Background and methodology:
Milk fat has historically been regarded as unhealthy because of its relatively high level of saturated fat. However, recent research has found a reduced risk of cancer and cardiovascular disease associated with some of the mono- and poly- unsaturated fatty acids found in milk. This includes α-linolenic acid (α-LA; the main omega-3 fatty acid found in milk), conjugated linoleic acid (CLA) and vaccenic acid (VA).
Milk also has been recognized as a source of certain fat-soluble antioxidants such as vitamin E and carotenoids. Higher intake of antioxidants is thought to protect against oxidative cell damage and reduced the risk of certain chronic diseases.
This study compared fatty acid profiles and levels of fat-soluble antioxidants in milk from organic and conventional production systems in five geographic regions in Europe (Wales, England, Denmark, Sweden and Italy). Milk samples were collected from the bulk tanks of 50 commercial farms on four or five dates between June 2004 and May 2005.
Results indicated that levels of nutritionally desirable mono- and poly-unsaturated fatty acids (vaccenic acid, CLA, α-linolenic acid) and/or a range of fat soluble antioxidants were found to be significantly higher in organic milk than in conventional milk. The higher levels of fat-soluble antioxidants in milk from organic production would be expected to increase the oxidative stability of milk.
Butler, G., Stergiadis, S., Eyre, M., Leifert, C., Borsari, A., Canever, A., Slots, T., & Nielsen, H. J. (2007). Effect of production system and geographic location on milk quality parameters. Paper presented at 3rd QLIF Congress: Improving Sustainability in Organic and Low Input Food Production Systems, University of Hohenheim, Germany, March 20-23, 2007. Available on-line at: http://orgprints.org/10625/