The test measures the tip of a person's chromosomes, called telomeres, whose length are believed to reveal the true "biological age" of a person. The shorter the telomere, the short life expectancy and the greater chance of suffering from age-related ailments such as heart disease.

"What is new about this test is that it is very precise,'' investor Maria Blasco of the Spanish National Cancer Research Centre in Madrid told the Independent. "We can detect very small differences in telomere length and it is a very simple and fast technique where many samples can be analysed at the same time. Most importantly, we are able to determine the presence of dangerous telomeres – those that are very short."

Blasco's currently negotiating with diagnostic companies to perform the tests in Spain, and by late this year, in the U.K. But as with all genetic testing, scientists debate the benefits and risks of knowing the potential risks of disease or death years before they might strike. And some worry that such prognosticating tests could be used by insurance companies to deny health or insurance benefits.

There's also the chance that fate will intervene before biology. As one commenter at the Independent observed: "One day your going along planning your life out accordingly. The test tells your you're going to live till 82 so you pull your belt in and start to hoard your money for your retirement. The next minute a bus comes along and bam! It hits you and it's all over for you at 45.

"That's the trouble with living your life by predictions. There are so many variables that could alter the situation in the blink of an eye."

I guess that's where religion come in: helping you plan for the unknowable.