The Question of a Limit to Human Life Span

There has been much discussion in the aging research community these past few years on the topic of whether or not there is a limit to human life span, and how one might even go about defining such a thing. While life spans are in a slow upward trend due to general improvements in medical technology, can this trend continue without end, or will it run into a roadblock? In essence this is a debate over what can be extracted from poor data, and which data is in fact poor. Since there are few extremely old people, and since verifying age becomes ever harder the further back one has to go to search for records, the data for human mortality at advanced ages is very open to interpretation and reinterpretation, highly dependent on statistical methodologies used, and opinions on reliability of various sources of data.

In a more practical sense, this is all a storm in a teacup. Obviously there are mechanisms at work that ensure that even the statistical outliers don't make it much past 120. Autopsies carried out on supercentenarians revealed transthyretin amyloidosis, and consequent heart failure, as the dominant cause of death. It is reasonable to hypothesize that this form of age-related damage ensures the effective upper limit on human life span - in the sense that there is no hard limit, but if critical organ dysfunction ensures that mortality rates are 50% yearly or higher, then the odds catch up pretty quickly.

Equally obviously, all of this is absolutely dependent on the present state of medical technology. If transthyretin amyloid can be broken down, such as via the theraputic approach developed by Covalent Bioscience, then the result will be that everyone who periodically undergoes the treatment will live longer. The same goes for clearance of senescent cells, and all the rest of the SENS program of ways to repair the causes of aging. If medical technology addresses the damage of aging, then the length of life changes.

A related topic is the question of whether or not mortality rates stop increasing in very late life. Studies show that extremely old flies stop aging, in the sense that aging is defined as an increase in mortality rate per unit time. The flies have very high mortality rates, as is fitting for being in very poor shape, burdened by the damage of aging, but those very high rates appear to plateau. Over the past fifteen years, various analyses have suggested and then refuted that such a plateau exists in humans. Again we come back to the point that the data for very advanced ages isn't all that great, and so there tends to be a great deal of debate. At present, the balance of evidence and argument suggests that, for our species at least, mortality rates do keep increasing past the age of 110.

Are We Approaching a Biological Limit to Human Longevity?

Until recently human longevity records continued to grow in history, with no indication of approaching a hypothetical longevity limit. Also, earlier studies found that age-specific death rates cease to increase at advanced ages (mortality plateau) suggesting the absence of fixed limit to longevity too. In this study we re-examine both claims with more recent and reliable data on supercentenarians (persons aged 110 years and over).

We found that despite a dramatic historical increase in the number of supercentenarians, further growth of human longevity records in subsequent birth cohorts slowed down significantly and almost stopped for those born after 1879. We also found an exponential acceleration of age-specific death rates for persons older than 113 years in more recent data. Slowing down the historical progress in maximum reported age at death and accelerated growth of age-specific death rates after age 113 years in recent birth cohorts may indicate the need for more conservative estimates for future longevity records unless a scientific breakthrough in delaying aging would happen.

Many gerontologists are now more conservative regarding the future growth of longevity, citing results confirm that further growth of maximum lifespan for humans becomes an increasingly difficult task. Still there are reasons for cautious optimism here. Systematic analysis of human mortality throughout the 20th century revealed that, once a particular cause of death is accounted for, there is a proportional increase in both median age of death and maximum life span. So the authors of this study believe that application of aging-focused interventions could result in a continued increase not only in the median, but in maximal life span in humans as well.

Further research is needed to overcome obvious limitations of our study by addressing remaining concerns about data quality and representativeness, as well as increasing sample sizes. Still the data used in our study are the best available data so far, and their analysis suggests that there may be a provisional limit to human life in our current state of biomedical knowledge.

Comments

Hey there! Jsut a 2 cents.

''While life spans are in a slow upward trend due to general improvements in medical technology, can this trend continue without end, or will it run into a roadblock?''

Barring the idea that we entirely replace the body from new 3D printed organs or have infinite surplus of lab made fetal stem cell rebuild you in entirety or that we are capable or reverse the epigenetic age of cells in all cells, then, yes we run into a roadblock. [New Organs or stem cells may not save us, but epigenetic reprogramming might].

