Lifestyle: The truth about telomeres

The question ‘Does size matter?' has plagued both men and women for centuries. The conundrum is generally resolved with a quick-fire cliché, usually to the tune of ‘It's what you do with it that counts'.

Following new research, however, scientists at Glasgow University have found evidence that an individual's length can make a difference to their well-being, proving once and for all that size does indeed matter. So, how long are your telomeres?

A telomere is found at the end of a chromosome and protects cells from damage, rather like the plastic end of a shoelace. Led by Pat Monaghan, the Glasgow team confirmed a connection between telomere length and life-expectancy, proving that some aspect of biological age is written into DNA from birth.

Conducted on a group of zebra finches, the experiment measured the telomere length of 99 individuals when they were 25 days old. “What hasn’t been done before was to follow the same individuals through their lives,” explains Monaghan.

The benefit of monitoring the birds from an early age was that Monaghan could analyse their unaffected lifestyle potential. Not factoring in accidental death, disease and predators, in every case the pattern was clear. The longer the telomere, the longer the life

Good news for the genetically well-endowed zebra finch then, but what does this mean for us? Monaghan says that interest in her research is understandably intense. “The idea that there might be a biological clock inside us that's ticking and there's nothing you can do about it is what people are really interested in. It looks like their biological clocks are ticking at the same rate, yet the outcome's different.”

So what if we could predict when the batteries will die in our biological clocks? This study appears to prove that at least some aspect of life-expectancy is written into genetic coding, an idea that would impact enormously on the way we live our lives.

While Glasgow has been confining its research to birds, in Spain the company Life Length is offering telomere measurement for human beings. The expensive and controversial treatment (it costs around ¤500) takes a blood sample and uses it to estimate a person’s biological age by measuring the percentage of short telomeres.

The company claims that knowing the length of your telomeres gives you the opportunity to change your lifestyle, the suggestion being that finding out you have a short telomere length should be like finding out you have high cholesterol – it is bad for your well-being and should be remedied.

Experts believe factors such as high stress, smoking and obesity all significantly reduce telomere length. But surely, even without a controversial blood test, such lifestyle advice shouldn't come as a surprise? We may not have been aware of the intricate little shoelace caps protecting our precious DNA, but few of us can be ignorant of the fact that smoking, stress and obesity are bad for you.

Though this might seem a ground-breaking revelation, in many ways we would be no more protected from an early death if we did find out what our expected lifespan was. No matter how long telomeres might be, we are still vulnerable to disease, we are still affected by the environment and we are certainly not protected from life-threatening accidents. This area of science is as intriguing as it is controversial, and raises philosophical as well as medical issues. How much of our lifespan is written into our DNA, and how much is left to fate?

Life-expectancy in Scotland is 76.3 years for the average male and 80.7 for the average female born in 2010. It is currently the lowest in Europe, and the subject of an ongoing government campaign to make Scotland healthier.

The figures are based on the health and lifestyle of the population as a whole, and don't take into account factors affecting each individual. A person living in the most deprived area of Scotland, for example, is expected to live on average 18 years less than their wealthier counterpart, proving that an average life-expectancy statistic is not as reliable as a personal indicator would be.

So what would someone do, armed with knowledge of their life-expectancy? Telling a teenage boy he has a short telomere might be enough to kick-start a positive change. However, knowing when your body will close for business could also be potentially harmful. If the average male believes that by maintaining his lifestyle he would live to the ripe old age of 76.3, there is little incentive to make positive changes. “It would be interesting,” says Monaghan, “if people knew what their lifespan potential was, would they become more reckless?”

Finding out that your telomeres are in tip-top shape could encourage people to stop worrying about their health, to have that extra drink or to swap the salad for chips. Conversely, we could nurture a generation of hypochondriacs that are so hell-bent on preserving their telomeres that any enjoyment is taken out of their longer life. Some people, if told their expected span was shorter than average, could become nihilistic fatalists.

An individual's reaction is as unique as their genetic make-up. For Monaghan, her own biological age is something she wouldn't want to know. “It would totally change your attitude to your life”, she says. While her research partner, Neil Metcalfe, believes “it would alter everything I did, I'd always be counting down to that day”.

Though it seems the researchers would rather be left in the dark, there is always the temptation that knowing when your time is up would motivate a positive lifestyle change. “It depends, doesn’t it?” says Monaghan.

“Some people take the attitude, ‘Well, I might as well enjoy myself while I'm here and I don’t care what happens with me.’”

Whether you measure longevity in telomeres or time, one solid argument to come out of this research is that the healthier you are, the better your chances of a longer life. With studies into longevity being continually developed, there may be more information about our own death dates in the future, all of which poses a question for every one of us – would you want to know?

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