Can aging be reversed? Harvard professor says it's possible

The search for the fountain of youth is underway at a medical school lab at Harvard. It's being steered in part by respected biologist David Sinclair, an advocate for understanding and possibly lengthening the human lifespan.

Sinclair's new book 'Lifespan' chronicles the aging process and explores how people age on a molecular level. In a recent interview with Good Morning America, the Professor in the Department of Genetics at Harvard Medical School dove into the secrets of aging.

"If I took your blood right now, I could tell you how old you are biologically," Sinclair said. "Now that's a very accurate clock. Scary, right? Now that we have this clock of age, we can ask what accelerates it and what slows it down and what reverses it - literally turn that clock backwards, by a lot."

Decades of research shows putting the body under stress with measures like high-intensity interval training, cold exposure and calorie-reduction diets like intermittent fasting can help fight the process.

Sinclair says the next breakthrough in anti-aging may include boosting the body on a cellular level. Medicines and supplements will theoretically treat aging as a disease. He says the idea is showing promise in labs.

"There's 20, 30 years of world-class science that shows that you can quite dramatically slow down aging, and even more recently, we found that you can reverse the clock, not just in mice, but possibly in people," Sinclair said.