Have you ever really thought about why we age? Why do we turn grey and frail? Why don’t we just look the same as we do when we are in our 20s? Is it in our genes? Are we just programmed that way? Well, according to Harvard researcher David Sinclair (named by Time magazine as one of the most influential people in the world) we are not programmed that way and he claims an ‘aging gene’ will never be found. In his fascinating book ‘LifeSpan’ David shares his theory on aging..and it goes something like this….
We age because the cells in our body lose information. What information? Not the genetic code. DNA is ‘digital’ information in that there can only be a finite number of values based on a the 4 bases A, T, C, G. This information can be copied without loss and every cell in the body has the same DNA.
The information that is lost is from something called the epigenome. Information in the epigenome is heritable but can be lost along the way. Unlike digital, some analog information is lost when it is copied, which is one of the reasons we moved from cassettes to CDs.
But what is this epigenone? In broad terms, this is the dynamic structure that ensures a cell becomes a skin cell, and STAYS a skin cell (or becomes a hair cell, or a brain cell etc). Every cell has the same DNA, but what makes them different is the epigenome. The epigenome does this by controlling which genes (sections of DNA) to turn on, and which to turn off (gene silencing).
Over time, the epigenome will stop silencing certain genes that are meant to be turned off. This is is ultimately why our skin wrinkles, our eyesight fails and our bones weaken. It’s why we age.
But why does the epigenome stop silencing these genes? Well it turns out that some key proteins that silence the genes have another purpose. This purpose is to fix damage in the cell when things go wrong. The problem is, they can’t do both at the same time. So, if they are constantly repairing damage caused by poor diet, pollution and UV damage etc, they are not silencing genes and therefore our cells are not behaving as they should. What’s worse, if they are away from the DNA too long, they can’t find their way back…which is ultimately what will happen.
But there is hope! In part two, I will explain what we can do to mitigate this now, and what the future may hold for us..