Your genes are the blueprint for how your body can function, but your epigenetics control how your genes are expressed (R). For example, all the cells in your body share the same DNA, yet whether a cell becomes a skin cell, bone cell, or a cancer cell, is determined by how the DNA in that cell is expressed.
All our genes are encoded in about three billion base pairs within the double helix, which is then coiled up super tight around proteins called histones and then coiled up again. All this coiling eventually allows all our 23 unique pairs of chromosomes to fit inside the six-micron nucleus of your cells. If this same DNA from one of your adult cells were completely unfolded and your chromosomes were put end to end, it would stretch out about 2 meters! Crazier yet, is the fact that if all your cells DNA was unraveled, it would be about 2 x 10^13 meters long or 70 trips to the sun and back (R)!
While it’s nice to have our DNA condensed so it can fit in our cells, a downside of this tight wrapping is that our DNA is inaccessible to cellular machinery which reads the DNA, and produces the proteins needed for the cell to function. Fortunately for us, our body has a way to change select portions of our chromatin, to control how our cells function.
The most common form of reducing gene expression or gene silencing usually happens when the proteins attached to our DNA, our histones, gain a methyl group and become more condensed. On the other hand, our genes are usually more active after they gain an acetyl group, and unravel.
Besides methylation and acetylation, there are other forms of epigenetic regulation, including; phosphorylation, ubiquitylation, and sumoylation, yet the main epigenetic changes that most research talks about relates to methylation and acetylation.
Studying the epigenome is important because it can be used to predict and fight diseases. As we age, our epigenome changes (R) and there are also changes in our mitochondrial epigenome (R) which can be used as a marker of aging and also tell us about our disease risks.
Our epigenome is also important to study because it influences our brain performance (R), cancer outcomes (R, R2), cardiovascular disease risk (R, R2), depression (R, R2), and other aspects of our health.
Many of the things that may have beneficial influences on our epigenetics work by influencing S-adenosylmethionine (SAMe) and S-adenosylhomocysteine levels and/or directing the enzymes that catalyze DNA methylation and histone modifications (R, R2).
Vegetables – contain folate, magnesium, iron, phytochemicals, and many other nutrients needed to help regulate our gene activity.
Beets – contain Trimethylglycine, AKA betaine, which can donate a methyl group to our histones and change the expression of our genes (R).
Choline – methyl-donor found in egg yolks and lecithin.
SAMe – methyl group donor and endogenous chemical cofactor (R).
Methyl-folate (methylated folate) – methyl donor
Methylcobalamin (methyl form of B-12) – methyl donor
Our microbiota also affects our epigenome by producing metabolites that can inhibit our histone deacetylase enzymes (HDACs), like beta-hydroxy-butyrate, which can alter gene activity and potentially reduce colon cancer rates (R).
While many of these nutritional supplements and foods work by donating methyl groups or modifying methyltransferases, all diseases do not simply happen because our genes are undermethylated. In fact, we may have over-methylated genes that are causing our problems, or problems completely unrelated to our epigenetics.
Some research has shown that HDACs may be able to reverse certain diseases by modifying the epigenetics of certain DNA regions, by opening up certain parts of the genome and allowing for their proper expression. Some of these HDACs include; trichostatin A, Valproic acid, and Butyric acid. These histone deacetylase inhibitors can have side-effects and modifying them should not be done haphazardly.
While we can change our epigenome, we inherit part of our epigenome at birth, and this can increase our risk for obesity, cancer, and other diseases (R). To offset the risk of epigenetic diseases in their offspring, maternal nutrition and vitamin D status is crucial before and during pregnancy. (R, R2, R3)
Other things that can negatively affect our epigenetics include:
Heavy metals, pesticides, car exhaust, tobacco smoke, polycyclic aromatic hydrocarbons, hormones, radioactivity, viruses, bacteria, inherited and basic nutrients (R).
Despite the complexity of the epigenome, and how much we have to learn about it, it’s important to always focus on the basics of living healthy by eating well (R), exercising (R, R2), getting quality sleep (R, R2), and some sunshine (R, R2, breast cancer).
There is much research that still needs to be done to validate the safety of modifying our epigenetics, so extreme caution is advised before attempting to take any drugs or supplements that can impact your health. Talk to your doctor about any health interventions you’re planning.