If you’ve ever been to a high school reunion, you know that some people seem to move faster than others. Twenty-five years after graduation, one classmate may appear ten years younger than the other, another ten years older.
“People know this intuitively, but they don’t understand that what we’re trying to find is biology,” said Dr. Nir Barzilai, director of the Geriatrics Research Institute at the Albert Einstein College of Medicine.
Scientists are working to measure this phenomenon and calculate the number by looking at the health of their cells, not the number of years they’ve lived in a person’s “biological age.” Some of these parameters are marketed as direct-to-consumer blood tests. But before you spend hundreds of dollars to find out how old you are Really are, make sure you know what you’re paying for. While these tests can be interesting and useful research tools in theory, experts caution that they are not ready for prime time.
How do you measure biological age?
Researchers define biological age as “the accumulation of damage we measure in our bodies,” says Dr. Andrea Britta Mayer, director of the Center for Healthy Longevity at the National University of Singapore. That damage comes from natural aging as well as our environment and behavior.
The concept is often attributed to the British physician-scientist Dr. Alex Comfort (probably best known for writing “Sexual Pleasure”). 1969 paper On the idea. But for decades, scientists didn’t know how to measure a person’s biological age.
A breakthrough came in 2013, according to Steve Horvath, professor of human genetics and biostatistics at the University of California, Los Angeles. He suggested using “clock”. Based on the field of epigenetics. Throughout our lives, DNA undergoes molecular changes that turn various genes on and off. Dr. Horvath analyzed these changes in thousands of people and developed an algorithm to determine how they correlate with age.
These changes occur naturally as we age, says Jesse Poganik, a professor at Harvard Medical School who studies biological aging. They can be spread by behaviors that affect health, such as smoking and drinking too much alcohol. As a result, the estimation of biological age is related to factors such as life expectancy and health, he said.
Why you should be careful of consumer temptations
Several companies sell tests for around $300 that use this technology to calculate your biological age by analyzing your blood or saliva and comparing changes in your epigenome to the population average.
But experts caution that epigenetic clocks can’t tell you much about your own health. Because they are designed to evaluate large groups of people, not individuals. As a result, their results can be unbelievable.
At a recent conference where Dr. Horvath spoke on the subject, an audience member said he took two different tests and got two different ages, 10 years apart. Dr. Horvath said the man should have saved the money.
“I think you could say that the best of them are not completely useless,” said Daniel Belsky, an associate professor of epidemiology at Columbia University. He created an epigenetic clock himself. But these aren’t tried and tested clinical tools yet, so they’re more for curiosity.
Another problem with testing is not knowing what to do with the results. Scientists don’t know how to reverse a person’s biological age — or whether it’s even possible.
In part, this is why epigenetic clocks were developed in the first place. Researchers hope to use them in clinical trials for anti-aging interventions to measure potential changes in the lifespan of hundreds or thousands of people at a time.
None of this has stopped companies from selling these tests along with personalized health and lifestyle recommendations, in addition to supplements that will restore an individual’s biological age.
Putting a new spin on old information
Epigenetic clocks are not the only products on the market that promise to measure biological age. Some companies offer a panel of common blood tests that you can get at a doctor’s office, such as cholesterol or hemoglobin A1C, a marker for diabetes. Many of these numbers increase as we age, so they can serve as a proxy for a person’s biological age, they say. For example, if you are 45 years old but your cholesterol levels look like those of an average 50-year-old, the test results may indicate that you are biologically older than 45.
Whether blood marker tests accurately track biological age as opposed to general health is debatable. But the benefit of this type of test is that it measures things that can be improved; We know how to lower blood sugar levels with medication and lifestyle changes, for example. In contrast, epigenetic age is now much more than a black box.
“Expanding access and using repeated trials to improve health seems logical to me,” Dr. Poganic said in an email. However, he added, “any claims of accurate, individual biological age determinations should be approached with caution.”