasible to detect all relevant biological effects of foods and individual food components, how such effects can confidently be categorised into benefits and risks in relation to health and, for that matter, how health can be quantified. This article examines the last of these issues, focusing upon concepts for the development of new biomarkers of health. Clearly, there is scope for refinement of classical biomarkers so that they may be used to detect even earlier signs of disease, but this approach defines health solely as the absence of detectable disease or disease risk. We suggest that the health of a biological system may better be reflected by its ability to withstand and manage relevant physiological challenges so that homeostasis is maintained. We discuss the potential for expanding the range of current challenge tests for use in conjunction with functional genomic technologies to develop new types of biomarkers of health.

The link between genome instability and adverse health outcomes during the various stages of life, such as infertility, fetal development and cancer, is briefly reviewed against a background of evidence indicating that genome instability, in the absence of overt exposure to genotoxins, is itself a sensitive marker of nutritional deficiency. The latter is illustrated with cross-sectional and dietary intervention data obtained using the micronucleus assay, an efficient biomarker for diagnosing genome instability and nutritional deficiency. The concept of recommended dietary allowances for genome stability and how this could be achieved is discussed together with the emerging field of nutritional genomics for genome stability. The review concludes with a vision for a disease-prevention strategy based on the diagnosis and nutritional treatment of genome instability, i.e. ‘Genome Health Clinics’.

As part of its work on setting standards and establishing guidelines for nutrigenomics research, the European Nutrigenomics Organisation (NuGO) is developing bioethical guidelines for those engaged in human nutrigenomics studies. A NuGO working group developed a set of draft guidelines addressing four areas: (1) information and consenting prior to a nutrigenomicsstudy; (2) the generation and use of genotype information; (3) the establishment and maintenance of biobanks; (4) the exchange of samples and data. NuGO convened a workshop with a panel of invited external experts to assess the draft guidelines. The panel of experts confirmedthat these areas are important and that the development of specific bioethical guidelines for nutrigenomics research would therefore enhance the application of established international guidelines in this field of biomedical research.