Many factors can affect how long our telomeres are, some of them inherited and some due to our lifestyle and environment. Across the population there is a considerable range of normal telomere length – but one thing that will happen to all of us is that our telomeres will shorten as we age.
There is now compelling evidence that the shorter one's telomeres are, the greater the chances that we will suffer from some of the more serious age-related problems such as heart disease and pulmonary fibrosis.
So how helpful will it be for us to know our individual telomere length? I've measured my telomeres and know that they're a bit short for my age. Does that bother me? Not at all, because I'm happy to sit within the normal range and do not appear to be aging prematurely. Although it has been suggested that people who have shorter telomeres and are at risk of heart disease might benefit the most from taking cholesterol-reducing statins. One thing that might interest me more would be to know how fast my telomeres are shortening. If they're rapidly decreasing, then perhaps I might be a bit concerned. And that could be good news for the companies who hope to make money by measuring our telomeres, as they could say that repeat testing is the way to go.
Some people have exceptionally short telomeres due to a rare inherited condition resulting in bone marrow failure. In this situation, we are measuring telomere lengths as they can be helpful in diagnosis and making sure that these patients get the right treatment.
But in the normal population, what would we do with the knowledge that our telomeres are short, or shortening more rapidly than normal? Give up smoking? Cut back on the amount of alcohol we drink? It's not difficult to believe that regular exercise and a low-fat diet would be good for most of us, whatever our telomere lengths.
As scientists uncover more about the things that influence the rate at which we age there will be a multitude of predictive tests that could become available. The problem is that each one is likely to contribute one piece of the jigsaw in the complex process of disease-susceptibility.
So when all is said and done, I still believe that a good knowledge of our extended family's recent medical history might be as good as any current laboratory test in predicting how well we're going to live on into our old age.
The writer is a senior lecturer at The Blizard Institute, Queen Mary, University of London