Science could add decades to the average human lifespan

This article was published by The Globe and Mail on August 18th,  2013.  To see this article and other related articles on The Globe and Mail website, please click here

In a New York City laboratory, a handful of mice are poised to outlive their peers by the human equivalent of 20 years.

Not only will they hang around longer, but their extended lives will be fuller. They’ll recall maze patterns faster than other elderly mice. Their muscles and tendons will be stronger. Their bones will be denser, their skin more supple.

These mice aren’t drinking from a fountain of youth. Scientists tinkered with a protein in a tiny part of their brains called the hypothalamus that is thought to control the aging process.

“What it tells us is the hypothalamus has a regulatory function in aging and that it’s possible to slow down the aging process and increase longevity,” said Dongsheng Cai, a physiologist at Albert Einstein College of Medicine and a researcher on the project.

Anti-aging experiments like that at Einstein have scientists talking seriously about the average lifespan rising by decades, possibly to 120 years, and academics pondering the consequences. What would it mean for the solvency of the health-care system or public pensions? Would it change views on marriage (“Happy 98th anniversary, Grandma and Grandpa!”)? And would anyone really want to live so long anyway?

Versions of the latter question were asked in two recent surveys, one of Canadians, the other of Americans. In the Canadian survey, published last year in the Journal of Aging Studies, 59 per cent of respondents said they would welcome living 120 years “if science made it possible to do so in good health.” The Americans were more reluctant. The survey, by Pew Research and published this month, asked whether people would prefer to live 120 years with the help of “medical treatments that slow the aging process.” The majority – 56 per cent – said no.

Indeed, more than two-thirds of Americans gave their “ideal lifespan” as between 79 and 100 years old, with just 8 per cent wanting to hit the century mark. The answers were nearly uniform across the board, with 18- to 29-year-olds being the least likely to idealize living to 100.

Dr. Gloria Gutman, who founded the Gerontology Research Centre at Simon Fraser University, suspects the tepid American response to long life was influenced by the question’s lack of clarity on staying healthy.

“The average person thinks in the stereotypical point of view that old means decrepit,” Gutman said. “But if you’re looking at it as extending the vitality of living, then why not?

“If I have my mental and physical capacity, then why wouldn’t I want to live to see how my kids are going to spend my money and how my grandchildren are going to turn out? … None of us wants to be drooling in a nursing home.”

In recent years, scientists have prolonged the lifespans of yeast and fruit flies and roundworms. The results of those experiments are not yet a reality for people, and may never be because of the complexities of human physiology.

For instance, experiments with semi-starvation diets have been shown to lengthen the average lifespans of rats, hamsters and even dogs. But when scientists tried “caloric restriction” experiments on rhesus monkeys, a close biological relative of humans, they concluded it made no difference. While the semi-starved monkeys showed a lower incidence of cancer than normally fed monkeys, they all died just the same.

At the Strategies for Engineered Negligible Senescence (SENS) Research Foundation in Mountain View, Calif., the thinking is that aging is a disease that can be controlled and “cured” through a variety of “rejuvenation biotechnologies,” like a mechanic would keep a vintage car running indefinitely.

The foundation spends millions of dollars a year on research to find ways to repair age-related damage to the body. An ongoing project seeks to extract “extracellular junk,” malformed proteins that are no longer useful, from the brains of patients with Alzheimer’s disease.

“Most people have this idea that aging is natural and sometimes desirable, and the idea that we would come along and defeat aging just doesn’t compute,” said the foundation’s chief scientist, Dr. Aubrey de Grey, who believes aging and death are neither synonymous nor inevitable.

Is he really saying immortality is possible? “Of course not, there are always trucks on the road,” de Grey said to accentuate his belief that while there are many causes of death, aging does not have to be one of them.

“That kind of attitude is just the epitome of human hubris,” said Brendan Leier, a clinical ethicist at the University of Alberta’s John Dossetor Health Ethics Centre. “It’s not the duration of life that’s the problem for us, but the quality of life. Quality is what makes it meaningful.”

Albert Einstein underwent surgery to stem the rupture of an abdominal aortic aneurysm. Six years later, as he lay dying of the condition, he refused another operation, saying, “It is tasteless to prolong life artificially. I have done my share, it is time to go. I will do it elegantly.”

He died the next day.


If a 120-year lifespan sounds like science fiction, consider that advances in medicine – from antibiotics to heart bypass surgery and pacemakers – and improvements in hygiene, nutrition and public health have boosted Canada’s life expectancy to north of 81 years from about 50 since 1900.

So what’s 120 years when test mice at Albert Einstein College of Medicine in New York City suggest that reducing a single protein in an almond-sized pocket of the human brain could produce a centenarian?

Or in an age when researchers in a North Carolina lab are reproducing viable human bladders from stem cells?

More and more people are living to the century mark. Between 2001 and 2011, the number of centenarians in Canada jumped 53 per cent to 5,825. Statistics Canada predicts the number will climb exponentially to 49,300 by 2051.

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