Did you know DNA can affect your nutritional status?
Vitamins, Minerals and Genes - Personalizing Your Supplements
Do you take vitamin pills or load up on vitamin C to ward off that cold? Are you worried that your diet might not give you all the nutrients you need? Nutrition has always played a large role in our lives. Vitamins and minerals are on the news at least once a week, with claims that they provide protection from a disease, or aid in a cure. The latest revolution that fits this bill is nutritional genomics, which is personalizing your nutritional needs to match your genes.
Nutritional genomics studies the link between genes, nutrition and human health. Nutrigenetics is the branch of nutritional genomics that focuses on how genetic variations influence the absorption, utilization and metabolism of vitamins and nutrients. Nutrigenetics research mainly focuses on one type of genetic variation, known as a single nucleotide polymorphism (SNP). The DNA code is composed of four nucleotides, organized in a specific pattern to code for all our different genes. When individuals differ by a single nucleotide, this change is called a SNP. The ultimate goal of nutrigenetics is to create a map of all the genetic differences that can influence diet, health and nutrition, allowing us to customize our lifestyle in terms of what we eat and how we exercise based purely on our genetics.
The MTHFR gene encoding methylenetetrahydrofolate reductase is one great example of how genetic variation and vitamin intake can influence each other and impact human health. Methylenetetrahydrofolate reductase is an enzyme that breaks down folate (vitamin B9). A specific genetic change in MTHFR is linked to a higher risk of heart disease, schizophrenia and certain types of cancer. People with this altered form of the MTHFR gene produce much less enzyme, so they can’t process folate from their diet properly. Luckily, there is a simple fix to this problem – folic acid supplementation. Folic acid is the synthetic form of naturally occurring folate, and according to a study from the University of Berkeley, providing extra folic acid prevents the increased health risks associated with the MTHFR variant.
Iron is another nutrient that is affected by genetic variation. Defects in the HFE gene cause a genetic disorder known as hereditary hemochromatosis. This disorder is characterized by excessive absorption and storage of iron. We are unable to naturally dispose of extra iron in our body, so any excess iron accumulates in our organs, eventually causing massive organ damage. Hemochromatosis is a relatively common genetic disease, affecting 1 out of 200 individuals in the US, but it is often misdiagnosed or diagnosed too late after organ damage has already occurred. If diagnosed early, hemochromatosis can be easily treated through dietary changes to reduce iron intake, and blood donations to remove excess iron from the bloodstream. On the flip side, there are also other changes in genes (e.g. TMPRSS6) that reduce the absorption and transport of iron around the body, increasing the risk of iron-deficiency anemia.
Studies have identified multiple genetic changes that can influence the absorption and break down of vitamins and minerals. Apart from the role nutrigenetics plays in identifying and preventing diseases, these findings can impact our lives more broadly. For instance, the current recommendations for dietary allowance for vitamins, primarily made based on age and gender, will soon need to be revised and more personalized based on genetics. This also means that the generic vitamin supplements from the drug store are not suitable for everyone. As advances in DNA sequencing technologies revolutionize the field of nutrigenetics, you may soon expect your doctor to recommend an individualized vitamin and supplement plan that will match your unique genetic makeup.