Hoping to reach 100? You’re not going to like these new life expectancy projections

[Dr.Bart]

@CronosTempi

I thought it was a pretty uncontroversial statement, but OK. Mice in the wild are subject to heavy predation. Predation and a variety of accidents is the #1 cause of death for mice by a wide margin in their natural environment, whereas for humans that’s pretty far down the list. Which means that a lab is going to be far more protective for a mouse than a human. Humans “in the wild” had it pretty rough, as Hobbes put it, lives that were nasty, brutish and (ahem!) short. Which is what a mouse has in the wild. But humans developed civilization (something mice should try!) and today, at least in developed countries, our environment is not far away in safety and convenience than what you can get in a lab, so you are not getting much of a jump in longevity transferring a human to a lab compared to a mouse to a lab. There are countless advantages to a modern human environment, note the massive jump in longevity achieved by the introduction of convenient hygiene and sewage/plumbing. The hygiene arrangements for mice in the wild are deplorable. We can complain about the healthcare system, especially in the USA, but look at what wild mice get - if a mouse falls sick, becomes frail and cannot run as fast, the first healthcare intervention is from Dr. Owl, whose patients, spoiler alert, inconveniently always end up dead on the operating table. The necessity to engage in risky foraging for food, with no assurance of consistency or quality is something mice face daily, whereas the days of humans fighting off lions and hyenas for scraps has been abolished by civilization. A lab is a huge boon in this respect for wild mice compared to humans who in their environment have access to nutrition with little risk and effort.

But the dead giveaway of the vast chasm between wild and lab for a mouse vs human in his civilized environment and a lab is one simple fact: mice almost never reach advanced old age in the wild, whereas they regularly do so in a lab. The moment a mouse falters whether by illness or first whiff of age-related disability, they cannot survive in the highly competitive and hostile environment. So they almost never get the chance to be old and frail and putter along. A lab, is a godsend and paradise in comparison. Humans by contrast, by their majorities reach old age and many very advanced old age right in their civilized environment of developed countries. Mice have much more to gain by being in a lab than a human would - like in at least reaching old age; humans reach old age, and extreme old age just fine outside a lab.

And how do we know that our developed world enviroment is almost as good as a lab for a human? Because we see that by the evidence in animals. A feral cat in an urban environment lives longer on average than in the wild as their food supply is often supplemented by humans and they are less subject to predation, but yet, an urban feral cat lives on average only about 6 years or so. Meanwhile the same species of cat, in the human environment as a pet, with protection, access to quality food and vet care, live 15 years, or more than twice as long, and regularly even 20+. They share our environment, our homes, and they max out their lifespans - they don’t gain much if anything in lifespan from being put in labs, and we have those stats. It’s not like cats break longevity records in labs the way mice do. Our human environment in developed countries is pretty optimized for human lifespan, because that’s what civilization has focused on for thousands of years - prolonging life, minimizing risk, upping the quality and convenience. A feral cat - 6 years, a cat pet in human environment 15-20, or a boost of 200%-400%. Putting a human in a lab is not going to give us a 200%-400% boost in longevity, because our civilized environment is already pretty human adapted. Which is why my uncontroversial statement was that mice have vastly more to gain from a lab than a human. We die in old age, often extreme age, wild animals rarely do.

That’s a nice hypothesis but that’s not evidence. True scientists always question outdated axioms. Your whole argument is anchored on an assumption that we know what the is the human limit, but until you can perform the actual experiment (which will never happen obviously) you really don’t know, do you? You just cling to this unproven idea and rationalize it any way you can.
Humans may not have the traditional animal predators that mice have, but we are exposed daily to pollutants, toxins, irritants, infectious agents, stress and other non-traditional “predators”. How do you know if the humans were in a controlled laboratory settings FREE of all those agents, if they would not achieve a much higher life span?

[Dr.Bart]

@CronosTempi

Wrt. microbes. No doubt there is microbe related morbidity and mortality. But my contention is that microbes are not the primary driver of the rate of aging. If you eliminated all microbes, humans would not suddenly age more slowly. Look at that chart posted by RapAdmin a few posts up - Hallmarks of Aging. How many of those do you think are affected to any great degree by microbes? Dysbiosis - OK… which incidentally is a consequence of aging not as much a cause of aging as immune senescence makes us vulnerable to disbiosis. Otherwise it’s hard to see where in these hallmarks of aging microbes have any substantive role: stem cell exhaustion, genomic instability, loss of proteostasis, telomere attrition, altered intercellular communication, disabled macroautophagy, mitochondrial dysfunction, cellular senescence, chronic inflammation. We started this discussion over whether lifestyle interventions that you outlined can slow the rate of aging to give us 130-150 lifespans. I don’t think microbes measurably affect the rate of aging. Healthspan - sure. Lifespan - I can’t see it.

