You have two ages, chronological and biological. Here's why it matters

Reminiscent of a scene from "The Social Network," the whiteboard in researcher and professor Morgan Levine's Yale Medical School office is covered in a series of letters and numbers. She clicks the red cap back onto the dry erase marker and steps back to admire her work.

In front of her, the equation stretches across multiple lines, taking up much of the surface. This algorithm represents a new way of thinking about age.

"In my lab, we work on a lot of different types of aging measures," Levine said. "One of the most recent ones is based on blood measures you get at your normal doctor's appointment. We basically take those and combine them using different algorithms to get what we call someone's phenotypic age or biological age."

Essentially, everyone has two ages: a chronological age, how old the calendar says you are, and a phenotypic or biological age, basically the age at which your body functions as it compares to average fitness or health levels.

"People of the same chronological age aren't all at the same risk for developing cardiovascular disease or cancer or even dying," Levine said. "What [the biological age] does is actually give us a better idea of where someone stands for their age."

"Chronological age isn't how old we really are. It's a superficial number," said professor David Sinclair, co-director of the Paul F. Glenn Center for the Biology of Aging at Harvard Medical School. "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. Biological age is number of candles we really should be blowing out. In the future, with advances in our ability to control biological age, we may have even fewer candles on our cake than the previous one."

Levine and her team identified nine biomarkers taken in a simple blood test that seemed to be the most influential on lifespan. The biomarkers include blood sugar, kidney and liver measures, and immune and inflammatory measures.

Levine plugs those numbers into the computer, and the algorithm does the rest.

People with a biological age lower than their chronological age have a lower mortality risk, while those aging older from a biological standpoint have a higher mortality risk and are potentially more prone to developing the diseases associated with the higher age range.

But perhaps what's most important here -- unlike results from genetic testing -- is that these are measures that can be changed. Doctors can take this information and empower patients to make changes to lifestyle, diet, exercise and sleep habits, and hopefully take steps to lower the risk and improve their biological age.

"I think the most exciting thing about this research is that these things aren't set in stone," Levine said.

"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, who has been fascinated with aging ever since she was a young girl, even entered her own numbers into the algorithm. She was surprised by the results.

"I always considered myself a very healthy person," she said. "I'm physically active; I eat what I consider to a fairly healthy diet. I did not find my results to be as good as I had hope they would be."

She now tries to get more sleep and changed her diet and exercise routine. "It was a wake-up call," she said.

Levine is working with a group to provide access to the algorithm online so that anyone can calculate their biological age, identify potential risks and take the steps to help their own health in the long run.

"No one wants to live an extremely long life when they are in very poor health and have a lot of chronic disease," Levine said. By delaying the onset of diseases and cognitive and physical functioning problems, "people can still be engaged in society," she said. "I think that is the ideal we should be striving for."