Infants fed on fresh cow's milk rather than processed milk are less prone to infections, a pan-European study has found.
Researchers recommend the use of alternative processing methods to preserve the protectants found in the natural milk.
The study, led by Professor Erika von Mutius, Professor of Pediatric Allergology at Ludwig-Maximilians-Universitat Munchen (LMU) in Germany, found that fresh cow's milk protects young children from respiratory infections, febrile illness and inflammation of the middle ear.
As untreated cow's milk may itself contain pathogenic microorganisms and could pose a health risk, the researchers argue for the use of processing methods that preserve the protective agents present in raw milk.
The study initially recruited 1,000 pregnant women who were asked to document their children's diet and state of health at weekly intervals during the first year of life.
"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-pasteurised product," said Georg Loss, first author of the paper.
Ingestion of farm milk reduced the risk of developing these conditions by up to 30 per cent, and the effect was diminished if the milk was heated at home before consumption.
Conventionally pasteurised milk retained the ability to reduce the risk of febrile illness, while exposure to the higher temperatures used in Ultra-high temperature processing (UHT) eliminated the effect altogether.
Importantly, the positive impact of raw milk could be clearly separated from the confounding effects of other elements of the children's nutrition, researchers said.
"The effects of diverse milk treatments are presumably attributable to differentially heat-resistant components present in fresh milk. Compounds that are sensitive to heating seem to play a particularly important role in protection against respiratory-tract and ear infections," said Loss.
At the end of the first year of life, blood samples were obtained from the children enrolled in the study, and tested for biochemical indicators of immunological function.
Infants fed on unprocessed milk were found to have lower levels of the C-reactive protein, which is a measure of inflammation status.
"Other studies have shown that higher levels of inflammation are related to the subsequent emergence of chronic conditions such as asthma and obesity. Consumption of unprocessed milk may therefore reduce the risk of developing asthma," Loss said.
The study was published in the Journal of Allergy and Clinical Immunology.
