Have you ever wondered how people like Tony Blair or David Cameron, enter the office of Prime Minister looking so fresh faced and optimistic, only to leave a few years later looking old, tired and haggard?
I was fortunate enough to meet Nobel Prize Winner Elizabeth Blackburn and discuss her research with her. Professor Blackburn studies a very specific part of our DNA – an area called the telomere. Her most recent research has focussed on the effect of stress on this part of our DNA.
But firstly, what is a telomere exactly?
Our DNA isn’t just in one big clump in our cells. It’s arranged into 23 pairs of individual strands called chromosomes, and on the end of these chromosomes is the telomere. It acts as a little cap on the tail ends of our DNA to protect it from damage and stop it accidentally unwinding or fraying at the edges.
At the beginning of its life, telomeres are quite long and sturdy. However, scientists have found that every time a cell divides the telomere gets a bit shorter and weaker, and so less able to protect our DNA. As we get older and older our telomeres get shorter and shorter, which makes our DNA more vulnerable to damage. And if our DNA is damaged, our bodies don’t function as well as they should.
When our telomeres get short, our cells notice this and know that they only have a limited number of divisions left before they run out of telomeres. To deal with this, they reduce their activity and only do the bare minimum to keep the cell alive as long as possible. For example, a cell on your scalp might notice its telomeres are getting short and reduce its activity to the bare minimum to keep the cell alive – it might keep producing hair, but that hair might be thinner, weaker and have less pigment in it, making it dull or grey.
This, in a nutshell, is the ageing process. When our telomeres are short and our cells have reduced their activity: injuries don’t heal as quickly, hair and skin cells don’t replenish as well as they used to, our immune systems slow down and our internal organs are more vulnerable to disease.
So, how does stress affect our DNA?
Professor Blackburn’s research shows the dramatic effect of long-term stress on the state of our DNA. She took a group of people who had been caring for a sick spouse or parent for at least 3 years. We’ll call them Group A – The Stress Group. She then created another group of people who were the same in every other respect (age, gender, social background and education) but were not under long-term stress. This is Group B – The Relaxed Group. She then looked at the telomeres of these groups, and the results were striking.
Group A had significantly shorter telomeres than Group B. And remember, the people in each group had matching ages, so this was purely down to the influence of stress and not age. When she looked closer at Group A, she also noticed that the longer the person had been caring for their sick relative, the shorter their telomeres were. So not only does stress affect the length of your telomeres, but the longer you are under stress the shorter they get. In terms of the ageing process, it means your cells get older quicker!
This is part of the answer to the question I posed earlier: why do people in stressful situations tend to look older than they are? One reason is that their cells have shifted down a gear, and aren’t repairing and healing like they used to. The ageing process has been accelerated through stress.
However, it’s not all bad news. Luckily for us Professor Blackburn didn’t leave it there. She sent Group A – The Stress Group, away for a week-long relaxation retreat and looked at their DNA again afterwards. And, would you believe it – their DNA was longer again!
How did that happen?
Come back next week to find out!
Stress has lots of wide reaching implications for our health, even down to our individual cells. When we’re stressed our DNA is less protected, cells are less active and this causes the ageing process to speed up.