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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?

#51

Post by _0w8t »

phonypc wrote: post #44
arnejenssen wrote: post #23

The modern age has possibly removed some carcinogens like inhaling smoke from (bon)fires, mycotoxins from spoilt food, nutritional illiteracy and unsanitary conditions. But the modern age has introduced a lot of new ones like tobacco, food additives, sugar, gluten, radiation, asbestos, industrial processing of food, pesticides, sedentary lifestyle.

Calling a lot of these things carcinogens is a little odd. It's not synonymous with harmful, and even harm isn't obvious for all of these. Food additives and processing in general? Gluten for people who tolerate it?

During the last 120 years wheat was optimized for machines making its gluten content higher that could explain higher gluten intolerance among people presently.

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

#52

Post by JohnJamesRambo »

titzer wrote: post #38
JohnJamesRambo wrote: post #11

Earlier quoted context omitted.

Last time I reviewed the glyphosate literature it wasn’t that impressive of a link between Roundup and cancer. Has anything changed? https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5705608/ I agree Monsanto is a horrible company, but for other reasons.

Did you actually read the article you linked? It is actually arguing that logic doesn't work. > Overall, a scrutiny of the method used in these commentaries by Samsel and Seneff reveals a major flaw. These authors employ a deductive reasoning approach based on syllogism, which is formed by two or more propositions used to generate a conclusion. The first proposition is generally related to glyphosate’s properties (e.…

I'm sorry, I don't see what you see in that article and I don't think you understand it either.

Graphs showing increased cancer risk since glyphosate was introduced is almost zero evidence that it does anything. Lot of other things have happened in that same time period such as increases in obesity, etc. The real way to study it is to give an animal glyphosate and see if it does anything to cancer rates.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4819582/

Evaluation of carcinogenic potential of the herbicide glyphosate, drawing on tumor incidence data from fourteen chronic/carcinogenicity rodent studies

"There was no evidence of a carcinogenic effect related to glyphosate treatment."

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

#53

Post by titzer »

JohnJamesRambo wrote: post #52
titzer wrote: post #38

Earlier quoted context omitted.

Did you actually read the article you linked? It is actually arguing that logic doesn't work. > Overall, a scrutiny of the method used in these commentaries by Samsel and Seneff reveals a major flaw. These authors employ a deductive reasoning approach based on syllogism, which is formed by two or more propositions used to generate a conclusion. The first proposition is generally related to glyphosate’s properties (e.…

I'm sorry, I don't see what you see in that article and I don't think you understand it either. Graphs showing increased cancer risk since glyphosate was introduced is almost zero evidence that it does anything. Lot of other things have happened in that same time period such as increases in obesity, etc. The real way to study it is to give an animal glyphosate and see if it does anything to cancer rates. https://www.…

You seem motivated to push a particular narrative and are cherry picking papers to support it, so I really don't want to go back and forth anymore about this, but here's a even larger meta-study that has a completely different conclusion.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7014589/

> The strongest evidence shows that glyphosate causes hemangiosarcomas, kidney tumors and malignant lymphomas in male CD-1 mice, hemangiomas and malignant lymphomas in female CD-1 mice, hemangiomas in female Swiss albino mice, kidney adenomas, liver adenomas, skin keratoacanthomas and skin basal cell tumors in male Sprague-Dawley rats, adrenal cortical carcinomas in female Sprague-Dawley rats and hepatocellular adenomas and skin keratocanthomas in male Wistar rats.

In fact, this paper links to some of the same studies that the paper you linked to also does, with different conclusions. In particular, it seems your paper was extremely selective about which cancers could be caused by glysophate, e.g. ignoring several types.

> Graphs showing increased cancer risk since glyphosate was introduced is almost zero evidence that it does anything.

That's just an absurd statement, so I'll disengage now.

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

#54

Post by lmilcin »

strken wrote: post #26
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?

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.

> A lot of the lower life expectancy was sky-high infant mortality

If that was true, then age composition would be roughly the same as is now, except for larger number of infants.

You could even argue that if you had weaker infants die, you should end up with statistically stronger adults than now and you should see people live to older age than now.

I don't want to say infant mortality rate wasn't high, I just want to say that it has nothing to do with the topic of the discussion.

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

#55

Post by adolph »

7952 wrote: post #28
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?

I think evolution plays a part in why older people are more prone. A debilitating illness in your teens is likely to stop you reproducing and is more likely to vanish. But a genetic trait for cancer later in life can get past on.

There must be some evolutionary fitting function that mutations serve that have prevented them from being selected out.

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

#56

Post by zackees »

sv40 is a cancer causing virus that contaminated 1/3rd of all polio vaccines.

From wikipedia: The discovery of SV40 revealed that between 1955 and 1963 around 90% of children and 60% of adults in the U.S. were inoculated with SV40-contaminated polio vaccines.

Link to studies: https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=sv40...

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

#57

Post by siggen »

7952 wrote: post #28
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?

I think evolution plays a part in why older people are more prone. A debilitating illness in your teens is likely to stop you reproducing and is more likely to vanish. But a genetic trait for cancer later in life can get past on.

Medawar effect

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

#58

Post by [deleted] »

strken wrote: post #26
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?

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.

[deleted]

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

#59

Post by [deleted] »

refactor_master wrote: post #34
arnejenssen wrote: post #23

The modern age has possibly removed some carcinogens like inhaling smoke from (bon)fires, mycotoxins from spoilt food, nutritional illiteracy and unsanitary conditions. But the modern age has introduced a lot of new ones like tobacco, food additives, sugar, gluten, radiation, asbestos, industrial processing of food, pesticides, sedentary lifestyle.

You lost me at gluten though.

[deleted]
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