For the video of Dr. Myers, try this link:
http://askdrmyers.wo...rostate-cancer/
Thanks for this. The first study to which he alludes (actually what he describes could refer to either CARET or ATBC or both ) we've gone over before and I don't think are good reasons to exclude it: the studies in question were at much higher dose than we're using (20 mg beta-carotene (ATBC) or 30 mg beta-carotene + 25 K IU retinol (CARET)), used synthetic (all-trans) beta-carotene, gave it in isolation from coantioxidants (C and E and maybe Se), and was in smokers (which depletes key coantioxidants). The second study was in high-dose multivitamin use, and didn't specifically implicate beta-carotene. I'm not sure what the third study is to which he refers; in fact, looking around for a study by Seattle researchers on blood levels of beta-carotene in prostate cancer patients led me to this, which if anything found the reverse.
So I don't see this as a good argument against its inclusion at the dose and in the form we've included.
