It’s not perfect, but scientists are excited by the potential
Predicting death was once just a trick for fortune-tellers, with nothing scientific about it. But now, scientists are getting a little bit closer to being able to forecast when your time might run out.
Though predicting an exact day is far from likely, an experimental blood test may be able to tell an individual’s risk of dying in the next five to 10 years.
Researchers in Europe made a predictive tool using data from more than 44,000 individuals ages 18 through 109 years old, 5,500 of whom died during the study period. They identified 14 different substances from participants’ blood samples that were associated with a risk of death — such as blood sugar, lipid particles that transport “bad” cholesterol throughout the body, and albumin, a protein made by the liver that keeps fluid in your bloodstream so it doesn’t leak into tissues. When these substances get higher or lower, they can be indicative of certain health problems, like Type 2 diabetes or cardiovascular disease.
Using those 14 indicators, the researchers built a model that predicts the likelihood that a person will die in five to 10 years. In a new study published Tuesday in Nature Communications, they report the prediction accuracy was around 83% overall. For individuals over 60, the accuracy fell to about 72%.
One problem with the predictor, however, is that the data came exclusively from people of European descent, so it wouldn’t be able to accurately predict mortality risk in people of Asian or African descent, for example.
But even if a test could predict when you’d die, researchers say you’re not bound to your fate. Joris Deelen, a postdoctoral researcher at the Max Planck Institute for the Biology of Ageing in Germany and an author on the new paper, says people could still change their lifestyle, which would change the mortality risk prediction.
“This is an exciting study,” says Daniel Belsky, an assistant professor of epidemiology at Columbia University who studies aging and was not involved with creating the new predictor. He says the test could be especially helpful for evaluating risk in individuals who do not yet show signs of poor health. “Such measures are needed to test preventive interventions that aim to delay onset of aging-related disease. These interventions may be most effective when delivered by midlife.”
The test says something about how far down the road a person has traveled, but not how fast they are driving.
These measures could include adjusting one’s diet, starting an exercise regimen, or taking certain medications. But they could also extend to things like economic assistance programs, social and community engagement, or a person’s housing, neighborhood, or work environment — which all have an impact on someone’s life expectancy.
Dr. Eric Verdin, a physician-scientist and CEO of the Buck Institute for Research on Aging in Novato, California, says researchers are becoming very interested in the idea of predictive tests because they could help evaluate new drugs designed to extend a person’s lifespan.
“Until a few years ago, people thought aging was a variable you could not change,” says Verdin, who was also not involved with the study. But the science of aging has evolved. Some researchers have started to see aging as a disease that can be treated, and a number of labs are developing drugs with the hope of altering the rate of aging.
“We have a number of drugs that are slowly entering the clinic with the very specific aim of slowing down aging,” Verdin says. “The problem is, how do you measure this?” That’s where a mortality predictor comes in handy. It’s not practical to follow people for 20 or 30 years in a clinical trial. But if you could see whether a drug is having an effect on the aging process in a shorter time frame, that would be a boon to drug developers. For instance, you could test someone’s mortality risk at the beginning of a study and at specific points throughout a study, such as every six months, to see if that risk score goes up, down, or stays the same.
Eventually, middle-aged and elderly people might get a death predictor test at a routine checkup or when they’re hospitalized to help doctors guide treatment and recommend preventive measures.
Other scientists are working on so-called aging clocks, which estimate a person’s biological age, or how old a person seems based on their health. Among aging researchers, there’s an idea that people have a chronological age — that is, the number of years they’ve actually lived — and a biological one. You might be 30 years old with the biological age of a 50-year-old because of an underlying health condition or total lack of exercise, for example. The hope is that you might be able to take steps to sync up those two numbers, either by taking a drug or doing something else.
Steve Horvath, a biostatistician at the University of California, Los Angeles, has developed perhaps the most well-known aging clock — the latest version of which is dubbed GrimAge — to predict when a person might die. Horvath’s test looks at a process in a person’s DNA called methylation, a process that Horvath likens to rust, which has the ability to switch genes on and off. Verdin says it’s likely that researchers will need to use a combination of different tests to get the best possible prediction.
And the new predictor will need to be tested to see how it changes over time for individuals as they grow older, says senior study author P. Eline Slagboom, an aging researcher at Leiden University Medical Center in the Netherlands. That means researchers would need to follow people over time and use the test on them again and again. The new study only looked at previously collected data in other studies.
“The current study tells us that this new [tool] can measure how much a person has aged up to a point in time,” Belsky says. “Ultimately, the measurement we need most is one that tells us how fast a person is aging across multiple time points.”
In other words, the test says something about how far down the road a person has traveled, but not how fast they are driving. To test if a drug or some other intervention, such as diet or exercise, can slow aging and extend healthy lifespan, scientists need to know both things. So don’t worry: You probably won’t be able to get a death prediction at your doctor’s office anytime soon.
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