Women with JuvYou Healthy Aging app on her phone

Can an Algorithm Predict Your Biological Age?

How old are you? It seems like an easy question. But there’s another answer besides how many times you’ve been along for the Earth’s ride around the sun. And this one is a whole lot better at telling you something about yourself than merely the vanishing of another 365 days.

Chronological age, the number of years that have elapsed since a person’s birthday, offers a measurement of the passage of time. It’s the same for everyone—one person who has lived 50 years gets the same number of candles on their cake as anyone else who has lived that long. It doesn’t give any indication of a person’s health at that moment or any useful predictive power for the quality of the years that person has left.

Chronological age:
A person’s age as measured from birth to any given date. The number of years a person has been alive.

But a much smarter number tells more of a person’s story. It’s called biological age. This more complex metric may include a spectrum of personal details that can quantify aging-related processes and health relative to a reference population. This information can provide insights into an individual’s wellness today and how to live a longer, healthier life tomorrow.

Biological age:
A number derived from measuring and analyzing personal genetic, health and lifestyle indicators to indicate an individual’s health profile relative to the rest of the population.

The difference between the same person’s biological and chronological age can be stark, says Dr. Josh Anthony, PhD, a cellular and molecular physiologist who works at the intersection of health, nutrition and personal wellness. To better understand the contrasting ideas, he suggests thinking of a pair of vehicles.

“Imagine you’ve got two cars that are the same number of years old. That’s their chronological age,” Dr. Anthony says. “But one car was driven hard for 100,000 miles, and the other spent its time in a garage and only has 10,000 miles. It’s a matter of wear for the two cars, and the difference in mileage—the difference in wear versus care—is like biological age for humans.”

A more nuanced measure

Biological age takes into account a host of factors specific to the individual. These can include inherited components in DNA; epigenetic factors; blood biomarkers like lipids, glucose and measures of insulin sensitivity; markers of inflammation and nutrition; blood pressure and heart rate; and indicators of inflammation and DNA damage. Other aspects like environmental factors, family history, dietary and exercise patterns, and sleep quality can move a person’s biological age up or down.

“It's about your genes and the lifestyle choices that change how those genes are expressed. We know lifestyle choices—smoking, overeating and skipping exercise—can all dramatically shorten a person’s health span and lifespan,” Dr. Anthony says. “But other bigger, less obvious population-level issues such as low socioeconomic status, which often disproportionately impacts minorities, also influence biological age. For example, a lower-income person may lack access to or cannot afford healthy food choices leading to food or nutritional insecurity. And if that same person has less access to safe green spaces, they may struggle to get adequate physical activity.”

People trying to live a healthy lifestyle might find their biological age diverging from their chronological one by only a year or two. If they are disciplined with their diet and exercise and don’t have any significant health or genetic issues, they might even be biologically younger than their chronological age.

But in the U.S., where 74% of the population is overweight or obese, many people would be shocked to learn their biological age. Dr. Anthony has been with clients when they realize they are 10 or 15 years older biologically than their chronological age. He tells those people not to feel overwhelmed because improvement comes quickly for those who put the work in.

“Within 90 days, you can see meaningful change,” he says. “And people that keep working for three to six months can lower their biological age by up to two years.”

So the first step to living healthier longer is for a person to understand a better indicator of health like biological age.

But learning this important measure has been easier said than done. It can require having health, genetic and lifestyle data about a person on hand. Then that information gets processed through complicated formulas to synthesize it into a single number.

That’s why, until recently, biological age was a critical bit of knowledge that was out of reach for the average person.

Biological age enters the digital age

Enter the age of apps, where the process that once took saliva and blood samples and involved lengthy testing has gone high-tech. Researchers have shrunk the barriers to entry into algorithms anyone with a smartphone can access. The result is JuvYou, an app that uncovers a user’s biological age and gives personalized recommendations on how to improve it.

Even before entering a bunch of personal information, the app starts estimating a person’s biological age. And after a user begins answering questions related to demographics, body type, health status, and lifestyle, JuvYou’s artificial intelligence goes to work crunching numbers and leveraging Big Data insights to arrive at an even more accurate biological age.

But that’s only the beginning of the information journey. By connecting to the rest of a person’s smart health ecosystem—think real-time updates via Apple Health or Keto-Mojo—JuvYou tailors its approach to the user’s diet, exercise, lifestyle preferences, and needs. Users get custom plans and suggested daily actions that help them achieve their goals. The app then monitors a person’s progress and generates simulations that show what today’s lifestyle choices mean for tomorrow’s health.

“JuvYou is an app meant to be an affordable, accessible and meaningful way for people to learn their biological age and what they can do to improve it,” Dr. Anthony says. “We know we can help people decrease that number in significant ways within a few months through the app. That’s excellent news. In my mind, that’s a great ROI—a return on their health investment.”


We’re using the wrong number when someone asks, “How old are you?” Biological age is a better way for people to understand their health than chronological age. But learning that number has been out of reach for most because of the data and analysis that goes into it. Researchers have now developed powerful, app-based algorithms that make biological age available to anyone.