Dr.Martinez said:

International shipping tracking for cross-border ordering orders: my experience with customs in the US when ordering from overseas: Required FDA…

Thank you for spelling out the reasoning rather than just the conclusion.

Adding the clinical framing, because it changes how the question reads. 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.

ingrid_STO said:

The useful move here is to separate what is established from what is widely repeated.

I read this differently. The confidence in this thread is running ahead of the evidence, and I would rather the uncertainty were stated than smoothed over because it is unsatisfying.

Adding the numbers, since they settle part of this. 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.

Moderator note: two posts asking for a source have been merged into one. Please search the thread before asking again.