Watch Dr. Barnard on this short video -- excerpts from a show he did on PBS:
[ame]http://www.youtube.com/watch?v=Pcs6MSdG2W0[/ame]
If you are really interested, watch the next three videos which go into more detail:
[ame]http://www.youtube.com/watch?v=8kJRX9-cb6o[/ame]
[ame]http://www.youtube.com/watch?v=Q1H5vjxmt6Y&NR=1[/ame]
[ame]http://www.youtube.com/watch?v=lRY7YiSuchA&NR=1[/ame]
