On top of the very valid points everyone else has made I also have to question whether, even if we believe that breastfeeding might give you x points, and good nutrition x points, etc whether those points come from correlation not causation and are in fact roughly speaking the SAME few points. No-one has researched all those things together or in their various combinations, each has been (possibly rather dubiously) looked at in isolation. You can't then go well "study" #1 + "study"#2 + "study" #3 = 15 points!
I would think that for the most part the extended breastfeeders are also more likely to be careful with other nutritional needs, also more likely to provide a rich environment, etc. You could include someone who does all three into three different studies for just one of those behaviours and pick up their "extra" 5 points in all three studies(which may well be genetic). You can't then say that their child would have been 15 points worse off if they had not done any one of those three things.
they did do the study, and found there was a gene involved with the susceptibility to harm from formula. That gene had better not be related to susceptibility to IGT or PCOS, is all I can say.
http://www.physorg.com/news113505546.html
