It's not age that kills you, it's disease. Imagine if we could stop the disease?

Scientists in California have successfully reversed the signs of aging in mice, making living longer a tangible possibility for humans.

Maija Kappler 5 minute read March 24, 2022
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How could advancing technology extend human life? GETTY

Babies born 50 years from now could live up to age 150 with the help of anti-aging technology, some leading futurists say.

It’s a bold claim, and one that clearly needs a lot more study before it can be taken as a serious prediction. But early studies on mice shows promise. Earlier this month, researchers at the Salk Institute for Biological Studies in La Jolla, California successfully reversed signs of aging in mice using cellular rejuvenation therapy.

“We are elated that we can use this approach across the life span to slow down aging in normal animals,” the study’s co-author Juan Carlos Izpisua Belmonte said. “In addition to tackling age-related diseases, this approach may provide the biomedical community with a new tool to restore tissue and organismal health by improving cell function and resilience in different disease situations, such as neurodegenerative diseases.”

Just like with humans, every cell in a mouse’s body changes as they age. Scientists added a combination of four reprogramming molecules referred to as Yamanaka factors (to be precise, the molecules are Oct4, Sox2, Klf4 and cMyc) to the mice’s cells, which effectively “dialed them back” into stem cells.

The researchers tested one group of mice by giving them regular doses of the Yamanaka factors from the ages of 12 months to 22 months, which they estimated to be the equivalent of ages 35 to 70 in humans. One group got the treatments from ages 15 months to 22 months (50 to 70 in humans), and another got the treatments for just one month when they were 25 months old (about 80 in human years).

The addition of the Yamanaka factors was successful at both accelerating muscle regeneration and countering the signs of aging, which in turn increased the mice’s lifespan. The mice who got longer treatments had significant benefits: when those mice were injured, they healed quickly and were unlikely to have permanent scars — which is common in younger mice, but rare in mice of their age.

And significantly, there were no negative impacts on the health or behaviour of the mice — no blood cell changes, no neurological changes, no cancers.

“This suggests that the treatment is not simply pausing aging, but actively turning it backwards,” the study notes, although it adds that “more research is needed to differentiate between the two.”

Some predict it will happen in humans

Computational biologist Dr. Andrew Steele believes that this kind of technology will soon be used on humans.

“We’ve got the platform working in humans, and the concept working in mice,” he told the UK’s iNews. “I don’t think it’d be totally mad to see some reprogramming by rejuvenation in the next 10, 15, 20 years… You’d be a fool to bet against it working in the next 50 years.”

He suggests that it could happen by introducing new genes into existing human cells.

“We’re already using gene therapy in humans,” he told the outlet. “It’s in its infancy, but it’s existing technology. It feels like decades, rather than centuries, before we’re really good at it.”

Jürg Bähler, a geneticist at University College London, agrees. “There’s been a huge increase in lifespan in the last 200 years, from 30 or 40 years to something like 80 now,” he said.

But he doesn’t think it makes sense for people to age beyond 150. “Some people, including myself, would say there’s a natural ceiling for human life, about 150, and you can’t go beyond that,” he said.

Steele has long believed that aging is the world’s most significant source of suffering — and that it’s preventable.

“Ageing is this inevitable, creeping thing that happens. We’re all quite blind to its magnitude,” he told The Guardian in 2021. “But what do people die of? Cancer. Heart disease. Stroke. These things all [primarily] occur in old people, and they primarily occur because of the aging process.”

Illnesses don’t occur because of aging itself, he adds, but because of the negative effects of aging.

Steele believes that living to an older age, but with better heath, is a possibility.

“The dream of anti-aging medicine,” Steele said, “is treatments that would identify the root causes of dysfunction as we get older, then slow their progression or reverse them entirely.” The idea is that scientists will be able to “come up with treatments that slow down the whole aging process, deferring diseases into the future.”

Ageing is a complex process, of course, and these concepts are all speculative at this point. The Salk scientists say the next step in their research will be analyzing the way specific genes and molecules are changed when they’re treated with the Yamanaka factors, and finding new ways those factors can be delivered.

Maija Kappler is a reporter and editor at Healthing. You can reach her at
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