Actually microbial infections can induce many of those states. Here is just one example. I don’t want go on forever.

Possible Pathogenesis and Prevention of Long COVID: SARS-CoV-2-Induced Mitochondrial Disorder

Tsung-Hsien Chen,1 Chia-Jung Chang,2,* and Peir-Haur Hung1,3,*

João R. Mesquita, Academic Editor

Author information Article notes Copyright and License information PMC Disclaimer

Associated Data

Data Availability Statement

Go to:

Abstract

Patients who have recovered from coronavirus disease 2019 (COVID-19) infection may experience chronic fatigue when exercising, despite no obvious heart or lung abnormalities. The present lack of effective treatments makes managing long COVID a major challenge. One of the underlying mechanisms of long COVID may be mitochondrial dysfunction. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections can alter the mitochondria responsible for energy production in cells. This alteration leads to mitochondrial dysfunction which, in turn, increases oxidative stress. Ultimately, this results in a loss of mitochondrial integrity and cell death. Moreover, viral proteins can bind to mitochondrial complexes, disrupting mitochondrial function and causing the immune cells to over-react. This over-reaction leads to inflammation and potentially long COVID symptoms. It is important to note that the roles of mitochondrial damage and inflammatory responses caused by SARS-CoV-2 in the development of long COVID are still being elucidated. Targeting mitochondrial function may provide promising new clinical approaches for long-COVID patients; however, further studies are needed to evaluate the safety and efficacy of such approaches.

[DeStrider]

The number of centenarians in Hong Kong has almost doubled in the past two decades. That’s not genes. They rank 4th globally. Japan is the king at 76.5 centenarians per 100,000 residents. India is the worst at 2.1 centenarians per 100,000 residents. The USA has 25 centenarians per 100,000 residents.

It found that Hong Kong, whose centenarian population rose by about 90 percent in those two decades, was home to an estimated 3,561 centenarians in 2020 or 47 super seniors for every 100,000 residents.

After comparing assessments with other countries, the researchers found that Hong Kong’s longevity is attributed to its low mortality rate for cardiovascular diseases in men and women.

HK's hearty longevity edge | The Standard.

The United Nations estimated that there were 316,600 living centenarians worldwide in 2012, and 573,000 in 2020, almost quadruple the 2000 estimate of 151,000.

Centenarian

It seems lifespans have not increased since ancient times until the post-WWII era if you exclude child and infant mortality.

A survey of the lifespans of male individuals with entries in the Oxford Classical Dictionary (i.e., a sample pre-selected to include those who lived long enough to attain historical notability) found a median lifespan of 72 years, and a range of 32 to 107 years, for 128 individuals born before 100 BC (though the same study found a median lifespan of 66 years for 100 individuals born after 100 BC but no later than 602 AD); by comparison, male individuals listed in Chambers Biographical Dictionary who died between 1900 and 1949 had a median lifespan of 71.5 years, with a range between 29 and 105 years.

[RapMet]

@DeStrider

The number of centenarians in Hong Kong has almost doubled in the past two decades. That’s not genes. They rank 4th globally. Japan is the king at 76.5 centenarians per 100,000 residents. India is the worst at 2.1 centenarians per 100,000 residents. The USA has 25 centenarians per 100,000 residents

I find the number per 100k confusing and even irrelevant since that doesn’t takes into account the average age for that nation. As an example, if the national average age for a country is 30 of course there wouldn’t be many centenarians (as a % or out of 100k) in that country since MOST of their people were born in last 50 years. Whereas a country with an average age of 60 there’s got to be way more centenarians as a percentage of population.
A more precise number would be the percentage of people that make it to 100, let’s say how many people were born in 1924, and how many of them (as a percentage, or out of 100000) are alive today. Any other measure is somewhat misleading.

[RapAdmin]

The Probability of Us Living to Be Much Older?