Not so long ago, researchers thought we aged the same way our cars do—after years of wear and tear, the engine is bound to break down. But today scientists think the process may not be inevitable. Over the last 20 years, they have found a handful of genes that control the way we age—and they hope to manipulate them to slow the process down.
On Wednesday, some of the leading researchers in the field met at Harvard University to discuss the state of anti-aging science at the Aging & Healthy Lifespan conference.
“There’s still a public perception that aging is natural and that it’s acceptable,” said David Sinclair, a researcher at Harvard Medical School and founder of a drug company working on the issue. “I think of aging as a disease because it makes you want to treat it.”
Unlike our cars, even when we’re still shiny and new, our bodies are always breaking down. But when we’re young, our cells have a team of tiny mechanics that constantly replace and repair the broken parts of our DNA to keep us running smoothly. As we age, the repair team slacks off and our health deteriorates.
Those repair processes are complicated and involve many chemical pathways inside our cells. But they are controlled by just a handful of genes. So some scientists think a drug that targets one of those genes might amp up the repair work and thus help prevent or treat a host of age-related diseases like diabetes or heart disease.
It’s done wonders for a microscopic roundworm called C. elegans that scientists use as a model to study larger organisms. Researchers have found that by changing just one of the genes that affects aging, they were able to double the worm’s lifespan. When they targeted multiple genes, the worms lived six times as long as normal, and remained healthy. At the conference, Cynthia Kenyon, a scientist at the University of California, San Francisco, showed movies of a normal worm at the end of its typical two-week lifespan. The worm was listless and still, barely nodding its head. But one of her long-lived worms was still wriggling away energetically, just like a young worm.
“This worm should have been dead a long time ago and there it is moving around,” said Kenyon. Studies in mice have shown the same effect, she said. Targeting the genes that control aging not only increases lifespan but seems to improve overall health—so that the animals remain vital as they live longer.
“The model organisms give us at least the idea of having a long healthy lifespan and dying quickly and painlessly,” Kenyon said. “Sounds pretty attractive.”
Of course, it’s a long way from a worm to a human being. But scientists have found a number of genes and processes that seem to work the same way in humans. The most well known are called sirtuins, a class of proteins that repairs broken DNA in our cells.