Epigenetics: What the Hell is That?
If you have been following the world of health and wellness lately you certainly have seen the explosion of genetic testing from companies like 23andMe or Ancestry. In fact, in April the FDA stated it would allow 23andMe to sell testing for disease risk directly to consumers a landmark decision and big reversal from the FDA’s previous stance on the issue.
You have also likely seen the increase in companies providing direct to consumer genetic interpretations of their DNA in order to improve and personalize their training regimens, diet, recovery, supplements, etc. There are many great companies out there who are providing these types of services like Athletigen based out of Canada or DNActiv8 based out of the UK and run by my good friend James Brown (side note, DNActiv8 is a brilliant name as is Athletigen and I am very jealous they have taken them!). However, buyer beware there are also some really poor companies out there providing these services.
Finally, if you have REALLY been paying attention you may have heard of the term Epigenetics being thrown around. You probably then stopped, scratched your head, and said “What the hell is that?” and you would be in good company with the majority of individuals, including my family.
Is there any more room for me, in those genes?
Sorry, had to get my Ginuwine jokes out early before I ruined the post.
Epigenetics in the literal sense means “above the genes.” It refers to molecular changes that occur to the DNA that alter the way the genes get expressed. My favorite description of epigenetics is that it behaves like a dimmer switch. Instead of turning the genes on or off, epigenetics simply increases or decreases the number of proteins that the genes will make (the central dogma of biology is DNA makes RNA which makes Protein).
Epigenetic marks explain how a stem cell can transform into a specialized cell that functions as a liver, brain, or heart cell. They tell certain areas of the gene to be expressed and others to be silent.
Think of identical twins, they have the exact same DNA, yet they can have physical characteristics that are different. Perhaps one twin is slightly taller and weighs more. Why don’t they look exactly the same with the same DNA? Their individual environments have created their own unique epigenetic changes which in turn make them each slightly different in their physical expression.
Epigenetics is interesting because unlike DNA mutations (actual changes to the DNA bases), epigenetics keeps the DNA code the same, simply increasing or decreasing the use of certain genes. Epigenetics is even MORE interesting, because it allows us to take our “predetermined” genetics, and provides us the opportunity to shift the upper and lower limits of our genetic abilities (more on that below).
DNA is in every single cell in our body and each DNA molecule contains roughly 23,000 genes. Sometimes the terms can get confusing so let’s clear that up now:
- DNA: This is the double-helix structure that most are familiar with. DNA contains the bases Adenine, Cytosine, Guanine, and Thymine and makes up all of our genetic information. When we refer to bases, this is what we mean.
- Gene: Genes lie within the DNA. This is the section of DNA that will “code” for certain proteins or functions. These can range from a few hundred bases to a few million.
- Chromosome: When DNA is tightly wound it forms fibers which then form chromosomes. Think of the 23andme logo. We have 23 pairs of chromosomes per cell or 46 individual chromosomes.
How does the DNA get wound into the chromosome shape? Histones.
Histones are proteins that the DNA wraps around roughly 1.5 times to form structures called nucleosomes which further build to form chromosomes.
Now that we have a better understanding of the molecular structure of DNA, let’s look at how epigenetic marks make changes to our gene expression.
How Epigenetic Marks Change our Gene Expression
The two epigenetic changes you need to know about are changes to the histone structure and methylation at locations called CpG islands.
As discussed above, histones wind the DNA into the shape of chromosomes. However, when DNA is being “read” to create proteins (DNA to RNA to Protein) the DNA has to be in an “open” state to be read by the proteins that will create the RNA. The histones unwind the DNA, creating space. This open state is called euchromatin and leads to the production of more proteins.
When DNA no longer needs to be read, the histones wind the DNA tighter so that the proteins can no longer attach and create the RNA. This is called heterochromatin and when in this state, fewer proteins are made.
