by Heidi Green
November 17, 2008

Breastfeeding is well-recognized as having many benefits for the health of infants and children. Several studies have reported that breastfeeding has a protective effect on lower respiratory infections (Cushing 1998; Nafstad 1996; Oddy 2001; Oddy 2003; Sinha 2003; Hoddinott 2008), but the effect on asthma risk has been unclear. Now, a new study may shed some light on how breastfeeding positively affects lung function, even a decade later.

Led by Dr. Ikechukwu Ogbuanu, the team looked at data collected from more than a thousand 10-year-olds who were members of the Isle of Wight (UK) birth cohort. Because data on breastfeeding practices and duration were available for these children, the research team was able to collect lung function data from them and analyze it to assess the impact of their early feeding methods.

Research
Dr. Ogbuanu and his team looked at breastfeeding practices and duration as they had been assessed at birth and at one-year and two-year follow-up visits. They categorized the children as: not breastfed, breastfed less than two months, 2–4 months, or longer than four months. They also considered maternal history of allergy or asthma and measured the children’s lung function at 10 years of age.

Results
Dr. Ogbuanu and his colleagues discovered that the lung function of those who were breastfed for at least four months was much better than that of children who were not breastfed.

Their findings are thought provoking. We have known that breastfeeding provides benefits in addition to simply conveying nutrition. (Think about the immunological protection provided to breastfed youth, or the pain relief experienced by breastfed infants during clinical procedures.) Now, we come to think that the “work” of suckling may prove to be a sort of necessary, health-enhancing respiratory exercise.

Recommendations
This is just one study. It relied on maternal report of asthma and allergy, as well as recall of breastfeeding duration. Plus, the study is limited in that it does not include breastfeeding durations beyond four months, even though six months of exclusive breastfeeding is recommended by such leading authorities as the World Health Organization and the American Academy of Pediatrics. Still, here’s what I think:

• Parents: Breastfeed, at least four months. Less than four months doesn’t seem to confer benefits to lung function. We don’t know the effects of more than four months. If you can breastfeed, make this your minimum goal.

• Manufacturers: Improve your bottles. While it may seem to be beneficial for babies to have an easy time drawing formula or expressed milk from their bottles, this study suggests that is not the case and that the “work” of suckling is a form of exercise. Bottle manufacturers, please help us make sure our babies do their suckling “reps” at each feeding. (Readers may be interested to note that, according to study co-author Dr. Syed Arshad, the research team is already working with a bottle manufacturer to try to develop a better bottle.)

• Everyone: Keep an eye out for future studies. Dr. Arshad notes that it is now possible to test lung function in infants and that such a study could be conducted within a year. We can expect to see results within the next few years. Even aside from lung function, this study reminds us that the full benefits of breastfeeding are still being discovered. This is an area of emerging science, and there are likely even more benefits to the breastfed infant that we don’t know. Yet.