Described as the holy grail of ovarian cancer research, the test can detect the disease in the early stages when it is easiest to treat.

London - In Greek mythology, Lachesis, one of the three Fates - ageless women who spun the thread of life - had the job of taking a measuring stick and determining the length of each mortal's life. Now in the 21st century we have a company called Life Length that claims to have found a way to do almost exactly the same. It hopes to make a fair bit of money out of it, too.

Not long ago I had never heard of telomeres, the tiny structures on the end of our DNA, the length of which shows us how fast we are ageing - or so the people at Life Length say.

When the science editor of The Independent began looking into the subject, he sought a volunteer to take the test and I was happy to oblige. Perhaps as one of the younger people in the newsroom I felt less anxiety about what the test might reveal.

Now I am one of the hundred or so Britons to have taken the Life Length test. It is very straightforward. They draw some blood (only three phials - much less than a standard blood donation) and you complete a short questionnaire with questions about your health, lifestyle and the longevity of your direct ancestors.

The results do not come in the form of a specified age at which you will die (Life Length is not quite as blunt as that) but rather as a “biological age” distinct from your “chronological age”.

The outcome? I now know that though my birth certificate says I am 24 years old, in my bones I am really 29 - and so five years closer to shuffling off this mortal coil than I had thought.

Losing five years in a flash is rather disconcerting. Colleagues gathered round to console me as the results dropped into my email inbox. Five years: that's five Christmases, five springs, five FA Cup finals - gone!

But I am not taking the results too seriously. If I were a real Life Length client, rather than a guinea pig, I would show my results to my GP, who would advise me to cut back on drinking and smoking, eat more healthily and do more exercise. Doctors have been telling people that for years. I can't see why anyone would need to spend £650 (about R8 900) to be told again.

My report also contained a series of graphs comparing my biological age to the average for my age group. Life Length suggests that people take the test at least once a year - presumably so you can watch your biological age go up and down on the graph as your health improves or deteriorates - like a roadworthy of your own mortality.

The thought that, rather than enjoying their lives, people will be spending hundreds of pounds to find out how fast they are ageing, and probably losing sleep over the thought of how many years they might have left, is a sad one.

The whole concept reminds me of the kind of private health companies that will prescribe patients dozens of expensive tests for diseases they probably don't have.

I'm quite happy to leave the thread of my life in the capable hands of the Fates. - The Independent