Nutrigenetics is the study of how genetic variation in individual genes affects an individual’s response to particular nutrients and toxins in the diet.
Nutrigenetics aims to use genotype information from an individual to determine the properties of the proteins coded by certain genes and the effect this has on metabolism, transport and assimilation of nutrients in the diet and the effect on elimination of toxins. A genetic variation, e.g. a SNP, can affect the activity of an enzyme which can affect the metabolism of a nutrient such as folic acid. This is exactly analogous to pharmacogenetics where the variation in a gene affects the rate of drug metabolism.
We have standard guidelines on healthy eating which are based on many years of accumulated scientific evidence mainly from observational and intervention studies (NOT clinical trials). These guidelines have been developed to help maintain a healthy lifestyle for as long as possible. The aim of nutrigenetics is to be able to modify standard dietary guidelines according to the individual genotype and phenotype – again based on many years of accumulated scientific evidence mainly from observational and intervention studies. The level of evidence for nutrigenetics is similar to that used to develop and justify standard guidelines.