Awesome post! And yeah, that’s how it works. Two or three nutritionists with celebrity status (maybe working with the LA Lakers, maybe have a popular radio or TV show…) make some claim, and a lot of people buy it without checking.
The fact is, Mediterranean people have been eating diets high in nuts and seeds for centuries, and they live longer and healthier lives than Americans, who don’t. That doesn’t mean the nut and seed oils are making them live longer, but it does mean they aren’t so unhealthy that they are living shorter lifespans.
It’s also worth noting: Soylent has been pretty popular since it originally came out in 2013. I don’t know if anyone has managed a 100% Soylent diet in the 7 years since, but plenty of people have used Soylent as a significant part of their diet and some have used it as a majority of their diet. Now, the recipe has changed a few times since, but if there was anything in Soylent that would cause significant health problems within a 4 to 7 year timespan (depending on how long that ingredient was in it), we would have seen enough reports of people having issues to be aware of the problem. If I am not mistaken, soy oil has been a prominent ingredient in Soylent from the beginning. If high consumption of soy oil caused any significant problems, Soylent would almost certainly have provided significant evidence of that. As it is, the biggest issues caused by Soylent seem to have been gastrointestinal distress, which is annoying but not generally serious, and which they have managed to fix fairly quickly any time it arose.
This doesn’t mean there aren’t ingredients that might cause problems after more extended use, but any claims about prominent ingredients in Soylent causing significant issues only within a period of a few years have pretty much been disproved by the fact that such issues have not been reported by any significant number of people using Soylent.