Health & Fitness

Two preeminent aging experts are on opposing sides of a bet that someone living today will be alive in 2150.

At stake is not only a wager but also the answer to fundamental questions about the biology of aging and the ability we have to stretch our life span.

If he hadn’t been savaged by a lion, Steven Austad might never have discovered the elasticity of aging. Just out of college, he became friends with a  lion trainer who rented animals to movie studios. Soon he was in Hollywood, working with exotic felines. One morning, he was walking Orville, a 300-pound lion, when a duck darted out from some reeds. The 2-year-old lion pounced, and Austad disciplined the big cat with a slap on the head. Orville released the duck, but then pounced on Austad. He knocked Austad down and sunk his teeth into Austad’s knee. Austad didn’t struggle because he knew lions are possessive of their food and Orville might lunge for his neck next. So he waited…for 15 minutes…with the lion gnawing on his leg. Finally, another trainer spotted him and sprayed Orville with a fire extinguisher. Austad spent six days in the hospital and realized that he needed to find a safer, more rewarding way to work with animals. He became a biologist and traveled the world, ending up on the remote savannas of Venezuela, studying a less frisky animal, the opossum.

While trapping female opossums, attaching radio collars, and catching them again every month to count the babies in their pouches, Austad noticed something bizarre. “They were falling apart at an incredible rate,” he says. “I’d catch one that would look great, and then I’d catch her a couple of months later and she’d have cataracts and arthritis.” Why, he wondered, did they age on such a fast schedule? Why did they get old at all? As animals age, their cells show increasing signs of damage. But animals also have the ability to repair their cells. So why weren’t the opossums keeping their bodies in good working order until they were killed by a predator or a parasite? “That question doesn’t strike enough people as a mystery on its own,” he says. “Just about everything we are familiar with ages, so people just accept it as a given. But I don’t.”

Austad scoured the scientific literature for ideas about why we age, and he found a hypothesis that explained it: Aging is an inescapable by-product of evolution. Repairing damaged cells may let an animal live longer, but it also requires a lot of energy that could be used for other things—like maturing faster and having bigger litters. In Venezuela, Austad proposed, living fast and dying young was the best way for the opossums to pass on their genes. Stalked by jaguars, they were likely to be killed anyway, so staying youthful was a waste of effort. If Austad was right, opossums that enjoyed a safer life might also enjoy a slower, longer one.

On Sapelo Island, off the coast of Georgia, Austad found a population of predator-free opossums. They had it so easy that he often found them sunbathing in the road. He tagged and tracked them for the next few years. The chilled-out island opossums, he discovered, lived 25 percent longer than their cousins on the mainland. They also enjoyed better health for a longer time. It was as if Austad discovered an isolated Pacific island on which people regularly lived to 100.

Austad started to formulate an idea that would inform his research for the next 20 years: Aging isn’t set in stone. It’s more like Silly Putty, stretched and squashed as animals adapt to their changing world. In fact, Austad and other researchers found they could make animals live longer, either by changing their diets or tinkering with their genes. These experiments led Austad to a startling conclusion: It might be possible for man to take over where evolution left off and slow the rate at which we age, stretching our life span.

It wasn’t an idea he embraced lightly. As one of the nation’s preeminent experts on aging, Austad, a professor of cellular and structural biology at the Sam and Ann Barshop Institute for Longevity and Aging Studies, at the University of Texas, spends a lot of time debunking the many bogus claims that float around about how to live forever. Yet he could not ignore the possibility that someone would eventually develop a drug that could slow the aging process, adding healthy years to people’s lives. By February 1999, Austad was ready to go on the record. At a gerontology symposium, a reporter asked him if, and when, someone would live to the age of 150.

“I think that person is alive already,” he replied.