Breastfeeding helps protect a child from developing asthma for up to six years, a study has found.
The Otago University study says the results were strong for exclusive breastfeeding, but any breastfeeding has protective effects.
These effects were even greater for children who suffered from allergies that made them more vulnerable to developing asthma.
Exclusive breastfeeding for three months for allergy sufferers brought the children's risk of developing asthma down 59 per cent, to the same level as children who did not have allergies, the study found.
The study looked at 1005 babies in Christchurch and Wellington over six years.
Lead author Dr Karen Silvers said if every infant in the group had been exclusively breastfed for the six months recommended by the World Health Organisation, current asthma rates would have been reduced by half at two years and 30 to 40 per cent up to age six.
The impact of breastfeeding started to wane when the children were four, which was expected as children were exposed to other asthma risk factors as they got older, Dr Silvers said.
It was remarkable breastfeeding protected a child for so long after they started consuming other foods and drinks, she said.
"These are very robust and convincing results which support a global public health message to breastfeed to prevent asthma."
NZN