"You're only as young as you feel" is a phrase that we hear tossed around all the time. But, what if it's actually true? Morgan Levine, a researcher and professor at Yale's Medical School spends a lot of time calculating just how true that statement actually is. Turns out, it's truer than we'd believe. Basically, every person does in fact have two ages: their chronological age, which is the age you are according to your calendar birth date. But then, there's the phenotypic, or biological age, the age at which your body functions compared to average fitness or health levels.
These two differences in age explain a lot really. Two people can be the same calendar age, and yet, so different physically. So even though you're both, say, 32, one of you may actually be 22 biologically, while the other is 72.
According to professor David Sinclair, co-director of the Paul F. Glenn Center for the Biology of Aging at Harvard Medical School, chronological age doesn't really mean much of anything when it comes to determining age. He claims that it's really just a superficial number. Basically, what that means is the age you turn on your birthday is merely the amount of years you've existed, but not truly how old you are.
"We all age biologically at different rates according to our genes, what we eat, how much we exercise and what environmental toxins we are exposed to. Biological age is what determines our health and ultimately our lifespan," he tells CNN.
As a part of her research, Levine have identified nine biomarkers from blood test samples to determine biological age. Those biomarkers include kidney and liver measures, blood sugar levels and immune and inflammatory measures. The biomarkers are indicators of what is most influential to your life span.
Obviously, those who have a biological age that is lower than their chronological age have lower risk of mortality. Those who present as biologically older, in addition to having higher mortality risks, are also potentially more as risk for diseases associated with that advanced biological age.
But, the good thing about biological age is that, unlike chronological age, it can be changed. Because the biomarkers are more often than not tied to body function, change in things like diet can make a difference. Exercise, better sleep habits and other small tweaks in your lifestyle can have an impact on your biological age. Unfortunately, you'll just have to grapple with getting chronologically older.
"We actually know a lot about how to change some of these markers. I think we are given the information much earlier in the process, hopefully before someone ever develops disease, and then they can really take steps to improve their health before its too late," Levine also tells CNN.
So, maybe you are really as old as you feel.