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Jennifer Grebow is editor-in-chief of Nutritional Outlook.
There is great potential for nutrigenomics in dietary supplements; less so for nutrigenetics.
Nutrigenomic supplements are in the FTC’s crosshairs. The agency recently settled its first deceptive-advertising case against two “personalized genomic product” firms. FTC said the firms claimed their dietary supplements and skin-repair serums-which the companies purportedly customized for consumers based on DNA analysis from customers’ cheek-swab samples-could treat diabetes, heart disease, arthritis, and insomnia. While this is a clear-cut case of unauthorized disease claims, it raises an important point: companies marketing nutrigenomic supplements need to be very careful about how they promote the link between genotyping, disease, and nutrition.
Nutrigenomics, or nutritional genomics, is the study of how nutrition can impact-and potentially improve-human gene expression. For those who study nutrigenomics, the goal is “to devise evidence-based nutritional interventions to prevent, mitigate, and delay the onset of diseases such as obesity, type 2 diabetes, cardiovascular disease, malnutrition, and certain cancers,” says Raymond Rodriguez, PhD, a professor at the University of California, Davis, and director of the Center of Excellence for Nutritional Genomics (CENG).
This goal is valid, Rodriguez says. “The notion of nutritional genomics is that nutrition affects your genes. It affects how genes work and how well they work. That’s the area of research that I think is still very sound.”
Studies show that appropriate nutrition, over time, can help maintain health and possibly also reduce the risk of certain diseases. But, Rodriguez emphasizes, genetic testing for complex, chronic diseases like cardiovascular disease or diabetes is “not very informative.” Complex diseases involve hundreds, or even thousands, of genes. Current genetic tests can only weakly associate a genetic variance with the chance of getting one of these diseases-much less determine numeric values.
Making specific nutritional supplement recommendations based on genetic testing to mitigate disease risk is even harder, Rodriguez says. (This approach is nutrigenetics, as opposed to nutrigenomics, which is what Rodriguez studies.)
Even if you do have a moderate risk of a disease, “Nobody knows for sure what level of supplementation will reduce that risk,” he says. In addition, nutrigenetic supplement firms-the ones that advocate genetic testing-also overlook the fact that other factors influence a person’s risk of disease, including gender, age, lifestyle practices, and environmental exposures.
Still, the promises of nutrigenetic supplements-to reduce disease risk through supplementation-is bound to attract customers, Rodriguez admits. “The nutrigenomic approach is very strong, but it doesn’t have the ‘sexiness’ that’s associated with these genetic tests.” This allure may lead many a customer to pay more for nutrigenetic supplements. According to the FTC, the companies under settlement charged customers more than $100 monthly for their products. In short, genetic testing is “just a marketing ploy to get people to not only pay more for their supplements but also to pay more for a supplement that they don’t even need,” Rodriguez says. “They’re paying a lot and getting very little.”
Instead, he advocates for “smart nutrition” to insure against disease. Eat well, he says. He also promotes the use of dietary supplements.
There is great potential for nutrigenomics, which doesn’t involve DNA-typing, in dietary supplements. It’s clear that individuals have different nutritional needs. For instance, as people age, their ability to absorb nutrients declines. Rodriguez says supplement companies are already doing a good job of addressing the needs of different consumers, in the form of products for men versus women, or for children versus adults or seniors, each of who have different nutritional needs. “That’s how nutrigenomics has gotten into the market,” he says.
But don’t count on genetic testing to provide specific instruction for supplementation. “I don’t have to pay $100, $200, or $400 for a test to get access to information about good nutrition and health,” he says.
Nutritional Outlook magazine