From the other side of the consultation, briefly. There is a difference between no evidence and evidence of no effect, and this subject is one where the two get swapped freely in both directions.

That is the short version; the long version is somebody else's post.

Found this through search years later and it is still the best discussion of the question, so adding one thing. Keep the original post as written when you update it, and add the correction underneath. An edited-away mistake is invisible to the next person who makes it.

PedsEndoPhilly said:

There is a difference between no evidence and evidence of no effect, and this subject is one where the two get swapped freely in both directions.

Adding the part of the answer the thread has not reached. It is worth asking what the claim would look like if it were false. If nothing would look different, it is not a claim about the world and no amount of discussion will settle it.

One concrete data point for the thread. For anyone reading later: the numbers in this thread are worth checking against a primary source before you act on them, including mine. Half the figures circulating in this community trace back to a secondary summary that dropped a qualifier.

Following on from PedsEndoPhilly — and this may be the naive question:

How would you tell the difference between that and the alternative explanation?