Writing in the Journal of Dairy Science, scientists at Cornell University set out to compare the nutritional profile of organic and recombinant bST (rbST)-free milks in the US with that of conventional milks.
They pursued this research because of concern that consumers may be misinterpreting organic and rbST-free labelled milks – which are an increasingly common sight in grocery stores.
“Consumers have little knowledge of the how milk is produced, and the information search for most Americans rarely extends beyond package labelling and retail marketing," stated the scientists.
“Of particular concern is that some consumers may perceive that this type of specialty labelling indicates differences in the quality, nutritional value, or safety of dairy foods.”
To investigate the nutritional values of the different milk types, the researchers looked at a sample of 292 milks, and narrowed their investigation to an assessment of their fatty acid composition.
They only found statistically significant differences between the fatty acid profile of organic and conventional milk, but none of these were judged meaningful. The milks were all considered “similar in nutritional quality and wholesomeness.”
In addition, the differences were ambiguous. “From a public health perspective the direction for some of these differences would be considered desirable and for others would be considered undesirable.”
To improve the nutritional profile of a milk drink, the scientists concluded that dietary components and formulation are much more relevant than production management practices. For example, the scientists cited research indicating that feeding cows supplements of fish oil or other products rich in EPA and DHA can improve the fatty acid profile of milk.
Support for the study was provided by Cornell Agricultural Experiment Station, the Monsanto Company and the Cooperative State Research, Education, and Extension Service, USDA.
Source: Journal of Dairy Science
Survey of the fatty acid composition of retail milk differing in label claims based on production management practices
Authors: M. O’Donnell, K.P. Spatny, J.L. Vicini and D.E. Bauman