Has the First 200 Year Old Already Been Born? Part I

by | Jul 14, 2021

This question has been the subject of thousands of scientific articles, books and movies over the years, but given the doubling of human life expectancy over the last century and a half and recent advances in medicine, it’s a legitimate question today. The answer has profound implications for multiple industries–including and especially life settlements.

I’ve been directly involved in this debate for the last three decades, beginning with a lead article in the top scientific journal Science back in 1990 where my colleagues and I estimated that the upper limit to human life expectancy was about 85 years (88 for women and 82 for men). Going beyond that will require manipulating the biological processes of aging. Lifespans must of course be much higher than this in order to get the population averaging metric of life expectancy to rise this high, but for reasons that I’ll explain, lifespans of 150 or even 200 as others have speculated, cannot realistically happen any time soon.

In other words, the conclusions we arrived at in our 1990 article about the upper limits to human longevity were stated correctly more than three decades ago, and nothing has changed since then, but the debate certainly continues to this day.

The online site Pairagraph sponsored a debate on this topic between one of the world’s leading evolutionary biologists, Dr. Tom Kirkwood, and myself on the question of whether the first 200-year-old person is currently alive–This is not a question about whether someone alive today is 200 years old; but whether anyone alive today will live to their 200th birthday many years from now. Part I of the debate appears below, which is the first exchange that took place between Kirkwood and myself; Part II will be published in a separate newsletter. The essays are short because we were each allowed only 500 words to state our case.

Dr. Tom Kirkwood

Newcastle University

Our question is about a matter of fact and must, in time, be answerable with a plain ‘yes’ or ‘no’. The oldest verified person living today – the current front-runner in the longevity race – is Kane Tanaka, who was born in Fukuoka, Japan, on January 2, 1903. She is 118 years old. If Kane Tanaka survives to age 200, making the answer ‘yes’, this will be in the year 2103. If she fails, but someone else does it, we must wait a bit longer. If no one has done it by 2221, the answer will be ‘no’.

Clearly, a definitive answer is going to take a while. However, can we get some idea of the likelihood of a yes/no answer in other ways? There are three things at least we can consider. Firstly, could it happen just by chance? Realistically, Kane Tanaka’s statistical chance of surviving even to her next birthday, given recorded mortality rates among supercentenarians, is no better than 50:50. To do it 81 more times beyond this is unimaginable.

The next possibility arises from what history has taught us about human longevity. Over the last two centuries, in the USA and other high-income countries, the average length of human life has doubled. To reach 200 is effectively to double it again. To acquire further insight, we need to look beneath the hood of the longevity engine.

From around 1800 to the mid-20th century, we gained life expectancy through reducing the death rates in the early and middle years of life, chiefly by control of infections through hygiene, vaccination and antibiotics.

By the late 20th century, there was little room to improve further in this regard, but life expectancy carried on growing at the same rate as before, only this time it was because older people were dying less. This told us something new: the aging process is more malleable than had been thought. Nevertheless, although the average lifespan continued to grow – at a rate over 2 years per decade – the lifespans of the longest-living individuals have remained stubbornly static. Might this indicate a limit?

We now turn to biology. Could our burgeoning knowledge of the underlying mechanisms of aging open paths to modifying the intrinsic processes that drive the body into decline? Most experts now agree there is no program that actively causes us to age and die. On the contrary, our bodies are programmed for survival not death. The reason we do not live forever is that evolution had higher priorities than wasting energy on better maintenance of our bodies than was needed in our ancestral ‘wild’ environment, where many things were likely to kill us relatively young.

The science of aging has a buzz that excites many with the possibilities that may lie ahead. We would be working with the grain of our biology, rather than against it, in trying to enhance survival, so can we boost our maintenance systems to deliver longer, healthier lives? It ought to be possible, but when?

Dr. S. Jay Olshansky

Lapetus Solutions and University of Illinois at Chicago

Twenty-one years ago, Steven Austad and I initiated a wager — would anyone alive in the year 2000 still be alive in the year 2150. I said no; Steven said yes. This wager made its way through aging circles and subsequently led to the launch of Longbets. Neither Steven nor I will be alive in 2150 to collect the $1 billion winnings. We will both be long gone, and we know it.

Why are we certain we won’t be alive in 2150? The answer is simple. Living things like mice, dogs, fruit flies, sharks, elephants, and yes, humans, exhibit unique but highly consistent patterns of death that map perfectly with age. I call this a “species-specific mortality signature”. These signatures do not change, even when the age-specific risk of death declines across time, as is the case with humans.

The ‘signature’ is a byproduct of fixed genetic programs for growth, development, and reproduction that evolved under the direct force of natural selection; and these genetic programs, in turn, are byproducts of the level of hostility in the environment when each species arose. As Dr. Kirkwood noted, aging and death cannot be programmed into our genome because such programs would be exhibited in age windows late in life when the force of selection is at or near zero. Aging and death are therefore inadvertent byproducts of fixed genetic programs that exist for another purpose — reproduction.

The disposable soma theory of senescence devised by Dr. Kirkwood explains why it would be a waste of energy to favor immortality — or a 200-year lifespan for humans — so lifespans are inherently limited. Steven Austad, Tom Kirkwood, and I all know this.

Under current conditions, the answer to the question raised here is a definitive no!

The only pinpoint of light that makes a 200-year lifespan remotely possible is the absence of aging and death programs. This means aging is inherently modifiable; it has already been experimentally modified in other species; and there is reason to expect aging will eventually be slowed in humans.

The problem with speculation that someone alive today will live to 200 is that the number itself is made up — we might as well be contemplating lifespans of 1,000 years, 5,000 years, or immortality for that matter. Even if an aging intervention was developed, there would be no scientific way to verify its effect on maximum or average lifespan in humans. This would require an experiment that would take longer than the lifespan of those doing the research.

In short, there is no historical or current mortality record suggesting 200 is plausible; there are no medical or other interventions available today documented to dramatically extend maximum lifespan by multiple decades; there is no biological basis for concluding a 200-year lifespan is even conceivable; and most importantly, there is no empirical way of testing the hypothesis that an aging intervention — even if developed — would yield a maximum lifespan of 200.