A Scoping Review of Direct-to-Consumer Nutrigenetic Testing: Mapping Genes and Associated Nutrition Recommendations

Consumer demand for autonomy in their own health care is fueling the rise of personal genetic testing. Nutrigenetics tests promise tailored dietary recommendations to help consumers achieve their health and well-being goals. To support informed decision-making by both practitioners and consumers, there is a need for a comprehensive evaluation of the current market landscape and the specific nutrition claims being made. A scoping review was completed via an internet search. Companies that provided direct-to-consumer tests with nutritional recommendations were included. Nonhuman, or pediatric tests, and tests requiring a health practitioner to order were excluded. Genes and nutrition recommendations used in the testing panels were mapped, and company characteristics were summarized. The review was prospectively registered with Open Science Framework (DOI: 10.17605/OSF.IO/A4K2R). There were 104 companies providing 204 nutrition-related testing panels that were included. The mean cost was US$234, with North America the most common continent of company registration. Only 56 (54%) companies publicly disclosed the genes used to make nutritional recommendations, with 3309 unique genes identified across testing panels. Micronutrients (n = 1593 genes), cardiovascular health (n = 1446 genes), and weight loss (n = 1383 genes) were the most commonly reported nutrition categories. Posttest support was provided by 55 (53%) companies, but this was often at additional cost (n = 33), and the qualifications of those providing support varied greatly. The expanding nutrigenetics market continues to be unregulated, with high variability in offerings. With thousands of unique genes linked with nutrition recommendations, it is challenging for healthcare practitioners and consumers to keep pace with this dynamic market. Evidence analysis and resources are required to support healthcare practitioners to provide consumers with evidence-based guidance and ensure their best interests are protected.