A new blood test that’s about to hit the market claims it can show how fast a person is aging – and estimate how much longer a person has to live.

The test, developed by the company Life Length, supposedly reveals a person’s “biological age” by measuring the vital structures on the tips of a person’s chromosomes, called telomeres. It will be offered to the British public later this year for about $700.

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I urge consumers not to waste their money on this so-called medical breakthrough. In my honest opinion, this test is utter garbage that has no use in clinical medicine.

The developers of the blood test say that your lifespan depends on how long your telomeres are. The shorter the telomere, the shorter the lifespan.

I’m here to tell you that this is simply untrue. Whether you have a short or long telomere almost never directly translates to how many years you are going to live.

What actually matters is your lifestyle – whether or not you follow a proper diet, get enough exercise, and refrain from smoking and other risky habits. Those are the keys to living a long, healthy life – not chromosomal structures in the body that you ultimately have no control over.

As far as I’m concerned, the claims the developers of this test are making are incredibly irresponsible – even dangerous. If anything, people who are told they have long telomeres may actually die sooner because they may believe that they don’t have to work as hard to stay healthy and fit in order to live longer.

This attitude can also result in a number of health-related consequences, such as obesity, diabetes and other lifestyle-related diseases. There isn’t so much appeal in living longer if those extra 20 years are riddled with illness and hospital visits, is there?

The bottom line is that you can’t change what your telomeres allegedly reveal about your lifespan. What you can change is how you shape your health. My recommendation is simply to stay healthy – live healthy – in order to have a longer, better quality of life.

Dr. Manny Alvarez serves as Fox News Channel's senior managing health editor. He also serves as chairman of the department of obstetrics/gynecology and reproductive science at Hackensack University Medical Center in New Jersey. Click here for more information on Dr. Manny's work with Hackensack University Medical Center. Visit AskDrManny.com for more.