No, they can’t. Not exactly, and perhaps not with sufficient precision to be useful to you. But there is a new company called Life Length who will sell you, for the low, low price of £400 a test which predicts when you will die. Sort of.
The test is of your DNA and the length of your telomeres.
Telomeres act like caps on the ends of chromosomes which keep the chromosomes from unwinding or from attaching themselves (chromosomes are gregarious) with neighboring chromosomes. Problem is that the telomeres tend to grow shorter each time the DNA in a cell replicates itself.
Given enough time, the telomere can disappear which is bad news for the cell. The older a person is, the greater the number of times the DNA in cells will replicate. Thus, the length of telomere is correlated with age: long telomeres are associated with youth, short ones with old age.
According to the company’s own press: “The average number of base pairs lost per year varies depending upon both genetic and environmental factors. Eventually, the telomeres shorten to a critical length resulting in chromosomal instability and loss of cell viability.”
Taking this into account, the Independent accurately states:
Scientists do not yet believe they can narrow down the test prediction to calculate the exact number of months and years a person has yet to live, but several studies have indicated that individuals with telomeres that shorter than normal are likely to die younger than those with longer telomeres.
In other words, the best we can do is this: Suppose we have two individuals A and B, both sharing the same birth date. Given only this information, who will live longer? Well, there is a 50% chance that A will outlive B, and a 50% that B will outlive A.
Now suppose we learn that A has shorter telomeres than B, then, ceteris paribus, the chance that B lives longer than A is greater than 50%. How much greater is a wide open question.
First, human lives are never ceteris paribus. A might have telomeres twice as short as B, but might outlive B for a near infinity of reasons. B might become a drunk, or develop cancer, or be hit by a bus, and on and on.
Second, we can’t measure the length of telomeres perfectly. We might say A has shorter telomeres than B, but be mistaken.
Third, we must rely on a statistical model which relates length of life as a function of telomere length. Do we have this model right? Are there others better? Nobody knows.
What we do know is that several studies have shown a positive correlation between length of an organism’s telomeres and number of its remaining days.
But even if the models aren’t that good—even if we can’t do much better than the 50%—the correlation still might have economic usefulness, especially if we must make predictions for thousands of people. Just like insurance companies do.
When you buy life insurance, it is like making a bet you hope you lose. You bet a bookie that you will die this year, and if you do, the bookie must hand over to your survivor some cash. The bookie assesses your odds of living throughout the year and sets the price you pay for the bet.
If the bookie can shade the guess of your odds of dying in the right direction, then he can make a more profit on your bet because he will know to ask you for more money if you have short telomeres. If you have long telomeres, he might not charge you as much (but he probably will).
Perhaps the bookie won’t make a larger profit on your bet considered in isolation, but if can shade the odds for all his clients, he’ll be sitting pretty. So the question is this: how long before life insurance companies require DNA tests from its clients?
Nobody is forcing you to buy life insurance (at least, not yet), so nobody is forcing you to do business with a company which requires DNA tests. The incentive the insurer can offer is a lower rate if you have robust telomeres. But if you had short ones, you would pay a higher fee.
You needn’t rely on the insurer to do the measuring. You can, in advance, contact Life Length and have them measure your telomeres. If they are long, then contact the insurer and save money. If they are long, find another insurer which doesn’t require DNA tests.
But since insurance companies will catch on to this trick pretty quick, they all might require DNA testing. And that will almost certainly lead to yet another sense of unfairness, hence “outrage”, among those poor saps with short telomeres.
Insurers will be called “telomereists”, and the people will demand the government step in and create new rights for the short-telomered. Governments will either ban DNA tests, or require them but mandate the the short-telomered receive a bonus when they die, thus mandating insurers take a known loss.
In other words, no matter what, costs and bureaucracy will increase. Isn’t science great?