Radically extending human life

$1 million prize dedicated to “ending aging”

“I feel like it’s inevitable that we’re going to solve aging,” says Joon Yun, the benefactor behind a new $1 million prize of which goal is to extend the healthy human lifespan beyond its current limits. Yun, a doctor and healthcare analyst, launched the Palo Alto Longevity Prize on September 9. 11 teams of scientists will compete to achieve milestones toward the ultimate goal of “ending aging” in humans.

The prize is split into two parts. $500,000 will be awarded to the first team who can successfully turn back the biological clock in the heart of an older mammal, such as a mouse. The teams will compete to restore the older mammal’s heart rate variability — how the duration of the pauses between heartbeats varies over time — to that of a young adult. The hope is that eventually the same procedure could be applied to humans, setting the heart of a senior citizen ticking like that of a sprightly twentysomething.

Another $500,000 will be awarded to the first team who can extend a mammal’s lifespan by 50 per cent through the same or similar methods. Since the average life expectancy in Canada is 81, a similar effect in humans would translate to the average Canadian living to be over 120 years old.

The search for a cure

The Palo Alto Longevity Prize reflects a turning tide in the way that doctors and scientists look at aging. For the most part, aging is perceived as a normal and natural part of life. However, a growing number of researchers are beginning to see aging as a disease, like cancer or Parkinson’s, and are searching for a cure. Most of us have lost someone we love to due to aging-related causes of death such as heart disease, and we are bound to lose more loved ones as time goes on. Aging touches everyone. This makes the search for a cure deeply personal.

Doris Taylor, the Director of Regenerative Medicine Research at the Texas Heart Institute, is leading one of the 11 teams competing for the prize. Her team plans to treat aging by replenishing the body’s supply of stem cells, the generic cells from which all the body’s specialized cells are formed. Taylor describes her mother’s passing as the moment she realized that scientists need to better understand the aging process. “When my mom passed away, she was healthy most of her life, until the last week or so of her life,” she recounts. “As I saw her deteriorate very rapidly in just a week, it became very obvious to me we have no idea what aging really does, or is, or how it happens.” Taylor is optimistic about the future of life extension research. In her team’s promotional video, she claims that “aging is both a failure of stem cell number and stem cell function.” The solution, then, is clear to her: “It’s really not that complicated. Replace stem cell number. Replace stem cell function. Prolong life.”

Living long enough to live indefinitely

Making 120 years old the new 80 years old is impressive, but it’s not “ending aging.” So how can Yun set such a lofty goal for Taylor and other competitors? The key is the potential runaway effect of life extension research. If those of us who are alive today live long enough to benefit from the sort of medical treatment that would extend life by forty years, we may end up living for hundreds or thousands of years. The idea is that during the extra decades of life that an initial treatment would give us, science and biotechnology would continue to progress and develop new treatments that would extend our lives even further.

Aubrey de Grey is a biologist and life extension advocate who sits on the advisory board of the Palo Alto Longevity Prize. He calls this runaway effect “longevity escape velocity,” an analogy to the speed a rocket needs to reach before it can break free from earth’s gravitational pull and sail through space indefinitely. Just like a rocket escaping the earth’s gravity, de Grey claims that we will escape death by aging when we pass a tipping point where every decade, new life extension research will be adding over a decade to our lives. Once we reach that point, the sky’s the limit.

If those of us who are alive today live long enough to benefit from the sort of medical treatment that would extend life by forty years, we may end up living for hundreds or thousands of years.

De Grey argues that aging is the accumulation of damage to our bodies, an inevitable byproduct of our bodies’ normal functioning. To reverse aging, de Grey claims, all we need to do identify and repair the different kinds of damage that occur. “Longevity escape velocity,” then, is the point at which damage can be undone faster than it accumulates. “Once we are really, truly repairing things as fast as they go wrong, game over,” de Grey says in the documentary The Immortalists. “We will have the ability to live indefinitely.”

De Grey believes that aging related deaths are “humanity’s worst problem” since it is responsible for two-thirds of deaths worldwide — 100,000 of the 150,000 people who die every day die of aging-related causes. He sees himself as on a mission to save lives. “Even if I bring forward the defeat of aging by just one day,” de Grey says, “that’s 100,000 lives that I’ve saved.”

Do we want to extend life?

Some people are alarmed about the social ramifications of life extension research. The two main concerns are overpopulation and unequal access to life extension medicine.

Perhaps counterintuitively, population has a lot more to do with the birth rate than with the death rate. Even if nobody ever dies, population growth will run into diminishing returns as long as couples have less than two children on average. A demographic study by Leonid Gavrilov and Natalia Gavrilova looked at what would happen to the population of Sweden if aging were stopped completely. They projected that the country’s population would only grow by 22 per cent, from 9.1 million to 11 million, over the next 100 years. As long as a majority of people are content with having no more than two children, population growth will decline over time.

What about unequal access? Although people commonly assume that medical treatments to extend life would only be available to the rich, they don’t explain why such treatments would be different from any other kind of medicine. Access to medical treatment is distributed more equally in some countries, less equally in others, and very unequally on a global scale, but the advancement of medicine has nothing to do with that. Nobody says we should be concerned about curing cancer because only the rich will be able to afford the cure. Whether or not treatments to reverse aging are equally available to everyone is independent of whether those treatments get developed in the first place.

