Have you ever wondered how your body is aging, or why some people seem not less, but more vibrant the older they get?

Those are just some of the questions a doctor at Northwestern Medicine is trying to answer. In short, Dr. Douglas Vaughan wants to know why some people are better at getting old.

"If we can slow down aging, just a little bit, we can push back the onset of disease and we can give people a longer health span," said Vaughan, director of the Potocsnak Longevity Institute at Northwestern Medicine.

The cardiologist is leading research into the difference between a person's chronological age — how many years they have lived, and their biological age — how old their body actually is.

"We are in a place where the biology of aging has been demystified," Vaughan said. "The ability to measure biological age in a way that never existed before."

The foundation of his research came from a small Amish community in Indiana, where Vaughan found that a genetic variation in about 10% of the population has them living a decade longer on average.

"They can teach us a lot about what healthy aging, what's required for healthy aging to take place," said Vaughan.

That work has evolved into an international examination of aging that Vaughan leads at the Potocsnak Longevity Institute.

 "As you get older, you want to know, like, am I going stay sharp?" said Kalinda Marshall, a study participant.

The researchers use a series of tests to calculate biological age, including a scan of patients' retinas, an analysis of their movements, a measurement of their body mass in a machine called a Bod Pod, and an electrocardiogram for heart function.

AI then scours a mountain of data to come up with a number. CBS News Chicago's Charlie De Mar went through the tests, and found that his biological age was four years younger than his chronological age.

"Artificial intelligence gives us the opportunity to find patterns and the data that we can't find with our eyes, that we can't detect with a human brain," said Dr. Josh Cheema, a cardiologist on the project.

The work at the longevity institute has a special focus on people in marginalized communities, and those living with long-term medical problems.

"We are really interested in finding out ways to slow down aging in people that are  disadvantaged," said Vaughan. "Finding interventions that can help people live healthier lives and have a longer health span is extremely exciting to me."

Marshall, who is Black, emphasized how representation is also important in the study, and why she is pleased to participate for that reason.

"Being able to be a representative from a minority community is really important, because I want to know, how does this information measure up to people like me?" she said. "You know, like my information's going to be different than you as a white male."

A network of similar labs on three continents is in the works, and there are already signs of progress. Pills that mimic the genetic variation that helps people in the Amish community researchers studied live longer has done the same thing for mice in trials.

"So theoretically, we could bring this advantage to everybody, to the masses," said Vaughan.