An interesting study has confirmed that breastfeeding has benefits for childhood asthma.
The study of 1,100 babies showed that exclusive breastfeeding for at least 3 months or longer in children with eczema or asthma was associated with significantly reduced asthma symptoms. The study showed this effect persisted in children at 4, 5, and 6 years of age. Each additional month of exclusive breastfeeding had a beneficial effect in reduction of the rate of asthma in these children.
Although many breastfeeding mothers are concerned that their babies with allergy symptoms may be sensitive to something in their milk, resorting to formula feeding is likely to do more harm than good. Breastfeeding has so many beneficial effects on immune function that exclusive breastfeeding for 6 months just makes good sense. If mothers are concerned about persistent symptoms in their babies, then taking a holistic approach to asthma in addition to continued breastfeeding will help alleviate wheezing and build a strong immune system.
See also this article on asthma in children.
Oddy, WH. Longer duration of exclusive breastfeeding associated with reduced risk of childhood asthma up to age six. Evidence Based Nursing. 2013;16(1):18-19.