No, that part is not true... the reason why the life expectancy was lower is because of the high child mortality rates... you made it past puberty chances where you'd live to 80 easy (ignoring war, abusing your body or epidemics).
/facepalm.
Life expectancy at birth and life expectancy (or life span)... Two different terms. Ultimately, life span in the human population has ALSO increased because of technology. Anyway, that's not relevant to the point, and again (like always) you are missing the point.
Hjelmborg, J.(2006). Human Genetics. 119(3):312-321
Only about 20% of your genetic makeup is responsible for your longevity. The rest is determined by environmental factors and your own behavior. But this again, isn't relevant to the conversation, since we're actually talking about the definition of what New Age douchebags consider natural, and the reality of what nature really is.
Breastfeeding proponents argue that breastfeeding is best because it's the 'natural' option; therefore formula feeding is wrong. This is a half-truth fallacy of believing that formula is bad to begin with. Formula is not bad. The data is inconclusive (and I'd argue a lot of it bunk), as to whether or not breastfeeding will help your kid become a super genius, superman. It's the same line of rationale as the Baby Einstein craze of the late 90's.
The only concrete evidence is that breastmilk contains an ample amount of immnoglobulin A, which helps with the baby's gastronomical immunity. It exists in colostrum, which is expressed for a couple of weeks after birth. Breastmilk possibly has other beneficial antibodies, which formula cannot replicate, but that's really about it.
What happens often in nature is that infants that don't take to breastmilk-or if the mother doesn't produce enough- the infant dies. This is why I can't stand nurses and doctors who try and force the issue. Oh btw, doctors support breastmilk feeding for one main reason, and it ain't because of the research: they're afraid you'll come back and sue their ass if their kid comes back with cerebral palsy. Peds always follow the safest course of action based on social trends because they're a group that has high malpractice issues.
Bottom line is that the breast is best campaign follows the logic that all things natural are warm and fuzzy and good. Nature is not warm and fuzzy. Nature is about the competition and struggle to pass on your genetic material to the next generation.
If I were an evil man, I'd found a start-up company based off of preying on the fears of new parents. Oh wait that's pretty much what every parenting social trend does anyway.
I have a timer going to see when I get a reply that alludes to the notion that I'm against breast feeding, thus proving Fade's idea...