Genes are the blueprint for our body’s form and function, but our epigenetics control how our genes are expressed (R).
For example, all the cells in our 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 acted upon by our cellular machinery.
All our genes are encoded in about three billion base pairs within the double helix, which is coiled, super tight around proteins called histones and then these histones coil around themselves to form a supercoiled DNA and protein structure.
This supercoiled structure eventually allows all our 23 unique pairs of chromosomes to fit inside the six-micron nucleus of your cells. If the DNA from one of your cells was unfolded and your chromosomes were put end to end, it would stretch out about 2 meters! 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 needs to read the DNA and produce the proteins 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).
These include:
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
Phytochemicals – retinoic acid, resveratrol, curcumin, sulforaphane, fatty acids, isothiocyanates, allyl compounds, and tea polyphenols (R, R2).
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 the activity of enzymes that can transfer methylate our dna, such as 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 of obesity, cancer, and other diseases (R). To offset the risk of epigenetic diseases in their offspring, maternal nutrition and sufficient vitamin D blood levels are 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.
Always talk to your doctor about any health interventions you’re planning.
Here’s a cool video that shows the complexity of our genome and how it is packaged, replicated, and used to make proteins.