Kellymom and Jack Newman have some great info about the risks of formula.
http://www.kellymom.com/nutrition/mi...t-formula.html
Here is a list of studies (but no abstracts)
http://www.kellymom.com/newman/risks...ula_08-02.html
and from the BF task force of LA:
http://www.breastfeedingtaskforla.org/ABMRisks.htm
I don't like to think of formula as 'bad'. Formula fed babies are at higher risks for illnesses and health problems (NEC, respiratory infections, GI infections etc etc.) For most babies, formula adds many more risks than benefits. Moms need to know of these risks. Without formula,
some babies would be very ill. Because we don't have enough milk banks, some infants must have formula (for example if the mother doesn't have enough milk, if she is on chemo, etc.). And there are some infants with bad sensitivities or allergies who need elemental formula. Just like medications are needed for some babies, and the benefits of those medications outweigh the risks for that particular baby, some babies need formula, and the benefits outweigh the risks for that baby.