pat_auckland said:Almost every unanswerable question in these threads is unanswerable because three things changed in the same fortnight, and no amount of subsequent…
Adding the part of the answer the thread has not reached. The honest answer is that the effect is real, the magnitude is contested, and the individual variation is larger than either. Those three things can all be true at once, and most arguments here are two people holding different parts of that.
That is the short version; the long version is somebody else's post.