Stop using your genes as an excuse aka Epigenetics
I wanted to take a minute today to discuss a rather complex scientific concept (hopefully) in a way that is relatively easy to understand! Let’s get to it.
Whenever I talk to people about changing their lifestyles, one of the most common (mis)beliefs and objections out there is that their genes are determining their current health or body composition status. And that there is nothing that can be done, because it’s ” meant to be”!
To this I have to blow the BS horn, because while Genes provide the assembly line for our proteins, which are part of every important structure in the human body (i.e. cell components, enzymes, hormones, tissues, organs, etc…), however, it’s our consistent lifestyle habits that ultimately determine which genes express & how they express. This concept is known as Epigenetics and refers to all changes to gene expression in which certain regions of genes are turned on or off in response to environmental cues including nutrition, exercise, sleep, smoking, pollution, etc…
First we need to start by briefly explaining how genes are expressed in our bodies. For an amazing interactive tool for learning about the basics of DNA expression through translation and transcription click here. Very briefly, here’s how things progress: 1) Transcription – occurs in the nucleus of the cell; the DNA strands unzip, and a messenger (m-) RNA produces a complementary copy of the DNA strand; this is then transported out of the nucleus to the Ribosome; 2) Translation – occurs in the Ribosome of the cell; Here the m-RNA is connected with t-RNA and it’s 3-sub-unit chains are built in the appropriate order complementary to the m-RNA strand. This process stops when the STOP CODON is read. The protein then needs to be activated & folded into its functional state. Transcription and translation are possible targets for epigenetics to alter the expression of our genes (among others).
Epigenetics is actually a major player in our ability to adapt to our environment over time & eventually has helped shape our evolution. Figure 1 (citation below) is a great diagram on the interaction between epigenetics and evolution. It simply shows how epigenetics is the way in which the environment including lifestyle habits interacts with our gene structure (genotype) and alters the expression of this, which results in slightly different possible phenotypes. This is essentially the reason behind why genetic twins are not actually identical and why they seem to become more different as they age. You can see a good description and a very well done VIMEO on this concept here (University of Utah).
A study from 2004 showed that not only do nutrition and lifestyle habits affect the death rate associated with cardiovascular disease and diabetes but that these effects are actually passed down to children and grandchildren and depending on the type of stressor (i.e. crop failure, famine, etc…) it could be either protective or putative. Specifically, if a father had inadequate food access during a critical period of development just prior to puberty then his sons were protected against death from cardiovascular disease. Interestingly, death related to diabetes increased for children if food was plentiful during this critical period for paternal grandfather, but decreased when excess food was available to the father.
Epigenetic silencing is one way that genes are turned off and it can contribute to differential expression. This might also explain, partly, why genetic twins are not phenotypically identical. Additionally, epigenetics is important for X-chromosome inactivation in female mammals, which is necessary so females don’t have twice the X-chromosome gene products as males. You can read that article here.
Within cells, there are three systems that can interact with each other to silence genes: DNA methylation, histone modifications, and RNA-associated silencing (Figure 2). You can Google more about how each of these work if you want to geek out on it, but it’s not necessary for our discussion here, except that you understand that you have ultimate control over how many of your genes express based on your daily lifestyle habits!
Sufficed to say, these are all chemical processes (details are unnecessary) that actually change whether a gene section is transcribed into a protein, which contributes to our phenotype (expression) derived from our genotype (actual genetic structure). That’s all I will cover for now. I will delve into this even more in future posts & the Podcast, so be sure to check that out too & subscribe to be notified.
There’s a lot more information being discovered on the human epigenome as more studies are being done. If you want more, please check out the citations & links I’ve provided throughout. However, the bottom line is that our genetic sequence (genotype) is determined by our parents & even grandparents, but which of those genes are turned on or off at any given time (phenotype) totally depends on our consistent lifestyle habits and those are absolutely in our control!
There have been several studies recently that have shown how specific lifestyle changes including exercise and nutrition alter gene expression at a molecular level. I have summarized some of these in my previous posts on telomere length and longevity (here) and living to express your best genes possible (here). Additionally, this is why I honestly believe a Paleo/Primal lifestyle approach is best for health & longevity!
Haven’t you used your genes as an excuse for too long?
Make your life & health what you want of it! The choice is up to you!
Till next time… Have an amazing week!