Bonnie,

Please take a moment to read these two articles just published in The Lancet (A highly regarded UK medical journal):

http://www.thelancet.com/journal/vol361/iss9365/full/llan.361.9365.original_research.25217.1

and commentary about it:

http://www.thelancet.com/journal/vol361/iss9365/full/llan.361.9365.editorial_and_review.25275.1

You need to register to get them, but it is FREE.

Betsy