Whereas the focus of this textbook is on the ways in which genetics affects the body's response to nutrients, this is one of many factors that explain variations in health status observed among individuals. The medications to which our bodies are exposed is another factor that can affect our health status, and genetic variations can alter the way these medications are processed in the body. The emerging field of pharmaconutrigenetics lies at the intersection where genetic variation shapes individual responses to the combination of nutrients and drugs. In the future, a feature of precision medicine will likely incorporate individualized therapies that tailor both nutritional and pharmacological interventions in closely coordinated fashion to achieve better outcomes in the prevention and treatment of diseases. Some clinical sites have started to use genetic testing as a valued component of patient care to guide nutrition and drug interventions, although widespread adoption has not yet occurred. For many genes, there is enough evidence for its incorporation into patient care because the impact it has on health is well-defined, but barriers to moving genetic information into patient care are associated with implementation challenges. Factors such as a lack of training among health care providers or a lack of supporting infrastructure within the health care system to integrate genetic information efficiently within electronic health care records are some examples of major implementation barriers that are keeping genetic information from being integrated into patient care. In addition, the nutrition and pharmacy fields do not typically collaborate to ensure that the interventions with which they are providing patients work synergistically. Shifting toward stronger collaboration between the fields could improve outcomes in the prevention and treatment of many diseases. Background information on the main genes implicated in drug biotransformation and several examples of the genetic impact on nutrient–drug interactions will be offered to demonstrate some ways in which the nutrition and pharmacy fields can work collaboratively to achieve better patient outcomes.
