Several users kept pointing out aspartame metabolizes into formaldehyde and that aspartame wasn't approved for 16 years by the FDA until Donald Rumsfeld, former president of the company that manufactures it (Searle) gave the FDA commissioner the boot and appointed a new one.
The wikidorks (aspartame shills?) who police the aspartame article and prevent people from editing it could only respond by ignoring the entire conflict of interest and insisting over and over that the users pointing this out were "paranoid" and "conspiracy theorists" and falling back on industry-funded studies (literally the private corporation that made it studying it) saying it's safe, and the FDA being ultimately trustworthy. They accused the users of "writing a blog" and "diffusing history" (????) and said that this isn't what the talk page is for.
They said that the talk page is only for "suggesting ways to improve the article (that they police)" (????????) When that didn't work they finally accused their interlocutors of being traditional sugar shills, at which point someone responded that both sugar and aspartame are bad for you, and that the USA allows high fructose corn syrup while other countries don't, because it has lax regulations. This is when the entire conversation was shut the fuck down.
TL;DR wiki nerds get to invoke "it's not a forum" rule to shut down people "diffusing history" while accusing their interlocutors of being "paranoid conspiracy theorists" and claiming that pointing out conflicts of interest in the FDA approval is wrong because... the FDA is the most reliable source.
https://en.wikipedia.org/wiki/Talk:Aspartame
It isn't that surprising that formaldehyde is created as a waste product by the liver, it's a pretty simple molecule; but it would almost always be formed by transforming something else that was more toxic in the original form prior to processing it down to formaldehyde.
Context is pretty important, where it is, the life cycle of that molecule, the acidity of that environment could all change it to be completely harmless vs. almost certainly carcinogenic. Alcohol absorption in the GI tract is a horrific carcinogen, it's no benzene but it's still massively destructive. But nobody really seems to be concerned about it other than cancer researchers, who don't even have enough pull to prevent the wine lobby from pretending wine is good for you other than one of the biggest known influences in developing breast cancer.