New blood test could reveal how fast you're aging

After driving my housemate to the shop today, I decided to kill time while she shopped by picking up something to read. Normally I head straight for New Scientist or Scientific American, but today I was drawn toward the newspapers; more specifically The Independent. Why, you may ask? Well a certain article caught my eye.

"It works on birds - so could a simple blood test tell you when you're going to die?" A simple but effective title, playing off today's obsessions with youth and longevity. However, this one isn't some phony cream or miracle face wipes, but rather a scientific study.

This article stood out to me in particular because I nearly did my dissertation on the very thing it is using as a test subject: telomeres. For those who don't know; telomeres are structures on the tip of your chromosomes (your genes) composed of a repeating sequence of base pairs (the "language" of DNA). They protect the actual important DNA from damage and they get gradually shorter with age. They go through a sort of "wearing down" process, when a cell divides they become slightly shorter, and those with shorter telomeres tend to suffer premature aging and related diseases. In this sense they act sort of like a biological clock.

Chromosomes with telomeres highlighted in red

Of course,  this wasn't the part that captured my attention. The article describes researchers testing telomere length on a population of 320 island birds. Island birds were important to use, as they have little/no migration and no natural predators, so the gene pool stays relatively stable. The researchers found that if the birds had telomeres that were becoming shorter at a faster rate, it indicated they would die within a year. They also found that birds with longer telomeres had a longer life span. 

This changes the way telomeres are viewed, it was thought that they shortened at a constant rate, but these researchers found that individuals suffer different rates of shortening depending on the levels of stress and exertion in their lives. Their results also provided the first clear, unambiguous  evidence of a link between telomere length and mortality in the wild, and that telomere length and shortening rate can be used to predict biological age.

People are beginning to capitalise on this, despite the fact that the science behind it is still rather young, causing a lot of controversy and ruckus. One company is offering a £400 blood test to determine how fast you are aging based on your telomere length.

The question this whole thing raises to me is whether it's actually beneficial to know your lifespan? I don't know about you guys but I like life to be a surprise. Obviously certain genetic tests are beneficial, to determine your susceptibility to certain diseases (ie cancer, diabetes) and make lifestyle changes to avoid these. But knowing how fast your body is aging doesn't seem all that beneficial. Of course, it should be made clear to those that do take these tests (assuming they are scientifically robust and accurate)  is that it's based on probability and likelihood, not clairvoyance, and although you may be aging slowly that's no reason to make bad lifestyle choices.

Would you take this test? What are your feelings on this whole subject? Comment with your views!