@vic @Tadano @scalar @JedKron1248 >we don’t know how far back and to what extent the lying has occurred, namely: can I trust a medical study from the 1990s? 1950s? 1800s?

Regular scientific studies from the pre atomic age are good. As least for foundational knowledge, it's an excellent place to start. Things like chemistry don't stop applying when you're in a human body, but you have to learn stuff like normal ranges, compartmentalizing and cascading reactions to really get practical application of stuff. It does function like a system and there's a lot of specialist components that often have multiple uses.