I have a reference that I can't put my hands on this second, but was the  basis for information in a session at a conference in the 90's.  It says that because growth factors (?) and other components of breastmilk did indeed make the gut more porous, this researcher recommended NOT mixing breastmilk and formula, in fact, not giving one within about 3 hours of the other.  The reason was that the breastmilk would increase the chance that foreign proteins from the formula could cross the gut and stimulate the immune system to initiate an allergic response.  He felt that a combination of formula/breastmilk was the most likely scenerio for the developement of allergies, much more so than the exclusive feeding of either breastmilk or formula.  Once the baby was 3-4 months old and the gut had matured and "closed" then the risk would be much less.  So he strongly recommended exclusive breastfeeding for as long as possible.

I will try to locate the paper.  Perhaps someone else remembers this.

Warmly,
Sharon Knorr, BSMT, ASCP, IBCLC
Newark, NY (near Rochester on Lake Ontario)
mailto:[log in to unmask]

             ***********************************************

To temporarily stop your subscription: set lactnet nomail
To start it again: set lactnet mail (or digest)
To unsubscribe: unsubscribe lactnet
All commands go to [log in to unmask]

The LACTNET mailing list is powered by L-Soft's renowned
LISTSERV(R) list management software together with L-Soft's LSMTP(R)
mailer for lightning fast mail delivery. For more information, go to:
http://www.lsoft.com/LISTSERV-powered.html