While it has been recognised for decades that breastfeeding is better for both mothers and babies, scientists are now suggesting that it also benefits a child's intelligence.
In one of the most comprehensive studies conducted to date on breast feeding, the researchers say breastfed babies are more intelligent.
In a study involving 14,000 children living in Belarus who were monitored from birth to over six years, it was found that breastfed babies were more intelligent than those weaned on formula milk.
The findings which were based on IQ and academic ratings at age six, show that those who were breastfed performed significantly better in IQ tests.
The researchers found that by age six and a half, children who had been exclusively breastfed scored 7.5 points higher in verbal intelligence tests and 5.9 points higher in overall IQ tests - this was supported by their teachers who found that the breastfed children rated higher at reading, writing and solving mathematical problems.
Earlier research had reached the same conclusion but it raises the issue as to whether it is breast milk itself or the associated maternal care that is responsible for boosting the intelligence of developing babies and such an effect will be difficult to prove.
The problem lies with the fact that almost every study carried out to date has involved mothers deciding beforehand whether or not they plan to breastfeed and this then raises the possibility that breastfeeding women were simply brighter, or were likely to interact more with their children.
This latest study by researchers at McGill University in Montreal looked at children born at 31 maternity hospitals and clinics across Belarus between 1996 and 1997.