What would you do with 20 extra years? Scientists extending 'healthy lifespan'

Joanne Laucius, Ottawa Citizen 10 minute read January 30, 2020

Twenty years from now, a 60-year-old might be able to buy a drug that will extend healthy life by a decade or two.

The treatment might be taken over a period of six weeks or so. The end result? A boost to the immune system and protection against a host of age-related diseases, including heart disease, cancer and dementia.

This kind of intervention wouldn’t be the fountain of youth — it won’t turn back the clock and make that 60-year-old a 16-year-old again. It wouldn’t offer eternal life. But it would produce an extended “healthspan” — extra years spent free of chronic age-related disease and disability.

At least, this is one version of the near future. Some, like gerobiologist Matt Kaeberlein, believe that an extended healthspan is a likely near-future scenario — and policy makers, governments and the medical profession should be prepared for it.

It has been done with animals like worms, fruit flies and mice. There have even been some promising early results using a drug called rapamycin in a study involving pet dogs.

Whether or not it will actually happen with people is still debatable. But the idea and repercussions around it are real enough to warrant an entire issue of the journal Public Policy & Aging Report, which asked the question: Is aging a disease?

Chinese 104-year-old twins, Cao Daqiao (senior, R) and Cao Xiaoqiao talk at home in Weifang, east China’s Shandong province on November 29, 2009. According to the Shanghai Guinness World Records, this twin sisters, who were born in 1905, were the oldest living twins in the world as of 2009. STR / AFP VIA GETTY IMAGES

Kaeberlein, a professor at the University of Washington who studies the biological mechanisms of aging, is asking for nothing less than a paradigm shift in the medical approach to the diseases associated with aging. He thinks it’s reasonable to expect there will be products on the market within the next 20 years that could extend healthy life, although it will take a runway of several decades to prove it works.

“This is a much more effective approach toward health than the traditional medical approach of waiting until people are sick and trying to cure their disease.”

As it stands, physicians treat individual diseases. The risks for a number of diseases, including many types of cancer, heart disease, diabetes, Alzheimer’s and neurological disorders like Parkinson’s disease, increase with age. The biggest risk factor in heart disease, for example, isn’t smoking, too many cheeseburgers or some other environmental cause. It’s age.

One estimate suggests that curing cancer or heart disease would increase life expectancy for only three or four years and curing both cancer and heart disease would increase life expectancy by less than 10 years because the risk of other kinds of diseases continue to increase exponentially. If aging could be slowed down, then life expectancy could be increased by two or three decades.

“Modern medicine has gotten pretty good at keeping sick people alive, but we are not very good at curing age-related disease,” said Kaeberlein. “By treating one disease at a time, we haven’t done anything to prevent all of the other age-related functional declines from happening in that person.”

Christian Mortensen, 114-years-old, smokes a cigar at his home in the Aldersly Retirement Community in San Rafael, CA in 1997. Mortensen was the oldest man alive and celebrated his 115th birthday 16 August, 1997. AFP PHOTO/JOHN G. MABANGLO JOHN G. MABANGLO / AFP VIA GETTY IMAGES

By holding back aging, it is possible to hold back not just one disease, but a whole bunch of them. Age-related chronic diseases are taking an increasing toll on the world economy. One 2017 analysis estimated that half of the global health burden among adults can be attributed to age-related diseases.

“I think you can make an argument that the extended period of time many older people live with multiple comorbidities currently is likely a direct result of the traditional medical approach of treating individual diseases, rather than treating biological aging.”

Others are skeptical that an effective intervention to modify aging is just around the corner.

“I know of no current intervention I would be willing to place a bet on,” said Douglas Gray, a senior s

cientist at the Ottawa Hospital Research Institute and professor of biochemistry, microbiology and immunology at the University of Ottawa. “The motivations are genuine and admirable. I just don’t buy it.”

Researcher Jane Rylett, whose lab at Western University investigates the mechanisms regulating chemical communication in the nervous system, doesn’t believe there is a single silver bullet for aging. What might work is a combination of approaches, she said.

“Never say never. But I don’t see anything on the horizon that would signal something imminent that would allow us to prolong life for, say, 20 years,” said Rylett, who is the scientific director for the Institute of Aging at the Canadian Institutes of Health Research.

“Even if there was a drug targeted at aging, it would affect different people in different ways.”

There are few hurdles to be overcome. One is research funding that recognizes biological aging as a risk factor in a disease. While biological aging accounts for more than 90 per cent of the risk of developing Alzheimer’s, for example, only a fraction of one per cent of the Alzheimer’s research dollars spent in the U.S. is allocated to research on the role of aging in developing Alzheimer’s. To turn the tide on the disease, more resources need to be spent on understanding how aging works, Kaeberlein argues.

In this Aug. 14, 2018 file photo, Dr. William Burke goes over a PET brain scan at Banner Alzheimers Institute in Phoenix. MATT YORK / THE ASSOCIATED PRESS

The other major hurdle is regulatory. Drugs approved by the FDA are approved for an “indication” — that is, the drug treats a named disease. Most of the promising work on aging so far has been with animals, and not very complex animals at that. Translating these findings to people means clinical trials. Some contend that aging has to be recognized as a disease so it can be targeted by a drug aimed at treating it. It’s worth noting, however, that some drugs have long been approved to prevent diseases. Vaccines are an example.

