Nutrigenomics in the News

In a way, it’s kind of cool that genetic testing is now available at the drugstore. The New York Times today carries a story about Sorenson Genomics which has started selling a paternity test kit through Rite Aid stores in California, Oregon and Washington. Left unexplored in the Times story was the backstory about why uncertain paternity might be a significant problem to the point of being a market segment for a test kit (if that’s too oblique, it’s the question about who’s banging who). But what’s of interest to me is the spread of genetic testing directly to consumers. Genetic tests, for health and diet advice, ancestry and paternity, are already available directly to consumers through the Internet.

Nutrigenomics holds the promise of being able to identify how genetic variability and diet might combine to create health disparities in human populations. According to the National Center for Minority Health and Health Disparities (NCMHD) Center for Excellence in Nutritional Genomics, the goal of nutrogenomics is to. . .

. . . reduce and ultimately eliminate racial and ethnic health disparities resulting from environment x gene interactions, particularly those involving dietary, economic, and cultural factors. Our goal is to devise genome-based nutritional interventions to prevent, delay, and treat diseases such asthma, obesity, Type 2 diabetes, cardiovascular disease, and prostate cancer.

In addition, there is an evolution in the field of toxicogenomics, which attempts to understand health effects associated with the interaction of genes and environmental toxicants. Advances in toxicogenomics have been spawned by the results from the Human Genome Project, which has characterized in detail the composition of DNA in human cells. Toxicogenomic methods have allowed researchers to begin studying toxicant-induced genomic expression, with applications such as screening chemicals for hazard identification, monitoring toxicant exposure, assessing mechanisms of toxicity, and predicting individual variability to exposure to toxicants.

Toxicogenomics holds the promise of enhancing our ability to estimate the risks from chemicals in the environment. While the value of toxicogenomics in assessing health risks is widely recognized, there are limitations to the methods and data currently available, and further work is needed to fully understand and apply the results from toxicogenomic studies. As yet, there is no coherent regulatory framework for managing environmental health hazards with toxicogenomic methods. Finally, there are social implications to be considered from toxicogenomic applications. For example, there are legal and ethical consequences associated with the ability to specifically identify individuals who may be genetically susceptible to exposure to specific toxic substances.

The National Research Council (NRC) has recently published a report examining the potential impacts of toxicogenomics on predictive toxicology. This report was prepared at the request of the National Institute of Environmental Health Sciences (NIEHS). The report recommends that regulatory agencies enhance their efforts to incorporate toxicogenomic data into risk assessments. However, these data currently are not adequate to replace the current testing programs used in regulatory toxicology. The report makes recommendations for improving the capabilities of toxicogenomics in the areas of exposure assessment, hazard screening of chemicals, and evaluation of population variability and individual susceptibility. Toxicogenomics also has the promise of improving dose-response assessment by providing insights on mechanisms of action, improving the confidence in cross-species extrapolation, and improving understanding of effects with low-dose exposures, particularly developmental effects that might occur with early-life exposures.

Which brings us back to over-the-counter genetic testing. The Times story draws attention to Myriad Genetics which markets a test for the presence of mutations in the BRAC gene which is an indicator of susceptibility to breast cancer. Apparently the BRAC1 and 2 genes are intellectual property of Myriad’s, a development that has some people salivating at the financial opportunities and at the same time, made me rapidly aware of how little I know about this expanding market segment. Last year, the National Academy of Sciences published a study, at the request of the National Institutes of Health, on the granting and licensing of intellectual property rights on discoveries relating to genetics and proteomics and the effects of these practices on research and innovation.

According to the Times, Myriad engendered some controversy over releasing a breast cancer test kit, though it doesn’t go into any of the details (while that’s a topic for another day, a little of the story is here).

Congress asked the Government Accountability Office (GAO) to investigate Internet companies which offer health or nutritional counseling based on genetic testing. The GAO’s results, true to form, identified the potential for fraud and abuse, with testing companies recommending expensive nutritional supplements to address so-called genetically-related health problems. Legislation may be forthcoming. I’m in faint agreement with the author of the American Spectator article about the usefulness of additional regulation. What we need instead are better-educated consumers.