Published Online: October 21, 2014
Respiratory tract infections are a common problem in early life. In addition to their individual and economic burden, they may play a key role in the development of asthma during childhood. Breast-feeding is known to protect against said infections. Given the similar composition of human milk and cow’s milk, Loss et al. investigated whether cow’s milk also protects from respiratory infections in the first year of life. Their results were recently published in The Journal of Allergy and Clinical Immunology (JACI).
The authors of this study recruited 1000 pregnant women from rural areas in Germany, Finland, France, Switzerland, and Austria. Mothers documented their children’s diet and milk consumption, and state of health including occurrence of respiratory infections at weekly intervals during the first 12 months of life. At the end of the first year, blood samples were obtained from the children, and tested for C-reactive protein (CRP) levels, a biochemical indicator of inflammation status.
Among children who were fed on fresh unprocessed cow’s milk the incidence of head colds and other respiratory infections, febrile and middle-ear inflammation was found to be significantly lower than in the group whose milk ration consisted of the commercially processed ultra-heat treated product (UHT). Ingestion of fresh milk reduced the risk of developing these conditions by 30%, and the effect was diminished if this milk was heated at home before consumption. Conventionally pasteurized commercial milk retained the ability to reduce the risk of febrile illness as compared to UHT milk, which is processed at much higher temperatures. Importantly, the positive impact of unprocessed fresh milk could be clearly separated from interfering effects by other elements of the children’s nutrition. In addition, infants fed on unprocessed milk were found to have lower overall inflammation status at the age of 1 year as indicated by lower levels of CRP.
This study provides first evidence that components of fresh cow’s milk, not present in heated or otherwise processed milk, protect against respiratory infections and middle-ear inflammation in early life. However, untreated cow’s milk may contain harmful bacteria that cause serious illnesses and its consumption should not be recommended. A novel microbiologically safe yet minimally processed milk might be of major public health relevance for common respiratory infections and possibly for subsequent development of severe airway diseases such as asthma. A prevention strategy based on a safe and well-accepted food of everyday nutrition might succeed without profound changes in life-style.
The Journal of Allergy and Clinical Immunology (JACI) is an official scientific journal of the AAAAI, and is the most-cited journal in the field of allergy and clinical immunology.