If people took every study ever done on the subject to heart, then breast milk might be that superhuman food.
But a mathematician's analysis of breast-feeding studies found some of them mathematically questionable, and her conclusions have touched off a debate on whether some of the purported health benefits are overblown.
The mathematician, Rebecca Goldin, director of research at STATS, a non-profit group designed to improve the quality of statistical information in the media, said in her review of studies, she really was only convinced of a few health benefits of breast-feeding for full-term healthy babies living in developed world.
"There's a very well-established case to say nursing reduces ear infections, reduces gastrointestinal problems and has a positive immune effect," said Goldin. "But I felt most of the other claims are really controversial."
Even some women who support breast-feeding and have breastfed are wondering about breast-feeding's health benefits.
"I just don't buy it. I'm not convinced it makes a huge amount of difference in the way children turn out nowadays," said Tess Stimson, a writer and journalist.
Although Stimson breastfed all three of her children for the health benefits and to bond with them, she said in retrospect she's not sure it made such a difference compared to neighbors and friends who didn't breast-feed.
"They didn't get any fewer colds than the other children at school, and I don't think they remember it and feel any closer to me because of it," she said.
Even the author of a recent breast-feeding and cardiovascular risk factors study conceded that the health benefits from breast-feeding can be overblown by the time they reach mother's ears, if moms are listening at all.
Last week, an article in Obstetrics and Gynecology found that breast-feeding can later reduce a woman's risk for heart disease and diabetes.
According to the April 21 study, women who lactated for two years during their lifetime had a 13 percent lower risk for high blood pressure and a 20 percent lower risk for high cholesterol than women who never breastfed.
Yet the study couldn't find a significant link between breast-feeding and actually being diagnosed with heart disease.
"Very few women are meeting goals put forward by major medical associations on breast-feeding, so whether it's being overblown or not the message is not getting to women such that they are following through on that," said Dr. Eleanor Schwarz, author of the recent study and assistant professor of medicine, epidemiology and obstetrics, gynecology and reproductive sciences at the University of Pittsburgh.
Indeed, the breast-feeding numbers may be lower than most people think. About 56 percent of mothers are breast-feeding their babies three days after delivery, according to Dr. Miriam Labbok, a physician, professor and director for the Carolina Global breast-feeding Institute.
Although doctors like Scharwz may think reaching bottle feeding mothers eclipses the concern about overblown health claims, not all moms agree.
Some New Moms Feel Pressure, Guilt over breast-feeding
Stimson said she felt stifled by pressure from health care workers even after she decided to breast-feed.
"There was a whole pressure from the midwives who kept weighing the baby and making you feel like you weren't producing enough and [were] a huge failure," said Stimson.
"But the worst thing is that babies don't feed regularly. The more milk they drink, the more you produce," she said. When the baby doesn't want to eat, "that's when your end up with these two huge misshapen bombs on your chest that just hurt to the touch."
However, other women think the evidence is strong enough that women aren't pressured enough.
"I think women should be completely informed of risks and benefits ... everything, so that they can make an informed decision," said Linda Goodman, a mother of five who breastfed her children for the health benefits and convenience.
"But I think for a lot of women there's probably not enough pressure on them," said Goodman. "For example, if someone had their baby taken and their baby is in the NICU, they just give up and stop. But given the help, the chances are that they can still breast-feed."
Experts say there hasn't always been such a debate. In the developing world, the case for breast-feeding is clear cut.
"Prior to antibiotics, we know that babies died if they were not breastfed and that is still true in developing countries," said Dr. Ruth Lawrence, professor of pediatrics at the University of Rochester School of Medicine in New York, and chair of the American Academy of Pediatrics' section on breast-feeding.
"A formula-fed child in a developing country has a 50 percent of dying in the first year of life," Lawrence said. "It's because the water is contaminated."
But take breast-feeding into the developed world with clean water, medicine and top health care, and some of the benefits can start to be disputed. One such debate is cost.
breast-feeding Claims about Cost, Intelligence and Death Controversial
Although Goldin chose to breast-feed all four of her children, as a mathematician some of the health benefit claims cited by American Academy of Pediatrics supporting breast-feeding bothered her.
"They had a little blurb about how it's economically beneficial to nurse," Goldin said. "I nursed all my kids and it was a huge personal cost to me to nurse: You have to work less. You have to sleep an hour more. You have to eat an hour more each day."
"If your time is worth nothing, then, yes, nursing is cheaper than formula," she said. "I'm a mathematician; my time is worth a lot. ... It had been, for me, a huge personal cost -- but for me it was also a huge personal benefit."
Frustrated by the economic benefit claims, Goldin said she started digging into the large pool of literature about the health benefits of nursing.
Goldin found that, at least in 2006, the American Academy of Pediatrics was citing studies that she found mathematically questionable; including studies that breast milk could reduce obesity, increase I.Q., and even reduce the overall risk of death.
"I felt that the quality of that research was not very high," said Goldin. "I'm not trying to say that not nursing couldn't have an adverse effect. I'm asking whether it's proven, and if it's taken at face value, what sort of risk are you're talking about?"
Goldin found one study that concluded breast milk in the developed world could reduce a baby's overall risk of death. But after comparing statistics, she found that risk of death was equivalent to the risk parents take by driving with a child in a car.
"The risk of death that could be attributed to not nursing was equivalent to the risk of regular driving for a year with your child appropriately restrained," said Goldin. "So ... you should throw away the car? You need to walk everywhere?"
breast-feeding Benefit Claim: Not Backing Down
Still, Lawrence asserted that research on breast-feeding -- including research on IQ and immunity -- is largely conclusive.
"Every single baby saves the health care system $450 a year in health care costs is saved by breast-feeding," said Lawrence. "The science is good."
At least Goldin and Lawrence agreed that breast-feeding is a very difficult behavior to study.
"You can't do a blinded placebo control trial: You can't say to one woman, you breast-feed, and another, now you don't," said Lawrence. "It's not like having a cage full of mice."