I assume Gerwyn is talking about study evidence - of which there is none. If he's talking about anecdotal evidence I'm sure there's evidence on both sides. We have heard from two people that did improve from it and from people who didn't.
True, but as Orla rightly pointed out - at least - there is a problem with anecdotal evidence from people taking or having taken LP.
And talking science, as makes sense, I am with Gerwyn.