Unprocessed cow's milk is known to have a higher omega-3 fatty acids as compared to pasteurized, homogenized, or low-fat milk.
This is one of the apparent reasons why children who consumed this type of milk have a lower probability of developing asthma.
A study by the Ludwig-Maximilians-Universitaet (LMU) in Munich published in the Journal of Allergy and Clinical Immunulogy has revealed that kids who often drink fresh farm milk are less likely to develop asthma, as compared to children who consume the processed type. Further investigation showed that this preventive effect is due to the fact that fresh farm milk has more omega-3 fatty acids as compared to the industrially processed ones. However, the authors of the study still recommend to avoid drinking the untreated type, as it often contains pathogenic microorganisms.
The paper was based on the long-term research project known as PASTURE, which involved around a thousand children who reside in rural areas, in which their mothers were asked to keep records of their child's nutrition and illness until their children turned 6 years old. Analysis of the data gathered from these diaries showed that the number of children who developed asthma by 6 years of age was significantly lower in the group that regularly drank untreated farm milk.
Tabea Brick, a member of the research group that performed the study under Erika von Mutius who is a Professor of Asthma and Allergies at Dr. von Hauner Children's Hospital in Munich, says that the effect that is seen can be partly explained by the higher overall fat content and the higher levels of omega-3 fatty acids found in the untreated farm milk.
Omega-3 Fatty Acids
These omega-3 fatty acids are quite important for human health and have been known to have a number of physiological effects, but they cannot be endogenously produced in the body, and must be acquired only from dietary sources. For example, they are known to serve as precursors for the synthesis of anti-inflammatory substances, says Brick.
The LMU researchers collaborated with another team at Marburg University to assess the composition of the unprocessed farm milk, as well as also analyze that of shop milk that had undergone different types of treatment, such as pasteurization,homogenization, and fat reduction. Upon doing this, it was discovered that the amount of omega-3 fatty acids left in the treated products was inversely proportional to the intensity of processing. In other words, the more processed it is, less omega-3 fatty acids are left in the final product. On the other hand, the level of omega-6 fatty acids, which mainly act as precursors for the synthesis of pro-inflammatory acting compounds in the body, was not changed by any of the treatments.
The standard industrial treatment process for milk usually involves pasteurization of the raw cow milk from a temperature of 72°C to 75°C. The milk then undergoes homogenization to avoid creaming. Mutius and team argue that the development of milder methods for the processing of milk is quite important because this will ensure that a lot of beneficial components found in the raw milk can be retained, but at the same time, pathogenic microbes are effectively eliminated.