Nir Barzilai was 13 when he walked beside his 67-year-old grandfather and saw, for the first time, what getting old looked like: a balding man moving slowly, telling stories about everything he used to do. “It just sunk in that, oh, one day I’m going to age too,” Barzilai told TIME. He wanted to still be able to do things when that day came.
Decades later he is one of the best-known voices in longevity science. He is a professor of medicine and genetics at the Albert Einstein College of Medicine and directs the Institute for Aging Research there, as well as BIO VITAL, a center for validating interventions that target aging. His argument is simple. Aging drives heart disease, cancer and Alzheimer’s, so go after aging and you go after all three.
What the centenarians show
The evidence he leans on comes from people who reach 100. Barzilai told TIME he has collected data from about 850 centenarians and their families. They developed diseases 30 years later than most people do, and they were sick for only a short stretch at the end of life. He calls this a “contraction of morbidity.” In his phrasing, they are sick for weeks at the end rather than years.
Much of that advantage, he said, is genetic. About 60% of his centenarians carry something in their genome that interferes with the action of growth hormone. His theory is that growth hormone helps when you are young, but later in life the body is better off spending its energy on repair. Small dogs outlive large ones and ponies outlive horses, he noted, and in the lab animals live much longer when growth hormone is knocked out.
The genes are not a verdict, in his view. Once researchers identify one, they can often design a drug that does the same job. His group has given an antibody against growth hormone to animals, and the animals lived longer. Whether that carries over to people is untested. The American Federation for Aging Research is now recruiting 10,000 centenarians for a “super-ager” study meant to confirm the findings and turn up more longevity genes.
Drugs already on the shelf
Barzilai points to medicines that are already approved by the U.S. Food and Drug Administration and seem to touch the biology of aging: the diabetes drug metformin, GLP-1 drugs and bisphosphonates, which are used for osteoporosis. A 2024 paper he co-authored with the European Society of Medicine named several approved drugs as candidates for long-term trials, including semaglutides and metformin. He and his co-authors wrote in a 2016 essay in Cell Metabolism that metformin has “demonstrated protective effects against several age-related diseases in humans.”
He is blunt about what he does not trust. Supplements are “a huge, huge problem,” he said, because a bottle may not contain what the label claims and the interactions are poorly understood. He also cited a recent paper finding that people who took multivitamins did not have a lower risk of dying. Sleep, exercise, diet and social connection, in his telling, have real biological backing at any age.
His own routine is plain. He fasts about 16 hours a day, counting from the end of dinner. He says he lost some weight, gained muscle and lost the midday fogginess he used to have. He adds that it is not for everyone.
The wider role
Barzilai has published more than 360 papers and wrote the 2020 book “Age Later.” He co-founded and presides over the Academy for Health & Lifespan Research, where he helps lead the Super Agers Initiative. He sits on the board of the American Federation for Aging Research and has won the IPSEN Longevity Award and the Irving S. Wright Award. The DOC conference announced in February 2026 that he would join its 2026 faculty.
He does not claim to be chasing immortality. “I want us to be healthy and then die one day,” he told TIME. The research is still a work in progress, and none of it is a substitute for medical advice. Anyone thinking about taking a drug or changing a routine for aging reasons should talk to their doctor first.
Sources
- Longevity Science | Nir Barzilai, M.D. Joins DOC 2026 Faculty – DOC
- How to Die Young at a Very Old Age