Kaeberlein doesn’t think we should be trying to gain acceptance for the idea that aging is a disease. That’s a semantic argument that distracts from the more important conversation, he said.

“What’s more important is to get people to understand that biological aging is a modifiable process.”

For some, the idea that aging is a disease is absurd and potentially dangerous.

“The thing that excludes aging from being a disease is its universality,” said Gray.

Some animals may live extraordinarily long lives. The naked mole rat, a hairless burrowing rodent native to East Africa which can live more than 30 years — at least 10 times the lifespan for a mouse — is of great interest to scientists. The hydra, a tiny freshwater polyp, may live virtually forever.

There is also great scientific interest in the outer limits of longevity for humans. There have been numerous documented cases of people living over the age of 110. But all humans age and eventually die.

In this Oct. 28, 2014 photo, neurosurgeon Dr. John Sampson places a catheter into a glioblastoma patient at Duke in Durham, N.C. The risk of cancer increases with age. SHAWN ROCCO / THE ASSOCIATED PRESS

In 1825, the English actuary Benjamin Gompertz determined that the likelihood of dying doubled every eight years from the age of about 30. Two hundred years later, even though people live longer, his mathematical model, known as the “Gompertz curve,” still holds. It just distributes death over a longer arc, said Gray.

“There is a genuine problem with ageism in our society, and the last thing we need is for older people to be perceived as diseased,” he said. “The very word invokes an entirely inappropriate response — at least that is my perception. Perhaps it is because to many people the word brings to mind the Spanish Flu or the Black Death, not a universal, passive, and gradual loss of function.”

Geriatrician Dr. Peter Boling agrees. If aging is a disease, simply by staying alive, we are all sick, he said.

While we can and should improve aging by tackling the impact of age-related health problems, aging is inevitable and should be considered a fact of life, not a disease. It’s better to work on preventative measures that will result in healthier people, and better care for those who are sick, said Boling, who is also a professor of medicine at Virginia Commonwealth University.

“The presumption is that the quality of life among older individuals is not good,” he said. “It’s an interesting mix of things when we get older. I’m more and more aware of some of the things I can’t do. I have arthritis. I know changes are taking place in my cardiovascular system. But these things are predestined. I want to say I’m glad for the things I have seen and the experiences I have had. Accumulated experience is part of the aging process.”

Advocating for more basic research funding to learn about the biological causes of aging is a legitimate scientific objective. It will help us understand what makes us tick and may then lead to better health. But it will likely not ultimately uncover a fountain of youth, Boling argues.

He is cautious about the idea of taking drugs with possible side effects, or editing genes to change the aging process. You might, for example, be able to boost the immune system and increase resistance to illnesses such as influenza and shingles, he said. But there might be downstream effects. Aging is a complex process and humans are complex organisms.

“When you change things in a large system, you don’t know what else may occur,” Boling warns.

Both life expectancy (the average number of years a person is expected to live) and health-adjusted life expectancy (the number of years spent in good health) increased in Canada over a 20-year period, according to a study released by Statistics Canada in 2018. Life expectancy at birth for Canadian men was 79.8 years in 2015, but health-adjusted life expectancy at birth was 69.0 years, said the study, based on responses to health surveys. For Canadian women, life expectancy at birth was 83.9 years, but health-adjusted life expectancy was 70.5 years.

Increasing healthspans could save governments mountains of money. One 2013 study estimated that extending a healthy life by only 2.2 years would save the U.S. $7.1 trillion in health-care costs and increased productivity, for example.

But a world where 80 is the new 60 also brings up a lot of questions. Would treatments that extend life be available to everyone, or would this open a new rift between haves and have-nots? Would two more decades of life mean postponing retirement and spending two more decades in the workforce?

“Obviously, there are several policy and social implications associated with an increase in healthy lifespan of 20 to 30 years. Retirement age and social security would need to be redefined, for example,” said Kaeberlein.

A woman exercises with wooden dumbbells during an event marking Respect for the Aged Day at a temple in the Sugamo district of Tokyo, Japan, on Monday, Sept. 19, 2016. The proportion of Japan’s aged has been rising steadily for decades, with U.S. Census Bureau data showing that last year more than one in four Japanese were over 65. TOMOHIRO OHSUMI / BLOOMBERG

He is doubtful it would happen all at once, and it will most likely be a gradual application of new discoveries. “There are also questions about access and who will benefit first from such discoveries and how long it will take for them to become widely available — which can’t be answered right now.”

Kaeberlein would like to see Food And Drug Administration approval of an intervention to target biological aging. “This could take many forms. For example, approval of a drug that when given to healthy people acts as a preventative for several age-related diseases or indications.”

Researcher Jane Rylett recently returned from a trip to Japan, the world’s first “super-aged” country, defined as one in which more than one in five

people are 65 or older.

Canada will be a super-aged country in 10 to 15 years. The World Health Organization predicts that by 2050, there will be several dozen countries in that category, she said.

“Let’s say there was something on the horizon. Let’s say there’s a great discovery,” she said. “There are a lot of health policy questions that would have to be answered. What does it mean for society if people live longer?”