For decades the “central dogma” of genetics was believed to be the absolute truth, and DNA was thought to control everything about how our genes and our inheritance determined who we were…. Whether it be tall or short; fat or skinny; red haired or bald. We believed that at the moment of conception, we inherited half the DNA and genes from our mother, and half from our father. From that moment on, our genetic make-up was cast for life. Our genes would then be passed on to our offspring, unchanged, and untouched. Doesn’t seem very cheerful does it? Are we really a slave to our DNA? Thankfully, the answer to that question is NO!
Gone are the traditional ideas that the genes we were born with were preprogrammed to express certain characteristics, and we were stuck with this for our lifetime. Now we have a revolutionary new understanding of our genetics – a new branch of science, called Epigenetics.
In its most strictest scientific definition, Epigenetics means “the study of heritable changes in gene function that occur without a change in the underlying DNA sequence”. The term “epi” means above or upon, just like the epidermis is above the dermis layer in our skin. So Epigenetics literally means above or upon genetics, which is fitting given that it is an extra layer of information overlaid on our DNA.
In simple English, the implications of Epigenetics in our lives means that the genes we are born with are by no means the full story in genetically determining who we are, how we look and behave, and which diseases will be set us during our lifetime.
Basically this means that we are not controlled by our DNA… how can this be possible? Well let’s use this scenario to delve further into the depths of what Epigenetics means for us.
So let’s start with our DNA, which is akin to an orchestra; our genes are like the individual instruments in the orchestra. When our genes express themselves (i.e. gene expression) and instruct our cells what to do, it’s like the instruments in an orchestra playing their beautiful melody.
What Epigenetics brings into this dynamic is that our personal environment is like the conductor, controlling and leading the orchestra. The conductor instructs which instruments play at different times, and also directs how they play their music…. Softly or with passion. In just the same way, our environment speaks to our genes, telling them when to switch on or off, and also how strongly or softly to express themselves.
For the duration of our lifetime, our genes are involved in a never ending dance and communication. Some genes will never be switched on and activated, throughout your entire lifetime. Others will be switched on for only an hour or two…. While still others will “express” at different levels of intensity for years. Mind blowing as that is, it gets even more incredible when you realize that it often takes hundreds or thousands of genes acting in supportive, communicative union, to produce a change in our state. In every moment, cascades of genes are undergoing changes in expression in response to our minute by minute experience of life.
The combination of all of these changes in gene expression is part of what is called the Epigenome of a cell. The Epigenome of an eye cell will be very different to the epigenome of a blood cell within our bodies because they will be expressing very different genes (even though they have the same identical set of DNA!). Think of the Epigenome as being like the symphony that is created from all the different instruments (i.e. genes) playing their own melodies.
As we already know, we are born with a set of DNA and genes (our genome) which are pretty much unchanged throughout our lifetime. But what is so interesting is that our Epigenome on the other hand, is dynamic, flexible and ever changing throughout our lifetime, largely in response to cues from our environment!
Just like in the orchestra – the instruments (which are like our genes) always stay the same, but the music they can play and the symphony that is created is dynamic and ever changing, based on the cues from the conductor (i.e. our environment).
And when it comes to changing the symphony played by our own genes, who is the ultimate conductor sending cues to our cells? To a large degree, we are! We are the ones who have personal choice and the ability to create and change the environmental messages our cells and genes receive. What this truly means is that we are no longer the victim of our genetic lottery and inheritance – through the science and understanding of Epigenetics we are able to take personal responsibility for our own health and wellness through choices around the environment and lifestyle that we create for ourselves. We can literally write our own personal symphony of biology, health and well being. Our day to day, moment by moment life choices are able to influence the expression of our genes and subsequently our health and wellness, and even into old age our cells continue to listen for signals and are able to respond accordingly, therefore it is never too late to take control and make a positive change!
