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Was cancer less likely in a pre-industrial world?

nationalgeographic.com

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Re: Was cancer less likely in a pre-industrial world?

#121

Post by dsjoerg »

Sebb767 wrote: post #12

One thing which I always thought of, but which the article doesn't mention, is age. Especially older people seem more prone to cancer, so in my mind a lower life expectancy will naturally lead to a lower cancer rate, as people die before cancer "is able to get them". Or am I missing something?

Your objection is correct, and none of the responses you've received so far seem to have understood your point. I went ahead and read the actual published paper (https://acsjournals.onlinelibrary.wiley.com/doi/epdf/10.1002...) and it is just as statistically naive as the NatGeo article made it sound.

Let's cartoonishly oversimplify cancer so that we can see how life expectancy would affect observed statistics. Let's say cancer occurrence is 0% for people up to age 40, and then starting on the 40th birthday, cancer occurrence is 10% per year. Everyone who gets cancer dies immediately.

Then, imagine that life expectancy in 1500 was 25 years old, standard deviation 10 years (yeah lognormal blah blah just go with it). So, most people don't live to 40, but the ones who do sometimes get cancer.

But then, after 1500, life expectancy mean increases by 0.1 years per year. By the year 2000, life expectancy is 75 years old! Much more cancer is going to happen! Many more of the deaths will be from cancer!

Cancer itself didn't change.

So, these researchers see a lower cancer rate in the bones they're looking at, but they need to do some MATH on the ages these bones and of modern humans to know how to compare cancer rates then to cancer rates now.

Re: Was cancer less likely in a pre-industrial world?

#122

Post by pharrington »

throwaway12319 wrote: post #79
bryanmgreen wrote: post #60

Probably a dumb question, but I’ve wondered if plastic has anything to do with cancer in the modern era? Mostly everything we consume these days has been touched by a form of plastic.

There's very extensive documentation on the carcinogenic effect of microplastic and atmospheric particulate. It's not a debated issue: it's well known.

This presentation[1] from two years ago says two monomers used in different microplastics are known to be carcinogenic (ethylene oxide and vinyl chloride) - other monomers might be, and the polymers themselves weren't known to be carcinogenic. Do you have some more up-to-date sources ?

[1]https://cues.rutgers.edu/2019-microplastics-conference/pdfs/...

Re: Was cancer less likely in a pre-industrial world?

#123

Post by Aerroon »

CoryAlexMartin wrote: post #77
mikewarot wrote: post #75

When I saw a great^n grandmother's 1870 census entry, which said she had 7 children, 1 of which was still alive (at 55), the reality of life back then hit me hard. This a meaningless question for most people, if it helps save lives in the future, great. I think you should also pay attention to Bret Weinstein's work on telomeres and cancer. If the environmental pressures are for a low age, you end up with long telomer…

Are our telomeres long enough to allow for the development of cancer, or is it necessary for the system to be overridden, thus allowing cells to replicate indefinitely? My layman's understanding was that benign moles were benign, and not cancerous, because the telomere system was functioning normally and limiting growth. Am I wrong?

>Are our telomeres long enough to allow for the development of cancer, or is it necessary for the system to be overridden, thus allowing cells to replicate indefinitely?

I'm not sure that it's actually telomere length itself that's the factor. I think it's more about telomerase.

Telomerase is the enzyme that lengthens telomeres. In cancer cells telomerase production is (usually) upregulated. This leads to cancer cells being able to continue dividing without telomere shortening being a problem.

However, this is just a guess. I'm not clear on the details of the processes.

Re: Was cancer less likely in a pre-industrial world?

#124

Post by zabzonk »

Kejiti wrote: post #104
tejtm wrote: post #87

Earlier quoted context omitted.

Not a biologist, but been around them long enough. I been cultivating a theory that mammals strategy is more or less "go fast; break things". That is, asteroid or not, we were on track to out evolve everything that came before by extending and exploiting explosive cell growth. No animal converts matter & energy to body-mass faster than young mammals, the cold blooded do not stand a chance. The competition would get l…

We humans are very unique though on how much care and dependency babes need. From an evolutionary perspective natur might have just stoped after we gave birth but for humans you need to be still very healthy for much longer. We have a second evolution which we as a species gained due to our more generic and bigger brain and therefore being able to retain and learn more even through generations. Whenever nature stoped…

All mammals care for their offspring - it's what makes them mammals. Many of them do it for quite big chunks of the parent's own lives.

Re: Was cancer less likely in a pre-industrial world?