The histones know which shape to take because of molecules that attach to the ends of the histones called histone tails. If a molecule called an acetyl group binds to the tail, the histones open and more proteins are created. If a molecule called a methyl group binds, depending on where it binds to on the tail, the histones either open or close.
Hence, epigenetic changes on the histone change how much a gene is expressed.
The other important epigenetic mark is an addition of a methyl group directly onto the DNA at locations called CpG islands. CpG islands are locations on one side of the DNA double helix where the DNA base Cytosine is placed next to the base Guanine repeatedly. This is an uncommon thing to happen on DNA. Proteins that attach to DNA to make the RNA which makes more proteins, use these CpG islands as a marker to tell them where to start reading the DNA at.
When a methyl group is added to the CpG island, the proteins can no longer bind to that region of the DNA and the expression of the gene is decreased.
Ok, I’m done geeking out, let’s get back to the hard questions here.
For some good pictures illustrating the concepts here check out this link.
Well, YOU should. I’ll explain why.
When you were born Mom and Dad gave you the DNA that you are stuck with for life. You can’t change this outside of a radioactive spider bite to the neck or checking out a nuclear reactor up close which I don’t recommend.
So you are stuck right? Your destiny is determined by the fact that no matter what you will always end up bald just like all the other males in your family(Thanks, Mom and Dad).
Well, not really. Thanks to epigenetics we can perform what I like to call an epigenetic vertical shift©
Sorry, I thought the copyright mark would be hilarious.
An epigenetic vertical shift means that though we have our physiologic limitations based on our DNA code, we can shift our top limits upward to beyond what we thought was possible. As we now know from our previous science discussion above, we can also use our dimmer switch to increase production of proteins that we want to occur and decrease proteins that we don’t want to occur.
The science of epigenetics isn’t (YET) at the point where we can say that performing “X” activity causes “Y” gene to be changed. Also, many epigenetic changes fall into a category called common variants. Common variants are used to describe genes that increase your chances of having a certain ability or trait, but having that variant alone is not enough to say that you will with certainty have X or Y ability.
For example, MSTN is a gene that produces the protein myostatin which regulates muscle growth. Certain variants of the MSTN gene are associated with increased muscle growing capabilities while other variants are associated with the opposite. So if you have the favorable gene you should look like Arnold, right?
Wrong. Studies comparing weightlifters with the favorable MSTN gene profile did not have a huge variance in muscle versus their non-favorable gene counterparts. Muscle growth is regulated by other genes like IGF-1, MYOG, BMP2, and many others. Each gene variant contributes a small portion to your overall muscle building ability.
Also, your training regimen, diet, sleep, stress, hormone level, and environment all give epigenetic marks to your DNA. Even if you have a favorable muscle building profile, if you are not optimizing all aspects of your life, your genes could be down or up-regulated causing you to not fully express that gene. The person who is optimizing their lifestyle with a “weaker” genetic profile, through epigenetic changes, could surpass your natural genetic ability.
What can I do with this new knowledge?
Basically, what I want to point out is that you are not defined by your genetics. Yes, you do have limitations. Perhaps your genes won’t allow you to become the next Michael Phelps, Bo Jackson, Aaron Rodgers, etc. but you could potentially play sports at an elite level and compete if you optimize your lifestyle (we use a system-based approach here at Precision Performance).
At a minimum, it tells us that we are not bound by our genes in a health sense. Even if we are at risk for a disease such as Alzheimer’s we can adjust our risk accordingly through lifestyle and epigenetic vertical shifts.
My main work is with athletes and other top performers, but my message is the same for everyone. By making small gains in all areas of your life, you can shift your genetic potential, and improve your health, happiness, and wellbeing. Epigenetics is just the tool we use to get us there.
Precision Performance | Legendary Results
Do you have your genetic profile from a company like 23andMe or Ancestry? I can provide coaching services to help you optimize your training and unleash your inner legend. Send me an email at Ryan@prxperform.com to learn more.