It is imopssisble for a old human to Not run into this roadblock. LEV is impossible as 'old person' (if excluding the above, especially if excluding epigenetic reprogramming), an old person Must revert to a young body; if not, will hit roadblock, sooner or later, before 120 or so. LEV can only be achieved by staying as a young body, in perpetuity.

Supercentenarians - were Younger biologically whole life (up to 8 years by horvath/hannum epiclock)....it'S why they reached so (vs other younger people who died at 80 or 90).

As the study said, after 113, there is great acceleration - it's obvious, the telomeres are so small now...no more left. When you are very old about 110, the 'junk' overtakes you from the life cumul...such as transthyretin brown pigment in heart...if you are Younger Biologically - then no, transthyretin wil Not accumulate - this was shown in ultra long lived animals who lived Much Longer than super centenarians..yes, in humans, it kills us...but that is only becaus a Super Centenarian is still very much damages/accumulated too much - Because they 'age' in that late point - it'S bs to say they don't age. They Still age. That study on flies not aging because of mortality plateau is bs/statistically wrong - flies, like humans, in the mitos still accrue elevation of ROS - with age - until death. It's why, later, other studies 'refuted' the saying that there is no aging 'in late life'. It's wrong. there is until you die at 12 or 120 (in humans, at least, that is). thus they are correct in refuting there is no aging later for human.

Our telomeres do not rise like an albatros or stay frozen like a naked mole rat (because we have net loss). We just experience much slower telomere shortening rate due to much better oxidative stress resistance, repair mechanisms and redox preservation. While the former may die simply due to predation, nothing related to their telomere 'non'-(bio)aging.

''Many gerontologists are now more conservative regarding the future growth of longevity, citing results confirm that further growth of maximum lifespan for humans becomes an increasingly difficult task...So the authors of this study believe that application of aging-focused interventions could result in a continued increase not only in the median, but in maximal life span in humans as well.''

Yes, it's understandable, if you don't do anything...indeed, we hit the proverbial roadblock - 120.
But, if we REVERSE ourselves to a young body, repeatedly - all this doubt will subside because it is the Only way to go above Maximum Lifespan. It was proven when animals that live long lifespans, they live long lifespans Because they are Biologically Young(er) Whole Life.

''If medical technology addresses the damage of aging, then the length of life changes. '' Exactly, I believe that too, but it needs to adress specific concerns and only if addresses them will we see lifespan extension Above maximum...average lifespan extension..is going to happen...but maximum, almost sure won't happen much - hit the 122 RoadBlock once again.
You Only go above that RoadBlock if you are biologically younger Before (reaching it)/whole life.

That old people could go Above roadblock is hard to believe - as said, maybe organ replacing/stem cell injection or epireprogramming could allow an very old person to go above roadblock - Because he/she REVERTS to young body (new young organs/new 'fetal young' stem cells making new young tissue/Epireprogramming to a fetal cell point - Age 0 epiclock). Thus, there is No Way out of it, you can only outdo the roadblock/MLSP if you 'deage' to a young(er) age/body. And telomeres Must Absolutely go back to size of young body - it cannot just linger/continue shrinking on and on (short telomere = death; supercentenarians = 2-3kb short telomeres = roadblock ahead - 122 MLSP (excluding the transthyretin problem added on top, which Assures you don'T go over roadblock)).
LEV is only possible this way.

Just a 2 cents.

Posted by: CANanonymity at July 12th, 2019 9:44 PM

"Cautiously optimistic" they say.

Posted by: Anonymoose at July 13th, 2019 4:42 AM

This has only academic interest. Its predictive power is nil.

Posted by: Antonio at July 13th, 2019 8:54 AM

There is an absolute roadblock on human longevity at 110 to 120 years. The only way to smash through that roadblock is to change the species. We humans need to evolve into something different. Our metabolism needs to be radically altered so that we decline or "age" at a much slower rate.

Or not at all. Humans need to mutate so that when an old cell dies out, and is replaced with a new one, the new one is 100% as good, or better, than the one it replaced. Then biological immortality will be achieved.

Posted by: Zan at July 14th, 2019 8:12 AM

In the 19th century, famous scientists told that train could never go faster than 100 km/h. They created a limit from belief, not from science. I believe this is the same for aging. Of course nobody will be 125 or 130 because there is no anti-aging therapies as of 2019. The first 130 yeard old will happen in the 2050s.

