So people kind of knew asbestos was harmful wayyy before it mostly stopped being used in 1979 (USA). But, it was still used constantly in many industries and ended up everywhere. What do you think is an example of something we find out is DRASTICALLY harmful 10-50 years from now? My guess would be screen time.
You’re totally on the money with your core thesis about epidemiological studies here, and I agree processed meats as a standalone variable are likely a massively overplayed factor in CRC research.
When it comes to the more general claims in the GP comment though, re: processed food and low fiber, there are literally hundreds of independent studies at different levels all pointing in similar directions. It’s pretty incontrovertible at this point.
See any recent review on CRC etiology for reference, e.g.: https://www.researchgate.net/profile/Elroy-Weledji/publication/377724506_Clinics_in_Oncology_The_Etiology_and_Pathogenesis_of_Colorectal_Cancer_OPEN_ACCESS/links/65b3f83e79007454973be66e/Clinics-in-Oncology-The-Etiology-and-Pathogenesis-of-Colorectal-Cancer-OPEN-ACCESS.pdf
Thanks for an interesting source!