I tell them that there is no doubt that babies who are breastfed are more
intelligent.  There are theoretical reasons for this (absence of long
chained polyunsaturated fatty acids in artificial baby milks, lower levels
of toxic metals such as lead and aluminum, lower levels of certain amino
acids like tyrosine, and other reasons).  The clinical studies, in general,
support the thesis.

So a negative study or two, in a very complex issue, admittedly, does not
undo all the positive studies.  One study in Great Britain looked at over
13000 babies, and found definite benefit, even allowing for socio economic
conditions.

Go to websites below for Risks of Artificial Feeding, and you will find more
studies on this issue.

Jack Newman, MD, FRCPC

http://www.erols.com/cindyrn/drjack0.htm

or

http://www.bflrc.com/jn_arts.htm