Those observations are contained in National Health Service literature which is wrong or out of date, said Dr. Michael Kramer, who has advised UNICEF and the World Health Organization.
There is evidence, however, that mothers who breastfeed are more likely to lead a healthy lifestyle and follow expert advice on health issues, Kramer said.
NHS leaflets for pregnant women and new mothers said that breastfeeding protects a baby against obesity, allergies, asthma and diabetes. Those claims are repeated by most other public health groups in Britain, such as the Royal College of Midwives and the National Childbirth Trust, The Times of London reported Monday.
Jacque Gerrard, a spokeswoman for the Royal College of Midwives, defended the advice in the leaflets.
"Breastfeeding is the right way to produce healthy babies," Gerrard said.