Have you ever read something, heard someone speak on a topic, had the information, but for some reason the knowledge didn’t particularly impact you all that much? Then, a month or even a year later you hear it again and the proverbial lightning bolt strikes as an AHA moment is born.
I read about epigenetics in Dr. Pamela Peeke’s book, The Hunger Fix, almost a year ago. The Hunger Fix provides a great introduction to the problem of food addiction from both a scientific and behavioral perspective. I frequently recommend the book to my clients. The funny thing is however, her very well-written section on epigenetics didn’t really leave a lasting impression on me -- until I heard her speak at a conference I attended last week. Lightning bolt! AHA!
The prefix “epi” means above or on. Simply defined, epigentics is the study of changes in gene activity that do not involve modifications to the actual genome, or genetic code, because the changes occur on top of the genome. It is a quest to understand why some genes turn off and some turn on, as well as why some genes whisper and some genes yell, even though the gene itself doesn’t change in any way.
At this point, you might be scratching your head a bit wondering where my lightning bolt came from. Wait for it…wait for it. This is the thing, if I am genetically predisposed to obesity or addiction, the way I live can either make those genes louder, or silence them altogether. The way I live can enliven the gene or suppress it. Thus, I can create my own suffering or I can shut the possibility down just through some choices I make in lifestyle and perhaps environment. As Bob Wright so eloquently says, “Lifestyle trumps genetics.” In other words, my genes do not determine my destiny. I have the power to alter the expression of my genes by changing what happens on top of them.
Here’s how it works. We have billions of cells in our body and every cell has the exact same DNA, or genetic code. Your heart cells also have the genes for a liver cell, a skin cell, eye cell, lung cell, tongue cell…you get the picture. There is potential for serious identity issues if your heart cell doesn’t know how to just be a heart cell, right? Enter methyl groups. Methyl groups are organic compounds that bond to the genome and instruct them on how to express themselves. They bond differently to different cells so their instructions for expression are different. For instance, when a methyl group bonds to a skin cell, it tells the genome to say, “Hey, I’m a skill cell” while silencing the liver and heart genes.
The second part of this process involves proteins called histones. Histones coil around the genome and determine how much the gene expresses itself. You can think of methyl groups as a switch and histones as a dial. Histones wound tightly around the genome cause the gene to be expressed less, while loosely wound histones cause the gene to express more. Remember, these histones as well as the methyl groups don’t actually reside within the genome, but rather sit on top of it. Therefore, they influence the way your genes are expressed without actually altering the gene.
Why is this exciting to me? Dr. Peeke explains it well. She refers to histones as genetic referees, “scanning every action you take and choice you make, switching the message that a particular gene will deliver to the rest of the body. Eat junk food and your genetic “speech” or expression changes, resulting in a whole cascade of biological changes, including increased body inflammatory processes. Eat an apple and histones order the gene to start a different cascade, resulting in improved immune function.” Dr. Peeke says that the goal is to have happy histones.
This is some powerful stuff people and we are going to hear a lot more about it in the upcoming years. The way we live and the choices we make have the capacity to change our genetic expression. We don’t have to be slaves to unfortunate heredity. We have the power to influence our bodies and mind on the most basic and profound level…the genetic level.