Someone asked for links to the Weber University study...I believe this should do http://jmm.sgmjournals.org/cgi/reprint/56/4/519.pdf For a more readable version...Here's one from consumerhealth.org...which is a fairly reliable site: http://www.consumerhealth.org/articles/display.cfm?ID=20050530142700 Clara (who plays a librarian in real life)