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Most of the average lifespan increases we've seen have come from reduced infant and childbirth mortality, not from making the elderly live to be even more elder

Most of the average lifespan increases we've seen have come from reduced infant and childbirth mortality, not from making the elderly live to be even more elderly. There has certainly been some of that, but it's far less significant than the infant and childbirth mortality improvements. >Rowbotham and Clayton (JRSM 2008;101:454–62) make a very important point when they draw attention to the life expectancy at birth compared to life expectancy at 5+ years of age.1 They state ‘… life expectancy in the mid-Victorian period was not markedly different from what it is today. Once infant mortality is stripped out, life expectancy at 5 years was 75 for men and 73 for women.’ In 1995 Griffin2 produced a comparison of life expectancy of mature men (15+years of age) at different points in history over the last 3000 years >The change in life expectancy of mature men^ has not changed as dramatically over 3000 years as might be expected, although this data must of necessity refer to privileged members of society. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2625386/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2625386/ Note also that being economically or socially privileged would have given these men better access to nutrition, however it would have also given them better access to contemporary 'medicine' which may very well have been more hazardous to their health than no medical intervention at all. How many wealthy people in the past were poisoned by their well-meaning doctors? I'd wager more than were saved. ^ (The numbers for women are very different, because women used to frequently die during childbirth, but this is comparatively rare today.)

brandonmenc 8y ago
> Most of the average lifespan increases we've seen have come from reduced infant and childbirth mortality, not from making the elderly live to be even more elderly. You're missing my point. Lifespans are increasing. The reason why is irrelevant. Regardless, the result is that you have more time to accumulate irreversible damage than your ancestors did, so their habits re: the sources of that damage are not necessarily prescriptive. There's probably a hard limit on radiation exposure, and that means you'll have to spread it out more than your ancestors did to enjoy the same risk of cancer - ex: same number of hours in the sun but over a longer lifespan = shorter individual trips under the sun, but (inevitably) more of them.
- darkpuma 8y ago
  You've missed my point, the increases in human lifespans have come from greater success at reproduction (surviving childbirth, and surviving being a child long enough to reach sexual maturity), which is rather contrary to what you've suggested. Furthermore: > "As lifespans increase, so should efforts to avoid cumulative, damaging radiation." The elderly are not living much longer than they ever did before, so this is basically nonsense. It makes sense if you assume that 200 years ago men were dropping dead in their 40s like those naive life expectancy statistics would lead to to believe, but that's not what was going on. The life expectancy of a mature male has barely changed at all in the past few thousand years, so the relative importance of avoiding cumulative damage like radiation has not increased either.
  - brandonmenc 8y ago
    > naive life expectancy statistics Yes, we all know about that. You're getting too hung up on me saying "lifespans increase." Forget that I said that. Imagine I instead said, "we are optimizing for health in old age more than the ancients did." > the relative importance of avoiding cumulative damage like radiation has not increased either It wasn't important at all back then because they didn't know about it. Do you want to die in agony in your 70s from metastasized skin cancer, or peacefully in your sleep at 80? My point is that propagation of the species, old age, and rampant melanoma can all exist simultaneously - so what people did in the past re: sun exposure isn't necessarily good advice for us today.
owenversteeg 8y ago
Wow, 75 for men and 73 for women! That's crazy. I wonder why Wikipedia doesn't seem to indicate this on the otherwise comprehensive life expectancy page. I did find this fascinating and sad bit on that page though: "Actual life expectancy in Botswana declined from 65 in 1990 to 49 in 2000 before increasing to 66 in 2011. In South Africa, life expectancy was 63 in 1990, 57 in 2000, and 58 in 2011. And in Zimbabwe, life expectancy was 60 in 1990, 43 in 2000, and 54 in 2011." Apparently this is mainly due to HIV. I thought the effect would maybe bring down life expectancy down by 3 or 5 years, not 17 or 16. That's insane.

brandonmenc 8y ago

> Most of the average lifespan increases we've seen have come from reduced infant and childbirth mortality, not from making the elderly live to be even more elderly. You're missing my point. Lifespans are increasing. The reason why is irrelevant. Regardless, the result is that you have more time to accumulate irreversible damage than your ancestors did, so their habits re: the sources of that damage are not necessarily prescriptive. There's probably a hard limit on radiation exposure, and that means you'll have to spread it out more than your ancestors did to enjoy the same risk of cancer - ex: same number of hours in the sun but over a longer lifespan = shorter individual trips under the sun, but (inevitably) more of them.

darkpuma 8y ago
You've missed my point, the increases in human lifespans have come from greater success at reproduction (surviving childbirth, and surviving being a child long enough to reach sexual maturity), which is rather contrary to what you've suggested. Furthermore: > "As lifespans increase, so should efforts to avoid cumulative, damaging radiation." The elderly are not living much longer than they ever did before, so this is basically nonsense. It makes sense if you assume that 200 years ago men were dropping dead in their 40s like those naive life expectancy statistics would lead to to believe, but that's not what was going on. The life expectancy of a mature male has barely changed at all in the past few thousand years, so the relative importance of avoiding cumulative damage like radiation has not increased either.
- brandonmenc 8y ago
  > naive life expectancy statistics Yes, we all know about that. You're getting too hung up on me saying "lifespans increase." Forget that I said that. Imagine I instead said, "we are optimizing for health in old age more than the ancients did." > the relative importance of avoiding cumulative damage like radiation has not increased either It wasn't important at all back then because they didn't know about it. Do you want to die in agony in your 70s from metastasized skin cancer, or peacefully in your sleep at 80? My point is that propagation of the species, old age, and rampant melanoma can all exist simultaneously - so what people did in the past re: sun exposure isn't necessarily good advice for us today.

owenversteeg 8y ago

Wow, 75 for men and 73 for women! That's crazy. I wonder why Wikipedia doesn't seem to indicate this on the otherwise comprehensive life expectancy page. I did find this fascinating and sad bit on that page though: "Actual life expectancy in Botswana declined from 65 in 1990 to 49 in 2000 before increasing to 66 in 2011. In South Africa, life expectancy was 63 in 1990, 57 in 2000, and 58 in 2011. And in Zimbabwe, life expectancy was 60 in 1990, 43 in 2000, and 54 in 2011." Apparently this is mainly due to HIV. I thought the effect would maybe bring down life expectancy down by 3 or 5 years, not 17 or 16. That's insane.