What’s Your Biological Age?

I used to feel young for my age (89). At times, I felt almost guilty about that as I passed other residents in the hallways of our retirement community, walking fast because I was always late and because walking fast felt good. 

Then last fall I caught COVID and had a miserable time with it. Since then, I’ve felt older than my years, thanks to new lower-back problems, arthritis in both feet and the fact that I’m deafer now than I was. I also have less energy. When I first get up in the morning, I sometimes feel more like 99 than 89. I’m hoping that’s not my new biological age. 

Everyone has a biological age as well as a chronological one, because people grow older at different rates. Your biological age reflects the amount of damage that time, environment and lifestyle have done to you, compared to what they’ve done to the average person your age.

These days, websites galore offer tests that will supposedly tell you how old you are biologically. All you have to do is send in a sample of your blood or saliva, for example. I thought about taking one of those tests, but I wondered how accurate they were. 

A webinar focused on biological age promised to answer some of my questions. Organized by the American Federation for Aging Research (AFAR), it offered an interview with senior scientific director, Steven Austad, PhD. I signed up.

The webinar was both disappointing and exciting. It was disappointing because Austad is skeptical about the tests for biological age available online now. The research looks promising, he said, but commercial interests have jumped the gun. (He did describe a couple of low-tech ways to estimate your biological age, and I’ll share those later.) 

What made the webinar exciting was Austad’s description of how those tests may eventually usher in profound changes in the way people age. 

Right now, a dozen or more scientific projects are working to develop a treatment that will make people age more slowly and stay healthy for longer. If one of those projects succeeds, 70 could actually become the new 60.

But as things stand, if the researchers who are trying to put the brakes on aging want to investigate something—a new drug, for example—they must wait years to find out whether they’ve succeeded and their subjects have lived longer, healthier lives. When and if reliable tests become available, scientists can record their subjects’ biological ages before and after therapy and get those results in months—which would vastly speed up the efforts to find ways to slow aging down.

Right now, Austad and others in the field agree that the most promising tests of biological age involve the epigenome, the chemical tags attached to your DNA that turn genes on and off. As you age, there are changes in where those tags are located and how many there are. Scientists have studied the epigenomes of thousands of people and correlated the varying patterns with their chronological ages, health and longevity, and hope to use that data to develop more accurate tests of biological age. 

The research on epigenetics suggests that maintaining a healthy diet and body weight and exercising regularly can help to slow down biological aging. Getting enough sleep is important too. Conversely, smoking, unhealthy eating and a sedentary lifestyle seem to speed up aging.

None of this answered my question about whether my own biological age has increased. With reliable tests not yet commercially available, I was left with the two low-tech methods Austad suggested. 

One of them is to consider your walking speed. By the age of about 50, Austad said, it’s closely correlated with health. I can still walk fast, but I wonder if that counts, since I now do it while pushing a walker. 

Austad’s second method wasn’t much help either. His suggestion: “Ask 10 people on the street to tell you how old you are.” Apparently, many people are really good at gauging age in others. They do it by responding to subtle, complex cues, not just gray hair and wrinkles—which say more about sun damage than they do about age. 

Austad says that by the time most people are 80, they have a pretty good idea of whether they’re young or old for their age. Based on how I feel, I’m guessing that COVID did age me biologically. I’ve decided I’m happier, however, not having my guess confirmed. 

But I like the thought that in the future, my grandchildren may be able to age at a much slower pace than I have and stay healthier for longer, thanks to some treatment yet to be invented.