Time to put your science caps on folks. I promise this won't get too heavy, but this is a warning that there is some mild science content ahead.
I'd like to share a fascinating research article from a few years ago.
OK, so we all know that every single cell in our bodies has DNA. Remember that double-helix structure you learned back in biology class? Well, your DNA sequence is one thing that determines your "genes." Even though every cell in your body (except your sperm/eggs and immune cells) has the same chromosomes and the same DNA sequencing, they look and behave drastically different!
There are a whole list of cast and characters involved with how your DNA sequencing is "transcribed" into various functions and operations that your body uses for day-to-day operations. One of these factors is known as DNA methylation.
DNA methylation changes the expression of genes, usually decreasing it (the decrease in the expression of one gene might increase the expression of another). These so called epigenetic changes influence cell behavior, and are ultimately responsible for cell identity, i.e. it's what makes your skin cell different from your heart cell even though skin cells have the same DNA as heart cells. Remember this stuff yet?
The researchers in this study found that regular exercise for 6 months changed the methylation states of many genes in our fat (adipose) cells, including 31 genes specific to obesity and diabetes type 2, reducing their expression level a small but significant amount, <10%.
So why/how is this relevant?
This study has shown that our cells are identifying and changing based on extrinsic factors such as exercise. Not only is exercise making a ton of other 'good' things happening in your body, but it is apparently changing the way your cells function on the most basic level!
It is entirely possible for these changes to your DNA to be heritable. So, a healthy, active person could be giving their offspring a head-start with healthier genes. This is a double-edge sword of course, because not only could you be giving your child a slight genetic advantage by staying active, but the reverse could be true too and you could be starting them a step behind others by being inactive.
One thing that should be noted about this study, and noted for potential future studies, is how stable these changes are. Does one workout cause your DNA to methylate forever? For one day?
For a week? We know that methylation is reversible, so maybe not exercising for a specific amount of time may reverse the positive effects, who knows!
There are a lot of important questions raised here, as with any worthwhile scientific study, but it is really exciting to think of the possibilities that this field of research is heading. Keep an eye on this blog as there will be plenty more research shared from the field of epigenetics!
Tyler Robbins B.Sc., CSCS
Director of Fitness
Head of CrossFit