> Saying it's natural suggests that we have atleast evolved with it in the environment, likely interacted with it at times and have developed biological means of interacting and dealing with it.

The post you replied to has already refuted your argument. We evolved with poisonous mushrooms in our environment and our body's "means of dealing with it" are to die. That's hardly the gold standard for biological responses, don't you think?

Well that's definitely not true. Many of the most potent toxins known to us are produced by living organisms – for an example, actually read the comment you replied to. You can find examples of substances that are spectacularly lethal to us from all of the five major kingdoms of life. Merely saying something is natural does not imply we co-evolved with it at all, and even if we had, it doesn't automatically follow that selection always gives us the means to "deal with it" in the way you suppose.

I get your point, but as the above poster said, often the body's way of dealing with things is to suffer and/or die. So...how is having an existing way to "deal with it" terribly helpful?

(Not trolling, seeking honest clarification)

Yeah. I think the "natural" people aren't saying all natural things are better than all man-made things. e.g. Poison ivy tea isn't better for you than Pepsi.

But, looking at what generations of long-lived people tend to eat[1] is probably a reasonable guide to nutrition and health. Manufactured/artificial stuff simply isn't on that list since that stuff hasn't been around long enough to be part of a multi-generational study.

[1] https://www.ted.com/talks/dan_buettner_how_to_live_to_be_100...

Actually, zero calorie stuff is pretty much by definition stuff we haven't decided to "deal with". It doesn't get absorbed directly, and we never created a means to break it down into something that could be absorbed. The goal for a non-caloric sweetener is to be noticed by receptors on the tongue by chance while the rest of your body explicitly ignores it. Biological response is the "problem".

You can make the same argument for poisonous mushrooms, but I wouldn't recommend consuming them.