Breastfeeding can help prevent children from asthma or wheezing until they are at least six-years-old, a New Zealand study has found. Researchers gathered information on wheezing and asthma in 1105 children from Christchurch and Wellington at two, three, four, five and six years of age.The protective effect against developing asthma was even stronger in infants and children who have allergies and are therefore more vulnerable.Exclusive breastfeeding for three months within this allergy prone sub-group reduced asthma at six years by 59 per cent, bringing their risk down to that of non-allergenic children.\"These are very robust and convincing results which support a global public health message to breastfeed to prevent asthma,\'\' said lead author Dr Karen Silvers, from the University of Otago.The study showed a lull of the impact of breastfeeding once children hit four-years-old which Dr Silvers said is to be expected as children are exposed to other risk factors for asthma and wheezing grow up. But the fact that exclusive breastfeeding protects well beyond the standard breastfeeding period (the introduction of other food or drink) is remarkable, she said.