Learning My Biological Age Changed The Way I Think About My Health

“Am I going to die early?” I say out loud for the first time in my life. I’m not in a doctor’s office or a hospital — I’m on Zoom with a scientist. And I haven’t been diagnosed with a serious condition or been in a fatal accident, and there’s no known reason why I’d be prone to an early death. But I had just received an email with my supposed biological age after taking a test fom Tally Health. It was alarming to see that I was, apparently, years older than my chronological age of 26.

When we think about age, our minds likely go to the number of candles on our birthday cake. But scientists, longevity enthusiasts, and even doctors have argued that our biological age is a more important number to look at when it comes to how well our bodies are working — not how old we actually are.

“Biological age is this idea of, how am I ageing internally?” says Adiv Johnson, PhD, director of research and innovation at Tally Health, a biotechnology company that focuses on biological ageing, while we’re on Zoom. “If you look at two people who are both chronologically 70, but one person can hike up a mountain or run a marathon and the other person is struggling to do day-to-day tasks, you quickly realise they’re ageing in very different ways. That’s where the idea of biological age comes in — it helps explain why people with the same birthday age so differently.” Ideally, your biological age would either be the same as your chronological age or younger — not older, like mine unfortunately turned out to be. This means that, internally, my cells and my DNA and the functions of my body aren’t working as a “normal” 26-year-old’s should be (and likely to no one’s fault but my own).

And no, Dr. Johnson assured me, that did not mean that I was going to die early. It’s not the number of years we live, but the quality of those years that proponents of biological age are most interested in. For Guru Banavar, chief technology officer at Viome, another biotechnology company, there’s a clear distinction between lifespan and healthspan. “For example, somebody may have lived up to 95 years, but maybe the last 20 years of their life were miserable,” he says. “What we'd like to do is to find the longest possible healthspan for each individual. If you're going to live until 95, you want to be healthy until 95.”

There are many, many ways one can have their biological age calculated, according to Banavar. “There are people who measure it using your DNA or using a methylation, they may measure your heart health, they may measure your brain health, they may measure your gut health. You can measure all kinds of different things in different parts of your body,” he says. “At Viome, we do biological age relative to your gut microbiome.” Viome’s test takes into account three different samples: your saliva, your stool, and your blood. Tally Health, on the other hand, examines DNA methylation which is how your genes are expressed, and has a far more simple test that consists just a cheek swab. Elysium, another company that tests biological age, also examines DNA methylation and tests saliva samples.

To know your biological age, a test — like ones from the brands mentioned prior — is necessary. “It’s really hard to change what you can't measure,” says Trinna Cuellar, PhD, vice president of biology and head of research and development at Tally Health. “What we're giving people is a tool to be able to begin to assess how they are ageing.” It’s important to note that your biological age isn’t final, either — it’s a snapshot of how you’re ageing at the specific time you took the test. And unlike your chronological age, your biological age can ebb and flow. For example, if I decided to adopt healthier habits — such as prioritising better sleep, exercising more often, eating better, drinking less alcohol, etc — and I re-took that same biological age test weeks or months later, it’s likely that my number would be lower.

If I took another test from another brand, my biological age may be different, too. “Each such test is likely measuring the biological age of a specific aspect of your biology, such as your human DNA age, or particular organ based age, like heart age and so on,” says Banavar. “These specific aspects of your biology may indeed vary in how they age within a single individual.”

For these scientists, the primary goal of making this information accessible is to promote healthy aging. “We have really powerful data indicating that if people on the whole make changes — like adopt a Mediterranean diet or do more strength training or cardio — their health outcomes are much better in not only life expectancy but how healthy that life expectancy is,” says Dr. Johnson.

So, is knowing your biological age a necessity in leading a healthy life? Not exactly — most of these tests cost hundreds of dollars, and they’re meant to be taken multiple times to check in on the status of your ageing cells. But those in the field hope to one day lower the costs of these tests to make them more accessible for all. “I really do think that it should be available to everybody in the world,” Banavar says. “And for that, we have to bring the cost down, we have to increase the scale, and so forth.”

Dr. Johnson says that this technology was created in 2013, so we’re only a decade into learning all that it can do for us. But still, having as much information as possible about your health and wellbeing — and, okay, maybe age — is incredibly valuable. Although scientists and doctors may disagree on the exact hallmarks that make you biologically younger, they all seem to agree on the basics: a balanced diet, consistent exercise, enough sunlight, good quality sleep, less stress, less alcohol, more vegetables. I’ve promised myself I’d give those a harder try —  if all goes well, then maybe my next biological age test won’t send me into a frenzy.