Sorry guys, whatever you are saying: cancer is a product of the cellular replication system and the faint, yet existing possibilities of errors in that system. To our best knowledge, the are mostly associated to DNA mutations and certain other physio-chemical states (e.g., epigenetics) associated to it. However, the longer you live, the more likely you will beceome prone to incur these genetic state changes. This state change is mostly related to the fact that we live longer than before. Obviously, there is hereditary cancer and all its implications and we can trace that, but the increased occurrence of these genetic issues leading to our cells to behave in discord in modern society is undoubtedly linked to the greatly increased lifespans. No scientific study has come up with other evidence - and if it would have, I can assure you it would be on the headlines of Science, Nature, and other scientific journals.
How would you explain that there are (or were) cultures completely or almost completely free of cancer - with it becoming more common when they adopted the western lifestyle?
In Cancer, Disease of Civilization (1960), Wilhjalmur Stefansson mentions a few cultures besides the Inuit in which large-scale searches never turned up cancer. Dr. Albert Schweitzer examined over 10,000 traditionally-living natives in Gabon (West Africa) in 1913 and did not find cancer. Later, it became common in the same population as they began "living more and more after the manner of the whites."
In Cancer, its Nature, Cause and Cure (1957), Dr. Alexander Berglas describes the search for cancer among natives in Brazil and Ecuador by Dr. Eugene Payne. He examined approximately 60,000 people over 25 years and found no evidence of cancer.
Well, in the modern world even school kids may have cancer - my daughter has a classmate who went through it, and that's primary school. I don't know the details though about type of cancer etc.
But those cultures didn't have cancer, din't have obesity, diabetes, heart disease ... I don't even know what diseases they died from.
I do not have the book "Cancer, Disease of Civilisation" and the blog post does not tell about the age. Here's the compilation of two other blog entries from the same blog:
One of these physicians was captain George B. Leavitt. He actively searched for cancer among the traditionally-living Inuit from 1885 to 1907. Along with his staff, he performed 50,000 examinations a year for the first 15 years, and 25,000 a year thereafter. He did not find a single case of cancer. At the same time, he was regularly diagnosing cancers among the crews of whaling ships and other Westernized populations. It's important to note two relevant facts about Inuit culture: first, their habit of going shirtless indoors. This would make visual inspection for external cancers very easy. Second, the Inuit generally had great faith in Western doctors and would consult them even for minor problems. Therefore, doctors in the arctic had ample opportunity to inspect them for cancer.
This entry does not mention lifespan, but the other one does:
Excluding infant mortality, about 25% of their population lived past 60. Based on these data, the approximate life expectancy (excluding infant mortality) of this Inuit population was 43.5 years. It's possible that life expectancy would have been higher before contact with the Russians, since they introduced a number of nasty diseases to which the Inuit were not resistant.
I do not have data at hand about cancer rates in the western world by age, but my guess would be that it's not so uncommon at the age of 60+.
1,301.6 per 100,000 in the 60- to 64-year-old population;
So, if that George B. Leavitt was indeed performing 50,000 examination per year (looks a bit high, that's over 100 per day), and 25% of inuit population lived past 60, he should have examined about 12,500 inuit aged 60+ per year.
By current western standards, he should have found about 160 cases each year among those 60+ guys. The book claims he has not found any.
Well then, I'd consider that to be one of those extraordinary claims that demands extraordinary evidence. Something other than hearsay from a dodgy-sounding source.
I'm trying to find out about this George B. Leavitt guy. I assume it was this guy:
but he wasn't a physician as claimed, he was a captain and it doesn't mention him having any medical training. Wikipedia also fails to say anything about him examining people for cancer -- if he were really doing so at the rate of one hundred and thirty six per day on average, in between his many other duties (like, say, captaining a whaling ship which would require quite a lot of time spent at sea) then one would think it would have been quite time-consuming.
Other googling for "George Leavitt Cancer" provides a few repetitions of the same claim (including this thread -- hi there!) but nothing that looks reputable. The original claim seems to come from a book called "Cancer: Disease of Civilization?" written by one Vilhjalmur Stefansson who travelled with Leavitt.
Also, your stats aren't quite right. Even if he were examining that many people, he wouldn't expect to detect cancer at nearly the rates that modern medicine would.
Also, that's the cancer incidence rate, not the rate at which you expect to find living people with detectable cancers, since people who do have cancer tend to die, especially in societies where they can't treat it. By the time a cancer becomes big enough to detect via a cursory examination with 19th century technology, it has probably already killed you.
So detectability, probably, was not that big of an issue itself.
Unless, of course, he got it into his head that Inuit didn't have cancers, and then started making false diagnoses based on that.
Look, I don't know how much of this story is true and how much of it is made up. Certainly the part where he's a trained physician seems to have been made up. The part where he examined fifty thousand Inuit plus a significant of westerners per year in between his actual duties as a ship's captain appears to be completely implausible. If this random anecdote is the best evidence we have that living with a traditional Eskimo diet will signficantly lower your chance of cancer, I think it's safe to say that the evidence for the hypothesis is pretty darn pissweak.
Average inuit lifespan is about 45 years - however, that means they had a higher life expectancy than we did before we surpassed them. So the extremely cold environment does seem to help (although you just won't get me there :)
we do accelerate this cellular replication however with the diets we are currently consuming. As we put our bodies into hyperinsulinism through eating the plethora of carbohydrates we do, we are essentially accelerating the amount of cell replication, increasing the chance an error occurs.
