Professor Michael Kramer, from Montreal's McGill University, has claimed that much of the evidence we hear about how good it is to breastfeed our babies is either wrong or out of date.
Kramer, who has spent more than 20 years studying the subject, believes that a significant amount of evidence behind the claims is flawed.
Kramer's work has failed to show breastfeeding provides protection against diseases.
He has claimed that many of the supposed advantages can be explained by differences in lifestyle.
"I don't favour overselling the evidence - we should not be conveying false information," Perth Now quoted him as saying.
However, studies showing breast milk wards off ear infections and stomach bugs stand up to scrutiny.
Kramer also believes it may be good for the developing brain, leading to a slight increase in IQ.
He said the confusion was exacerbated by competition between the formula milk industry and the breastfeeding lobby.
"The formula milk industry jumps on every piece of equivocal evidence. But the breastfeeding lobby have a way of ignoring the evidence. Both sides are not being very scientific," he said.
Australian Breastfeeding Association counsellor Lindsay Giannakos said: "I have found breastfeeding does not protect my children from all illnesses, but I do believe had I chosen to not breastfeed they would have been at increased risk of many health issues such as allergies . . . obesity and diabetes. In my opinion, breastfeeding is the normal way to feed a child and factories cannot manufacture an equal substitute."