#125

Post by reader_mode »

CyanBird wrote: post #106
tejtm wrote: post #87

Earlier quoted context omitted.

Not a biologist, but been around them long enough. I been cultivating a theory that mammals strategy is more or less "go fast; break things". That is, asteroid or not, we were on track to out evolve everything that came before by extending and exploiting explosive cell growth. No animal converts matter & energy to body-mass faster than young mammals, the cold blooded do not stand a chance. The competition would get l…

I think it is a cute hypothesis, but I don't believe it is fully functional, how would this explain megafauna? An I am not talking of moose, but of ice age gigantic mammals, which were just gigantic

They are extinct, so supporting his hypothesis ? It's not like evolution is a design process in which something gets "traded off" - random shit happens, something sticks.

Re: Was cancer less likely in a pre-industrial world?

#126

Post by GekkePrutser »

I think it was mainly less likely because people were so much more likely to die of other causes, so they'd die before the cancer got a chance. Healthcare was at its most basic and out of reach for common people.

I'm sure some of our environmental issues make cancer more likely. But we shouldn't imagine that the pre-industrial world was super healthy. People were living in filth. This was in fact one of the reasons they died so soon.

It's also one of the few things we haven't really found a cure for. I think because each cancer is a different random genetic mutation that would benefit the most from a custom generated antibody or something. Whereas other major causes of death have been pretty much eradicated by things like antibiotics and vaccines. So I think this makes the numbers relatively higher.

And of course because healthcare was so poor, I'm sure there would also be many causes of death misattributed. Even in this day and age we can't seem to standardise it. Some countries attribute every death to coronavirus if the person was infected, others only if it was 100% certain to be the cause of death.

Re: Was cancer less likely in a pre-industrial world?

#127

Post by mlac »

GekkePrutser wrote: post #126

I think it was mainly less likely because people were so much more likely to die of other causes, so they'd die before the cancer got a chance. Healthcare was at its most basic and out of reach for common people. I'm sure some of our environmental issues make cancer more likely. But we shouldn't imagine that the pre-industrial world was super healthy. People were living in filth. This was in fact one of the reasons t…

I’d hazard a guess that a lot more people also died of “natural causes“. Unless you cut someone open, the way cancer actually kills you (organs shutting down, trouble breathing, etc) would be described as “natural causes” or getting old and dying…

Re: Was cancer less likely in a pre-industrial world?

#128

Post by [deleted] »

okaram wrote: post #105
strken wrote: post #26

Earlier quoted context omitted.

Perhaps they control for age? A lot of the lower life expectancy was sky-high infant mortality, and if you made it to 10 in 1850 (hardly preindustrial, but preindustrial stats are harder to find) you could expect to live to 60 or so. Presumably you'd compare the cancer rates of your study's skeletons with the cancer rates of today's 60 year olds.

I don't have data, but I assume that is only for rich males? Maternity mortality rates were horrible, wars etc

[deleted]

Re: Was cancer less likely in a pre-industrial world?

#129

Post by underwater »

dsjoerg wrote: post #121
Sebb767 wrote: post #12

One thing which I always thought of, but which the article doesn't mention, is age. Especially older people seem more prone to cancer, so in my mind a lower life expectancy will naturally lead to a lower cancer rate, as people die before cancer "is able to get them". Or am I missing something?

Your objection is correct, and none of the responses you've received so far seem to have understood your point. I went ahead and read the actual published paper ( https://acsjournals.onlinelibrary.wiley.com/doi/epdf/10.1002... ) and it is just as statistically naive as the NatGeo article made it sound. Let's cartoonishly oversimplify cancer so that we can see how life expectancy would affect observed statistics. Let'…

Life expectancy in the 1500s was much higher if you discard infant mortality. Like 55 years, not 25.

Re: Was cancer less likely in a pre-industrial world?

#130

Post by zdragnar »

underwater wrote: post #129
dsjoerg wrote: post #121

Earlier quoted context omitted.

Your objection is correct, and none of the responses you've received so far seem to have understood your point. I went ahead and read the actual published paper ( https://acsjournals.onlinelibrary.wiley.com/doi/epdf/10.1002... ) and it is just as statistically naive as the NatGeo article made it sound. Let's cartoonishly oversimplify cancer so that we can see how life expectancy would affect observed statistics. Let'…

Life expectancy in the 1500s was much higher if you discard infant mortality. Like 55 years, not 25.

Cancer rate after 40 is also not 10% per year. It is a reasonable simplification to demonstrate the point.
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