I agree that it's really complex and not straightforward, especially since there are so many unknowns, confounding factors, and since so much is different from

I agree that it's really complex and not straightforward, especially since there are so many unknowns, confounding factors, and since so much is different from person to person (microbiota, genetic and especially epigenetic factors, the effects of hormesis, etc) but at the same time, just because it's complex doesn't mean that science (or individuals) should throw their hands up and say "well, there are no conclusions that can be made about human diet" as that seems to be patently untrue. Also, just because people can't read hundreds of studies doesn't mean that they aren't out there, or that haven't been done (tens of thousands of studies, of all kinds, which taken together do point to much more specific things than "eat some nuts"), or that it's excusable when medical professionals make recommendations that are contradicted by the preponderence of scientific evidence.