One reason why children today seem to catch infections more easily may well be the increasing scarcity of fresh cow's milk, researchers have found.
Infants fed on fresh rather than ultra-high temperature (UHT) processed cow's milk are less prone to respiratory infections, febrile illness and inflammation of the middle ear, the findings showed.
Ingestion of farm milk reduced the risk of developing these conditions by up to 30 percent, and the effect was diminished if the milk was heated at home before consumption.
"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 first author Georg Loss from Dr. Von Hauner Children's Hospital in Munich, Germany.
The study 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.
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.
As untreated cow's milk may itself contain pathogenic microorganisms and could pose a health risk, the researchers argued for the use of processing methods that preserve the protective agents present in raw milk.
The study appeared in the Journal of Allergy and Clinical Immunology.