Nutritional genomics is an evolving health science which studies the human genome and the use of food as medicine to treat individuals according to their specific genetic needs. Food can influence how cells behave through gene expression, and so proper nutrition may prevent or treat diseases. Changes in genes, such as mutations, may also change an individual’s nutrition requirements or require the person to avoid certain foods. A mother’s nutrition may influence her children’s and grandchildren’s gene expression. Orthomolecular medicine is related to nutritional genomics in that is uses nutritional supplements as medicine.
Genetic variations may cause an individual’s nutrition requirements to differ from most other people's requirements. For example, people with phenylketonuria, a disorder in which people are unable to process the amino acid phenylalanine and can lead to central nervous system and brain damage, may need to avoid foods that contain phenylalanine. Some common sources of this amino acid are eggs, milk, and aspartame.
Nutritional deficiencies can lead to serious health problems, and some may damage DNA. Some examples include vitamin B12, zinc, and vitamin C deficiencies. Vitamin B12 deficiency may lead to neurological damage, brain dysfunction, colon cancer, and heart disease. Those who are deficient in zinc may be more susceptible to brain and immune dysfunction, and this deficiency can damage DNA through chromosome breaks. A lack of Vitamin C can lead to DNA oxidation, which may result in cataracts and cancer. These may be treated by including foods with sufficient nutrients.
Poor nutrition can effect both an individual and her descendants. Some research, such as studies done to observe the effects of starvation and low birthrates, indicates that a woman’s health habits, including nutrition, can effect her child’s health. In some cases, her grandchildren’s health can also be effected.
The three subcategories of nutritional genomics are nutrigenetics, nutrigenomics, and nutritional epigenomics. Nutrigenetics is concerned with the effect gene mutations, which may be prompted by nutrition, have on health. Nutrigenomics studies the effect that nutrition, along with toxins and stress, has on gene expression.
Nutritional epigenomics is also concerned with nutrition, gene expression, and inheritance. The results of any of these categories of nutritional genomics studies may be used in developing nutritional guidelines for optimizing public health, encouraging healthy aging, and preventing disease.
This field is somewhat similar to orthomolecular medicine, which uses nutritional supplements to prevent or treat disease. Orthomolecular medicine was founded by Dr. Linus Pauling, who is well-known for using Vitamin C supplementation to treat colds. Another example of using supplements as medicine is lithium to treat schizophrenia.