Researchers from Ludwig-Maximilians-Universitaet (LMU) in Munich, Germany, investigated what several epidemiological studies had already suggested – that children who drink fresh, unprocessed, farm milk on a regular basis are less prone to develop asthma than those who drink industrially processed milk.
However, the researchers warn against consuming raw milk because it may contain harmful pathogens.
The study, titled “ω-3 fatty acids contribute to the asthma-protective effect of unprocessed cow’s milk,” published in the Journal of Allergy and Clinical Immunology, found that fresh, unprocessed milk has a higher content of omega-3 fatty acids than pasteurized, homogenized, or low-fat milk. This is an important factor that might explain why children who consume unprocessed milk are less likely to develop asthma and other allergies.
The comprehensive research project, named PASTURE, funded by the European Commission, followed more than 1,000 children who live in rural areas and whose parents kept a record of their nutrition habits and illnesses up to the age of 6. The project was led by Erika von Mutius, a pediatric allergology professor from LMU and head of the Department of Asthma and Allergies at the Dr. Von Hauner Children’s Hospital in Germany.
The assessment of the children’s health diaries revealed that the amount of children who had been diagnosed with asthma by the age of 6 was considerably lower among those who regularly consumed untreated farm milk. “The effect can be partly explained by the higher overall fat content and the higher levels of omega-3 fatty acids found in farm milk,” Tabea Brick, part of the research team, said in a news release.
Together with another research group at Marburg University, the LMU investigators evaluated the composition of raw farm milk in comparison to industrial milk that had been heavily processed — either through fat reduction, homogenization or pasteurization — and the results showed that the level of omega-3 fatty acids left in the end product was inversely proportional to the amount of processing.
On the other hand, the number of omega-6 fatty acids – which act as precursors for pro-inflammatory molecules – did not show signs of change throughout any of the processing methods used.
According to the study, this effect is specific and clearly distinguished from the possible impact of other factors. While omega-3 fatty acids are essential for human health, they cannot be synthesized in the human body and have to come from external dietary sources. The fatty acids are thought to have several positive physiological consequences. “For example, they are known to serve as precursors for the synthesis of anti-inflammatory substances,” Brick said.
The study’s authors concluded that the manufacture of less processed milk could ensure the retention of beneficial components present in the raw milk version — if it could also guarantee that potentially dangerous pathogens were eliminated. The authors do not recommend the consumption of raw milk precisely because it may contain harmful pathogenic microorganisms.