I would love to blame highly processed foods for a recent spike but those are not new. They are surely a factor and have been since at least the 1970's but there are newer factors that nobody will appreciate me linking. [1][2]

[1] - https://www.youtube.com/watch?v=ayfRq-CPF6I [video][18 mins]

[2] - https://biomarkerres.biomedcentral.com/articles/10.1186/s403...

The bro science I've heard around this is that emulsifiers and fake sugars aren't easily digested, and therefore sit around in the GI tract as fuel for pathogens.

My mind was kinda blown recently when I couldn't find a single ice cream brand that didn't have some form of nasty thickener. It's insidious.

This is the study that the Guardian article talking about https://www.bmj.com/content/378/bmj-2021-068921

So, before everyone accuses their favorite mechanism:

"After multivariable adjustments, men who consumed ultra-processed foods in the highest fifth had a 29% higher risk of developing colorectal cancer than did those in the lowest fifth...However, we found no significant association among women"

and

"our results show that the association between ultra-processed food consumption and colorectal cancer among men was largely independent of body mass index."

and finally:

"Why the association was seen in men but not in women is unclear."

They also saw the obvious factors (smoking, alcohol, being sedentary, etc.) correlate with cancer, but were accounted for.

So this is a sex-based result. Make of that what you will.