Yun, in an interview on Bloomberg TV, explains why medicine that keeps the body in a youthful state will ultimately reduce the costs of healthcare, giving all healthcare systems an economic incentive to offer that medicine to their patients. “Think about your body as having a homeostasis system,” Yun explains. “When we’re young, it helps our body self-tune, and as we get older, especially beyond the age of forty, the system starts breaking down.” Once the body loses the ability to self-tune properly, “we create this thing called a healthcare system to try to make up for the lack of homeostasis. But imagine if we could put the healthcare system back in the body, allow the body to self-tune. Then we can spend those $2 trillion [Americans] spend right now on healthcare on something else, such as education.” Since age-related chronic diseases take up most of the overall cost of healthcare, treatments that reverse aging would make healthcare less expensive. Rather than being exclusively for the rich, those treatments would end up being more affordable than the medical care that exists today.

A less serious, but perhaps sadder objection to life extension is that we’d all get bored living so long. But should weariness with life be treated any differently in a 200-year-old than in a 20-year-old? Is a desire for an end to life in a 200-year-old “normal” or is it a sign of depression? The thought behind this objection seems to be that the joy of living is a limited resource that can be used up over time. To life extension advocates, however, the joy of life seems unlimited. De Grey says he “can’t imagine ever running out of new things” he would “like to do”.

De Grey re-frames the issue of life extension by asking, “Why do you want to die?” The overarching argument of life extension advocates is that death caused by aging or ‘natural causes’ is no different from death caused by anything else. For them, the question ‘Do you want to live longer?’ is ultimately the same as the question ‘Do you want to live?’ The passion driving advocates like de Grey comes from the belief that passivity about life extension is passivity about life itself.

Is life extension a pipe-dream?

Since 2009, de Grey has been working toward that goal at the SENS Research Foundation, a non-profit organization in Mountain View, California that he co-founded to pursue his plan to repair all the different kinds of damage that are believed to constitute aging. He calls that plan SENS, or Strategies for Engineered for Negligible Senescence. The SENS Research Foundation now houses seven scientists working on research related to the SENS plan, and has funded or is currently funding studies at over a dozen universities and outside research institutions.

Since it began receiving public attention, the SENS plan has struggled to attain mainstream credibility. In 2005, the MIT Technology Review issued a challenge to biologists, offering a $20,000 reward to anyone who could demonstrate that the SENS plan is not “worthy of serious consideration.” Three written submissions were published and a panel of judges was convened by the Review. The judges concluded that none of the submissions successfully debunked the SENS plan. However, they awarded half of the prize money to biologist Preston Estep and his colleagues for its eloquence. Estep and his colleagues condemned the SENS plan as “pseudoscience” and a “pipe-dream.” The judges concluded that although the submission presented “many reasons to doubt SENS,” Estep and his colleagues were “too quick to engage in name-calling, labeling ideas as ‘pseudo-scientific’ or ‘unscientific’ that they cannot really demonstrate are so.” One of the judges was biologist Craig Venter, known for his key role in the Human Genome Project and his breakthroughs in synthetic biology. Venter summed up the judges’ opinion by writing, “Estep et al. in my view have not demonstrated that SENS is unworthy of discussion, but the proponents of SENS have not made a compelling case for it.”
The credibility of the SENS Research Foundation has since been boosted by the fact that it has attracted some prominent scientists to its research advisory board.

One such scientist is Anthony Atala, the Director of the Wake Forest Institute for Regenerative Medicine. Atala made headlines in 2006 when he led the first-ever implantation of an artificially grown organ, a bladder, into a patient. Since then, under Atala’s leadership, the Wake Forest Institute has implanted lab-grown urethras and vaginas into patients and is experimenting with artificial kidneys, livers, and skin. In the future, techniques such as these could be used to replace body parts that have deteriorated from old age with new, healthy parts grown in the lab. Another prominent scientist who has joined the SENS Research Foundation’s advisory board is Harvard geneticist George Church, best known for his work in human genome sequencing, the process by which the complete DNA of a person can be examined.

The SENS Research Foundation remains relatively small and poorly funded. In 2012, its budget was under $3 million. Even so, the Foundation has managed to make progress. One of its greatest successes to date involves 7-ketocholesterol, a type of cholesterol waste product of the body’s normal processes. As it accumulates in the body over a lifetime, it reaches toxic quantities. 7-ketocholesterol is associated with atherosclerosis, an age-related disease where the walls of the body’s arteries thicken and harden. The Foundation’s researchers discovered a species of bacteria that consumes 7-ketocholesterol and isolated the enzyme those bacteria use to digest it. That enzyme could, one day, be used in a drug that would break down 7-ketocholesterol in the body. The build-up of 7-ketocholesterol is one tiny example of the naturally occurring damage to the body that de Grey claims is responsible for human aging. As studies like these add up, finding more solutions to more examples of damage, de Grey believes we will eventually have the solution to aging as a whole.

The dying of the light

Despite lambasts by critics, life extension advocates burst with optimism. Yun and de Grey believe it’s only a matter of time until aging is solved. Likewise, biologist Bill Andrews confidently predicts, “Hundreds of years from now, we’re going to look back and be shocked by this horrible world that we all used to live in where people used to get old and die.” The motto of Andrews’ company, Sierra Sciences, succinctly captures the spirit of life extension research: “Cure aging or die trying.” If this optimism proves to be justified, for the first time ever, people will be faced with a genuine choice of whether to go gently into old age or to rage against it.