An infant has to work for nourishment at its mother’s breast, and the exercise helps build healthier lungs, according to research led by University of South Carolina (USC) Arnold School of Public Health scientists. Dr. Ikechukwu U. Ogbuanu and Dr. Wilfried Karmaus reported that children who were breastfed for at least four months have a significantly larger lung capacity at age 10 years compared with a similar group that had not been breastfed.

The study involved a group of 1,033 children on the Isle of Wight, an island off the south coast of England. Dr. Karmaus has conducted respiratory and allergy research on the cohort for several years.

The results of the study are reported in the November 10, 2008 online-first issue of Thorax, an international journal of respiratory medicine.

Drs. Ogbuanu and Karmaus are researchers in the Arnold School’s department of epidemiology and biostatistics. Both have medical degrees and Dr. Ogbuanu is a doctoral candidate in epidemiology.

The researchers found that the lung volume of ten-year-olds who nursed for at least four months was 54 milliliters greater than in those who had not been breastfed at all.

Breastfed infants get about an hour of exercise daily for the first four months, with six to eight feedings lasting about eight minutes each. That is nearly twice the length of individual bottle feedings, which average about 4.4 minutes and require less efforts.

The USC scientists found that children who had been breastfed for less than four months had improved lung capacity but it wasn't significantly different from the lung function of children who weren't breastfed at all.

Dr. Karmaus said that based on the study, researchers are in the process of developing a feeding bottle that will mimic the exercise involved in suckling at the breast. The bottle may be useful in women who are not able to directly breastfeed.

Dr. Karmaus said that many infants in the United States miss the benefits of breastfeeding because so many women pump milk from their breasts and then feed using a bottle. He suggested that the absence of adequate maternal leave probably encourages the practice. Dr. Karmaus noted that in Canada and Europe maternity leave policies make it possible for women to directly breastfeed their infants for several months.