Who wants to live forever?
Steven Austad predicts the first 150-year-old will be alive by 2150 and he has $500 million riding on it
Steven Austad may have never got around to researching longevity were it not for a bad experience with a lion, a duck, and a wig. Fresh out of college after completing his degree in English literature and trying “to pen the great American novel,” Austad agreed to help a lion tamer friend, who rented out animals to movie studios. In Hollywood, Austad got a job offer to appear on the 1970s TV series The Bionic Woman, dressed as a female heroine being attacked by one of the friend’s African lions. Excited by Austad’s wig and dress, the African lion jumped up and tried to mate with him.
With somewhat dented pride, Austad persevered with the job. But a duck waddling out in front of another lion proved his undoing. Austad was walking the lion on a chain at the time. When the lion jumped on the duck, Austad promptly whacked the lion over the head with the chain, and the aggrieved lion switched his attention to chewing Austad’s leg instead. Some 15 minutes later, another trainer managed to pull the lion off him.
The incident resulted in a six-day hospital stay for Austad and a rethink of his career. So far, among other things Austad had already driven a taxicab in New York and worked as a newspaper reporter. But there’s nothing like being in the jaws of death to awaken a sudden interest in a long life: Austad decided to give up the movie business and study animal behaviour and longevity instead.
“Getting mauled gave me time to stop and think about my future. I found that the whole movie business wasn’t very intellectually stimulating and I wanted to learn more about animals. My own longevity, having a longer life was also a factor,” admits the specialist in comparative gerontology, or the study of aging across species.
[Tweet "It is not going to be common to be 150 but I think that person is out there already, likely a woman"]So Austad returned to academia, earning a PhD in biology from Purdue University before working as assistant professor in the Department of Organismic and Evolution Biology at Harvard University in 1986 and then moving on to the University of Idaho as a full professor. He worked from 2004 to 2013 as a professor at the University of Texas Health Science Center at San Antonio and as interim director of the Barshop Institute before moving to his current role in 2014 as professor and department chair in the department of biology at the University of Alabama, Birmingham.
It was back when he was a budding zoologist, however, that Austad (pictured below) first turned his attention to opossums.
Unlike African lions, it’s hard to get excited about your average opossum: roughly the size of a house cat, they are scraggy, with a rat-like tail and white and grey fur. Even the name normally gets shortened to possum, as if they’re not worth the extra vowel. But this diminutive marsupial may have given Austad a rare glimpse of evolution.
While he was investigating their reproductive behaviour, Austad was surprised by how rapidly opossums aged: the animals suffered from parasites, cataracts and arthritis before dying at the age of two, rather than living the 10-15 years you would expect from a creature its size.
Not so their long-lived cousins on Sapelo Island, five miles off the coast of Georgia: these opossums, which had been living in isolation from predators for thousands of years, lived 25-50% longer, Austad discovered.
TALKING ABOUT EVOLUTION
As predators kill about 80% of opossums on the mainland, living on the island obviously meant opossums stood a greater chance of survival. But Austad’s research showed exactly how much being protected from predators boosted the opossums’ evolutionary odds.
“If animals are being killed for millions of years at such a high rate by predators, it makes little sense for evolution to provide them with the means for long life, such as a good immune system and maintenance of sight, hearing and muscle. But if on this island they have had reduced predator pressure for thousands of years, there may have been an advantage for evolution to provide them with the means for a long life.”
Austad investigated further. Unlike their counterparts on the mainland, who rarely lasted a second reproductive cycle and when they did produce ailing offspring, the island opossums continued to engender healthy young. What’s more, tissue samples taken from tendons (tendons’ molecules can accurately predict age as their molecules age at exactly the same rate as you do, explains Austad) proved that the animals on the island were aging more slowly than those on the mainland.
Most interestingly, the island had been isolated from the mainland for only 5,000 years, suggesting that there are relatively simple ways to alter the rate of aging, which may not require changes in thousands of genes. “It showed that aging is not something that’s a fixed trait of the species like having two arms and two legs but is something that can respond to environmental conditions and can be altered over a reasonable number of generations,” explains Austad.
OF MICE AND MEN
Take diet, for instance: researchers have found you can change the rate of aging in laboratory animals by changing what they eat and how much: mice that eat considerably less live 30-40% longer, although it remains unclear why, adds Austad. Or you can alter aging by inactivating a gene. Or by giving laboratory animals a drug.
“These are simple mechanisms for altering the aging rate, which is fairly heartening news for humans if we’d like to extend their healthy lifespan,” he says.
One of the most exciting advances when it comes to anti-aging is a drug called Rapamycin. This is a natural product, isolated from a bacteria found in the soil on Easter Island, or Rapa Nui in the local language, hence the name. Otherwise, the drug is regularly used as a coating on cardiac stents to inhibit scarring and to fight certain cancers.
Researchers stumbled on Rapamycin’s anti-aging properties by accident. They had difficulty administering the drug in random tests so the laboratory mice were already elderly by the time tests started. When they got the results, the scientists were shocked to find that the female mice tested lived 40% longer and males 30% longer.
Since then, the test results have been confirmed independently several times. And in the course of research, Rapamycin has been found to offer several other advantages. For instance, when given to mice that were genetically engineered to develop Alzheimer’s, Rapamycin delayed its onset. The same was true of heart disease. And of various cancers. Even the rate of age-related cognitive decline was slower in the mice tested.
There were some side effects: for example, some mice tended to become pre-diabetic, while others developed cataracts at an earlier age. But the big breakthrough came through when researchers decided to dose elderly mice with influenza and see if Rapamycin had any effect. It did: the elderly mice given Rapamycin were as well protected against the flu as young mice.
And so the testing moved on to humans. The results were just as dramatic: low doses of the drug taken ahead of a flu shot by people aged 65 or above boosted their immune response to the vaccination by an average of 20%. Next, researchers will be investigating the effects of Rapamycin on Alzheimer’s in humans, Austad said.
AND IF THE DRUGS DON’T WORK?
Drugs aside, the secret to a long, healthy life might already lie in your hands, and your genes: about 25% of longevity is genetic, while 75% is environmental, according to Austad. “For most of us, the chance of living until your 80s and staying healthy is largely down to how you live your life, and you have a lot of control over that.”
The big question remains, armed with medical advances and a healthy lifestyle, how long can we realistically live? Leading researchers seem to be at odds about it. Austad and fellow preeminent aging expert, S. Jay Olshansky of the University of Illinois at Chicago School of Public Health, even have a $500 million bet riding on it, payable in 2150.
Austad has bet that someone will live to be 150 years old by 2150. Olshansky, meanwhile, has bet that we can’t stretch our lifespan beyond 130 years (the oldest person on record to date, Jeanne Calment, died when she was 122 years old). The pair have paid $300 into a trust fund that is expected to grow until Jan 1, 2150 and is payable to the heirs of the winner. The condition is that the 150-year-old be mentally intact and not in a vegetative state.
“It is not going to be common to be 150 but I think that person is out there already, likely a woman. If you look at the dietary restriction experiments on animals and calculate how much of a longevity boost this would be in human terms, it would be roughly the increase from a 122-year-old to a 150-year-old,” says Austad.
“We’re not going to double our lifespan, but slowing the rate of aging by 20% is very doable,” he says, explaining his logic. “We’ve already done it to an extent by better medicine and public health but we’re running out of what we can do with these. Now there’s a whole new era of biology out there where we can tinker with the aging process. It could be a combination of lifestyle plus drugs such as Rapamycin and an anti-diabetic drug. Some people will really respond well to that kind of therapy.”
Who amongst us might still be around in 2150 to see if Austad collects his bet?
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