Posted by: Jonathan Weaver at July 14th, 2019 5:43 PM

@Jonathan Weaver
Exactly.
The oldest confirmed person aloive is about 115. So even if we had a proven anti-aging therapy today it would take at least 15 years. And supercentarians are so frail that their mortality is so that unless they rejuvenate the chances of living another 15 years are small even the person stops aging.

On to of that that person probably will not use the first therapies which might turn to be too toxic for someone over 110. I think that if we have the first generation of senolitics in 5 years (confirmed with good protocols) the first centarians to use them wild be at most 105. In 5 years. So those people should be about 100 now. So to have somebody reaching 130 we will need 30 years from now. In the best case scenario

Posted by: Cuberat at July 14th, 2019 7:54 PM

There about 70 000 centarians Alpine in US alone. However, between 150 and 600 super centarians (110 y). Basically it cold be as bad as 1 in thousand centarians reaching 110. Now we don't know how well the first therapies cold work. If the therapies have similar actuarial profile to calorie restriction then we will see the increase in health span and more people reaching 100 years. So even more will reach 110, 115 and increase the chances of breaking the 125 years wall. Unfortunately we will know that only after the there's have been around for a couple of decades.

Posted by: Cuberat at July 14th, 2019 8:12 PM

@David Permisov I agree with you. and this is the case for CR on so many levels, as we have seen hard proof in primates that restricting calories didn't do anything to their longevity, although it did improve health, and this shows that CR is likely to do nothing for humans, yet people still tout it as the holy grail of anti aging strategies.

Posted by: scott emptage at July 15th, 2019 7:20 AM

this debate has been alive and well for a long time. first of all there is no real evidence that humans have a "magic wall of death" if we can develop the right technologies to repair and reprogramme our cells etc. the fact of the matter is that we don't yet have these therapies so ATM all we can do is argue if there is or isn't a programmed time bomb in our bodies. hopefully one day we can all look back and laugh at the "wall of death" brigade lol

Posted by: scott emptage at July 15th, 2019 7:25 AM

@Zan good luck with that lol

Posted by: scott emptage at July 15th, 2019 7:26 AM

Ref Novartis
,>The failure is a blow to the hypothesis that anti-amyloid drugs delay or prevent the onset of Alzheimer's when given before patients develop symptoms.

It seems that amyloid build up servers some perceive function when faced with chronic infection. Out is like saying that police on the crime scene correlates with crime and trying to reduce the crime by inhibiting police reaction. That might help to an extent when they are overzelous but is not long term solution.

I think there is a bunch of drugs in the pipeline for slots left amyloid reduction. So in the next 2-5 years we will see this kind of news were the drugs fail. Bus since they're is still how that one of them might work the Pharma companies keep the research on to justify the sunk cost.

Posted by: Cuberat at July 15th, 2019 8:35 AM

@Cuberat: Introducing small amounts of misfolded A-beta into mice brains causes more misfolding, neuron death and cognitive decline. OTOH, that doesn't mean that it's the only cause.

Posted by: Antonio at July 15th, 2019 10:48 AM

@Antonio
Good point.

Posted by: Cuberat at July 15th, 2019 12:46 PM

Somewhere in the real world once people get past 65 yrs...they statistically have another 20 yrs...to around 85 or so...when 50% of the people their age will be dead.

While I take quite a few supplements and try at least to protect my health....I've watched my mother wither away as she ages so at her mid 90's she is sort of a physical/mental/emotional ghost of her former self.

I'm not being negative just realistic (?) and am watching myself generally deteriorate to some degree as I get older.

Some I know hug one another and pray to their invisible protectors...which I see and observe...while I try at least to slow the decline in other ways. I've seen them tend to revert to old ways and prejudices...seems that they just stop growing after 65 or so....tend to group together and reinforce the "getting older" traditions of the forebears. (Goldilocks and the 3?)

Hopefully I can keep my mind reasonably sharp and stay physically mobile...so who knows. Eventually as I deteriorate I might adopt more of those old people ways.

Keep working on them magic pills though....

Posted by: harry at July 17th, 2019 3:33 AM

@harry your remarks are based on a situation where we don't yet have the therapies to combat aging, once we get senolytics etc we will see profound changes in health of older people

Posted by: scott emptage at July 17th, 2019 3:46 AM

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