Several people cited the AHS-2 as a pseudo-RCT that supported veganism. There’s one commenter on LessWrong and two on EAForum
The LessWrong link here links to my comment even though I did not describe the AHS-2 as a “pseudo-RCT.” So I think your description of that comment is misleading.
Edit: it’s also misleading to say that “Outcomes for veganism are ~tied with pescetarianism in men, and are worse than everything except for omnivorism in women” in AHS-2, as I explained on LW.
As I explained elsewhere a few days ago (after this post was published), this is a very misleading way to describe that study. The correct takeaway is that they could not find any meaningful difference between each diet’s association with mortality among women, not that “[o]utcomes for veganism are [...] worse than everything except for omnivorism in women.”
It’s very important to consider the confidence intervals in addition to the point estimates when interpreting this study (or any study, really, when confidence intervals are available). They provide valuable context to the data.