For Debate: Investment in Nutrigenomics Will Advance the Role of Nutrition in Public Health Free

Nutrigenomics has been defined as “the scientific study of the way specific genes and bioactive food components interact” (2). Speaking for the motion that investment in nutrigenomics will advance the role of nutrition in public health were Professor Peter Morgan, Rowett Research Institute, Aberdeen, Scotland, and Dr. Ben van Ommen, TNO, Zeist, the Netherlands. Speaking against the motion (although admitting afterward that in reality they were for it) were Professor Michael J. Gibney, Trinity College, Dublin, Ireland, and Professor Frans Kok, Wageningen University, Wageningen, the Netherlands. Professor Morgan started off the debate by suggesting that “If you can't measure it, you can't improve it,” pointing out that defining healthy phenotype is a critical aspect to public health nutrition and relevant scientific data are lacking. He also suggested that there is a growing demand for personalized medicine in Big Pharma, health services, and by the public (i.e., people want treatments that work); similarly, there was such a demand in nutrition, which could be met by nutrigenomics. Further, he pointed out that costs for such analyses were decreasing, making it more feasible to consider application of these technologies to population-based studies. Also supporting the motion, Professor Ommen used as the basis of his argument the need for improved biomarkers. He provided as a definition of health status an equation in which health status is equal to the integration of exposures from conception to present multiplied by the genome. He suggested that, although our ability to measure the genome is okay, our ability to measure health status and integrated exposures is “lousy,” and therefore that the role of nutrigenomics is to fine tune the measurement: “Not measuring more; measuring better.”

Taking the stand against the motion, Professor Gibney described nutigenomics as “black-box IT” and suggested that we were in the midst of a “genomic revolution fueled by technology.” In response to Professor Morgan's argument, he countered that we might be operating under a false belief that what is good for pharmacy is good for nutrition. He raised the issues of the lack of standardized technologies and access to relevant tissues, and the inability to distinguish acute and chronic effects of diet, as being roadblocks to applying nutrigenomics to public health. He pointed out that, in public health nutrition, the clinically relevant associations are identified in observational studies. He also concluded that it is best to think of nutrigenomics as another tool. Dr. Kok argued, citing Willett (3) and Stampfer et al. (4), that we do not need nutrigenomics to know what to do to decrease disease risk, and that improving public health is more an issue of changing behavior (e.g., helping the public make changes and negotiating with food companies to make changes to the food supply). He also argued that we do not have the data to support recommendations for individual or personalized nutrition and that there are ethical issues associated with this.

A show-of-hands vote at the beginning and end of the session indicated that the majority of the audience thought the answer to the debated question was “Yes,” although a small, and probably not statistically significant, increase in the number of “No” votes at the end of the session suggested that Professors Gibney and Kok's arguments were able to sway a few in the audience. Some highly quantitative audience members who were on the fence thought that the question, as it read, was not helpful, and that it should have been more specific; that is, “Will investment in nutrigenomics advance the role of nutrition in public health in the next x number of years?” Then, the discussion shifted to what that time frame would be and that turned into another debate in and of itself.

Nutrigenomics uses postgenomic and related technologies (e.g., genomics, transcriptomics, proteomics, metabol/nomics, etc.) and thus is faced with the same technical problems confronting researchers using these technologies in other areas (5). In addition, there are some challenges that are specific to nutrition. In their NuGOweek 2006 welcome address, Ben van Ommen and Fré Pepping touched on one of these: “The major dilemma nutrition research faces is a focus on health instead of disease without the tools to properly quantify health. The challenge in meeting this dilemma will be to capture, quantify, and select the relevant molecular changes amongst the noise of healthy variation and to do this on an individual basis. Thus, nutrigenomics will require a systems biology toolkit adapted to nutritional specifics. This is far from reality.” Unlike early detection research or medicine, which aim to distinguish disease from no disease for example, nutrigenomics seeks to characterize a healthy phenotype and be able to distinguish between a healthy and a predisease state (6). This requires that the omics methods are sufficiently sensitive to detect small differences within a reference range, that studies are designed to address the effects of diet and dietary patterns in healthy individuals, and that the animal model and human data are integrated to provide the necessary mechanistic detail.

Despite all the challenges, the answer is highly likely to be “Yes” to the question “Will investment in nutrigenomics advance the role of nutrition in public health?” After all, the discoveries that certain dietary constituents are essential for life and for prevention of nutrient deficiency–related diseases has advanced the role of, or might even be considered the cornerstone of, public health nutrition in the 20th century. For example, as early as 1,500 BC, probably the first nutritional deficiency disease to be clearly recognized was night blindness, treated by the Egyptians and Greeks with the ingestion or topical application of cooked liver (7). It was not until 1915 and beyond that experimental work identified vitamin A as the relevant factor and paved the way for its inexpensive production and use in prevention of vitamin A deficiency (7). It is easy to imagine how better characterizing the intricacies of nutrient-gene interactions will further our ability to more accurately pinpoint nutrient requirements, as well as define the contribution of other dietary constituents to disease prevention and health. On the other hand, promotion of good health through nutrition and the primary prevention of nutrition-related illness in the population (i.e., public health nutrition) require the application of existing nutrition, behavior, and public health knowledge and the consequent adoption of established dietary recommendations by a population. Fully characterizing dietary exposures and biological responses to them using the available omics technologies and systems biology techniques will improve nutrition knowledge, but the support needs to be there for the next steps—applying and adopting this knowledge. We already know much more than we do: Hafez (14th century Persian poet) said, “learning without doing is the affliction of the learned” (8).

Eagerly, but cautiously, assuming that the nutrigenomics challenges (e.g., technological glitches, study design issues, data integration nightmares, etc.) will be resolved with time, we will have improved nutrition knowledge on which to base further action. Supporting research in a manner sufficient to improve strategies to encourage adoption of healthy lifestyle behaviors, in tandem with the focus on nutrigenomics, is critical if the answer is to be “Yes” to the question “Will investment in nutrigenomics advance the role of nutrition in public health?”