I know of no studies but it is well-known that
- life expectancy has increased drastically since ancient Egypt and that
- cancer prevalence increases with age.
About the first point, life expectancy in ancient Egyptlife expectancy in ancient Egypt was around 25 years, and even in the middle ages no more than 30 years. Compare that to today’s 67 years. Granted, once you take infant mortality out of the equation life expectancy grows – but it still was much less than today, and more importantly, it was often less than 50 yearsit was often less than 50 years.
The second point is due to a number of factors but it all boils down to cell aging and accumulating effects of detriment mutations. There are occurrences of cancer in young people and even in children, but mostly, it is “a disease found in people over the age of 50a disease found in people over the age of 50”: according to SEER dataSEER data, just 95 people below 50 get cancer for 1449 incidences above 50.
Combined, it isn’t surprising to see that cancer is much more common now than it was then. Superficially, no further reasons are needed to explain this phenomenon.
Furthermore, animals (e.g. chimpanzeeschimpanzees) and even plants can get cancer, too – so this isn’t a problem that is partial to humans (though that doesn’t preclude new environmental causes).
Apart from that, the quote is complete nonsense:
There is nothing in the natural environment that can cause cancer
Well … no. There are a lot of things in the natural environment that can and do cause cancers. The most glaring point is natural sources of high radiation, such as uranium oreuranium ore and of course the sunthe sun. But more sources exist, such as virusesviruses, infectious diseasesinfectious diseases and dietdiet.