Blood test that can predict our longevity will be a powerful tool in shaping savings policy

Alf was alerted to a Spanish company’s announcement that it can help determine when people will die by using a blood sample, a US$700 test, and research that earned three American geneticists the Nobel Prize in medicine in 2009.

The tip-off came from a Freakonomics post which raises very important political issues.

For example, if governments obliged citizens to take such tests to find out how long each of us will live, they will have a powerful tool for dealing with the savings problem.

As happens in this country, pervasive under-saving among American households is a consequence of the fact we don’t know how long our savings need to last.

Save too much and you miss out on having fun when you’re alive. Save too little and you end up broke and reliant on the social safety net that taxpayers fund.

But let’s not jump the gun.

We are not there yet, and the emphasis in that first sentence should be on the words “can help determine”, because…

Though the test has its critics, and though it won’t offer an exact date for one’s death, it does promise to reduce uncertainty about longevity by examining a tiny part of DNA that reveals biological age as opposed to chronological age.

Successive generations of the test are likely to improve in predictive power.

Freakonomics will steer you to an ABC report which says the test “could potentially offer some proof that many people really are older than they look”.

The test measures the length of a person’s telomeres, the pieces of DNA at the ends of chromosomes.

As cells keep dividing with age, the telomeres get shorter and shorter. By measuring telomeres, some scientists believe they can determine biological age, which doesn’t always equal chronological age.

“That means some people may be biologically older or younger than their age,” said Jerry Shay, professor and vice chairman of cell biology at UT Southwestern Medical Center in Dallas. Shay is also on the scientific advisory board of Life Length, the manufacturer of the test about to be sold in the United Kingdom. “The test will tell you within about a decade what your biological age is.”

Then came the disappointing bit.

Shay stressed that although the test is an indicator of biological age and is possibly a factor in determining life span, it cannot definitively predict how long a person will live.

This was blindingly obvious to Alf, actually.

The test can’t do a damned thing about warning you will become an earthquake victim, or a car accident victim, or choke to death in an aircraft, or whatever.

More to the point of these telomere things, however, they are rough rule-of-thumb indicators.

“If you have really short telomeres, that doesn’t mean you’re going to die in the next year or two,” Shay said. “It’s really for the average person who’s just curious his or her general health.”

He also said people who may be concerned about disease in their family may also be interested to know about how quickly their bodies are aging.

That naturally raised questions about the worth of the tests.

On the one hand, obviously it can provide people with valuable information that can encourage them to adopt healthier lifestyles.

“If your telomeres are much shorter than most people your age, that could be a red flag that perhaps you need to do something to try and reverse the conditions that led to that,” said Shay, such as adopting a healthier lifestyle.

But others say it is a waste of money.

Dr James Evans, editor-in-chief of Genetics in Medicine, the journal of the American College of Medical Genetics, reckons you don’t need a 500 euro test to tell you that you need to exercise and eat right.

Moreover the results may not be very useful to most people because many factors affect longevity.

“Research has shown that lifespan is determined by both genetic and environmental factors and therefore a test examining one measurement, may not accurately predict this process,” said Heidi Tissenbaum, an associate professor at the University of Massachusetts Medical School.

“More research is needed to show the connections between telomere length and a person’s life span.”

But Steve Sexton at Freakonomics has focussed on the potential of the test to become more predictive, and the political implications of this scientific triumph.

An individual’s longevity is the source of a number of problems, he points out.

Many of them are personal, but some have implications for society writ large, and taxpayers in particular. So one wonders: if the government can make you confront the calorie content of your diet, can it also make you confront your mortality?

If the government were to mandate “life length” testing, it could help resolve the intractable lifetime savings problem.

Under-saving burdens society much like obesity among the uninsured, he says.

And ignorance about how long we will live can only cause a drain on the Treasury.

Resolving uncertainty about longevity therefore would be in the interest of society and in the interest of strictly rational individuals, who, armed with the knowledge of when they will die, could make optimal savings decisions and check off all the items on their bucket lists.

And yet, Sexton reckons, a great many of us would choose not to undergo the testing even if it were free.

That’s because we simply don’t want to know when we will die.

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