[Q & A] A new test measuring “biological age” holds out the promise of life-lengthening drugs.
For 500 euros ($700), a company in Spain will tell you how long you’ll live. Well, not exactly – but that hasn’t stopped the media from reporting it that way. What Madrid-based Life Length’s blood test actually does is measure your “biological age,” as indicated by the length of the telomeres at the end of your chromosomes. No medical test can predict the day you will die, but telomere testing does give people an idea of how likely they are to live long – or die soon. The next step in this research will be to develop treatments to stop the degradation of telomeres – which could lead to significantly longer lifespans. In lab mice, an experimental procedure successfully extended life to the equivalent of 120 years.
THE MARK: Tell me about Life Length, and how it developed this test.
STEPHEN J. MATLIN: Life Length was launched by Dr. Maria Blasco in December of last year, and was the culmination of many years of her work in the laboratory. Dr. Blasco works in the Spanish National Cancer Research Centre, where she is one of the world’s leaders in telomere and telomerase studies. Over many years, and with the help of a very substantial team of more than 30 scientists, she developed a technique that allowed her to measure telomeres with unprecedented precision. Telomeres are the protective caps at the end of every chromosome and every part of our DNA, and serve to protect the chromosomal integrity in cell division.
The process of aging is guided by what I’m describing. Imagine the telomere as a kind of plastic cap at the end of a shoelace, which functions to keep the shoelace from unravelling. The telomere “caps” get shorter with each cell division, until they eventually get so short that the cell can no longer divide, and that line of cells dies out. As we get older, an increasing percentage of cells in all our organs and tissues are unable to reproduce, which is why we begin to lose function. Eventually, this progressive loss of telomeres leads to age-related diseases such as Parkinson’s, Alzheimer’s, and cardiovascular disease. These are underlying causes, which are going to be affected by lifestyle and genetics.
THE MARK: Does the test that Dr. Blasco designed actually predict how long a person will live?
MATLIN: It doesn’t predict when someone is going to die, or anything like that. What it allows us to do is get a very good idea of a person’s overall health. It gives us an estimate of a person’s biological age. No one can tell you when you will die, but if someone is 40 years old, and life expectancy is 80, then, statistically, that person has a life expectancy of 40 more years. However, if that person’s biological age is indicative of a 30-year-old, then, statistically, he or she has a life expectancy of 50 more years. In other words, the test is indicative of lifespan, but it’s not predicative of lifespan.
THE MARK: A test that estimates a person’s longevity is certainly interesting, but are there practical applications for it?
MATLIN: The ability to measure telomeres with this precision has a lot of applications for industry, and for the general public, as an indicator of general health. It allows us to make estimates about someone’s biological age, as opposed to chronological age. It also allows for the further application of a trend already established, which is personalized medicine.
There are certain tests for prostate cancer that exist today for men above 40. If a telomere test finds that a man has a biological age that’s significantly lower than his chronological age, that man might decide not to do the test for prostate cancer every year. The inverse could also be true. There might be men who are 35 chronologically, but more like 45 biologically. So health practitioners could begin to alter the medical care they give to individuals by taking these factors into account.
The utility of the test will go well beyond this. An appropriate analogy is the following: When the first cholesterol test came out in the early 1980s, it was expensive. It was a test that was known to indicate a correlation between high cholesterol and cardiovascular disease and heart attacks, but there was no drug – no prescribed medication – that you could take at that time to reduce cholesterol.
People are asking what the utility of the telomere test is. Well, we think a lot of the utility is the knowledge that it gives us, because people can change their lifestyles based on the information that this test gives them. Once the pharmaceutical industry had a marker for cholesterol, it started wondering if it could develop drugs that would target cholesterol in blood. A decade after the first cholesterol test was introduced came the largest class of pharmaceutical drugs in the world, which are called statins – the leading example of which is Lipitor, which has annual sales of $20 billion per year.
We believe a similar thing is going to occur as a result of this new telomere test. It’s going to foster what’s already going on: Scientists and pharmaceutical companies are investigating ways to develop telomerase drugs that will allow us to slow telomere shortening, and thus extend life. We’re not making this up. There are many papers published on this already. There are clinical trials going on. Dr. Blasco has already demonstrated that, by promoting telomerase activity, laboratory mice live the equivalent of 120 human years.
The inverse of this process has applications for cancer. Ninety-five per cent of cancerous tumours have immortality – that is, their cell lines are immortal because their telomerase activity is always on. That’s why tumours grow so quickly. So we are also trying to target the inhibition of telomerase activity.
THE MARK: Can telomere testing predict how likely someone is to develop a particular medical condition?
MATLIN: It’s believed – for example – that short telomeres are indicators of cardiovascular disease. Of course, there are other tests for cardiovascular disease that cost less. But telomere testing may also be indicative or predicative of neurological diseases for which there are no tests. (For instance, there is no test to tell you if you have a higher chance of developing Parkinson’s or Alzheimer’s.) We are going to provide services to companies that want to test these ideas, but we are not in the drug-development business, per se.
THE MARK: A person’s longevity is a sensitive issue. Are you at all concerned about the potential for people’s privacy to be invaded?
MATLIN: Life Length is not going to deal directly with the public. Instead, we are going to receive blood samples. Patients will go to their physicians and get blood drawn, and then the lab company will pick that blood up and send it to us on an anonymous basis. We always work on an anonymous basis because, in order to give good reports, we need a lot of health information on individuals. To respect privacy laws, we always insist on having these tests done anonymously.
THE MARK: Some people have voiced concerns that life- and health-insurance companies will want this sort of data about their customers.
MATLIN: If you want to get a life-insurance policy today, there is a certain point, depending on your age and the amount of coverage you want, when you have to take a physical. So insurance companies are already pre-screening patients; it’s water under the bridge. The insurance industry already evaluates people based on their health, their family history, their pre-existing health conditions, and their job.
As for Life Length, we’re not even remotely close to having this telomere test be so widely accepted that any insurance company would work with it. It needs to become a generally accepted test – used in routine checkups – before insurance companies will consider it a valid source of data. Insurance companies base their assessments on statistics, so they would need large amounts of statistical data on this test.
THE MARK: Do you envision a time when this telomere test will be a regular part of a medical evaluation?
MATLIN: Absolutely. And it will, as you say, be a part – just as medical professionals look at your cholesterol regardless of whether you’re overweight, and regardless of whether your parents died from cardiovascular disease or cancer. They look at many, many factors.
THE MARK: When will this test be available for doctors to order?
MATLIN: We are trialing it now. We also want people to be educated about the test results, so it has to go through physicians. To get to hundreds of thousands of physicians globally, we need to work through companies that have that kind of access – which is why we are looking to work with lab companies.
We are gratified to see there’s an interest in trying to understand something that is complex scientifically. This is cutting-edge technology, so it’s appropriate that people ask hard questions and show some skepticism toward it.