Nutrigenomics, Epigenetics & MTHFR
Nutrigenomics and epigenetics are two fancy words that have circulated around the world of medicine for decades. If you see a functional or an integrative health practitioner, you may be familiar with one or both of these words. Let’s break it down into simpler terms:
Epigenetics is a term that is used to identify how the environment interacts with our genes. Epigenetic research has shown that our lifestyle choices, our environment, and our exposure to toxins can actually impact how genes are expressed. Genes that are expressed explain some of our differences, including our individual vulnerabilities to certain health conditions.
Nutrigenomics is the study of how nutrition affects the expression of genes. Scientists have learned that vital nutrients give your cells all of the building blocks they need to carry out the chemical reactions in your body. This includes the turning on and off of genes.
According to Psychology Today, “One major type of epigenetic mechanism, called DNA methylation, occurs when molecules called methyl groups attach to certain pieces of DNA, which can affect a gene's activity, turning its expression ‘on’ or ‘off.’
What Role Does Genetics Play in All of This?
Single nucleotide polymorphisms (SNPs) are the most common type of genetic variation among people. You may be surprised to learn that over 99% of the human genome is identical between individuals. SNPs are locations within the human genome where the type of nucleotide present (A,T,G, or C) can differ between individuals.
Every part of the body’s methylation pathway can be influenced by SNPs. One of the more popular and well-studied genetic SNPs is methylenetetrahydrofolate reductase (or MTHFR). Some genetic SNPs like MTHFR can also predispose us to symptoms like anxiety and depression among others.
What Genetic SNPs Should Be Tested?
To see if you have a genetic mutation, there are two SNPs that are most commonly looked at. These are MTHFR 677 and MTHFR 1298. When a mutation is present on one of the genes it is called a heterozygous polymorphism (i.e. MTHFR C677T or MTHFR A1298C) and this might cause a 30% reduction in folate enzyme function. When a double mutation is present on one of the genes it is considered a homozygous polymorphism (i.e. MTHFR 677TT or MTHFR 1298CC) and might result in a 50%+ reduction in folate enzymatic activity. If you are like some, you might have what’s called a compound heterozygous mutation which is a single mutation on each SNP type (i.e. MTHFR C677T and MTHFR A1298C) and this could cause a reduced folate enzyme activity rate of up to 70%. So treatment might look different depending on which mutation you have. Please note you can learn more about MTHFR SNPs here, also, it’s worth noting that there are more than 60 different MTHFR SNPs - but the ones most often tested for are the two that have the most research dedicated to them (the 677 and 1298).
I Thought You Said We Have Some Control Over This?
Although you don’t have control over the genes you inherit, science is slowly revealing that you may have control over how some of these genes are expressed. If you get tested and discover that you have an MTHFR variance, understanding nutrigenomics could help you.
For those with two or more variants of the gene (those who are homozygous for the gene or compound heterozygous for it), it is essential to avoid processed foods and foods fortified with folic acid. Folic acid is unable to be properly utilized by the body of individuals with MTHFR variants, causing a buildup of unusable folic acid in the bloodstream and on the folate receptors (blocking them from doing their downstream conversions and generally inhibiting some of the body’s fundamental health processes).
Eating foods that are rich in folate (i.e. leafy greens like spinach, kale, chard and cruciferous vegetables like broccoli, cauliflower, and cabbage) is helpful, but only if you are careful to avoid folic acid. If folate enters the body through food and there is too much folic acid on the folate receptors, it cannot be absorbed and used. But even dietary folate has trouble being properly converted in the body by an individual with an MTHFR variant.