According to an important new study, organic milk sold in England delivers significantly higher levels of healthy fatty acids than does conventional milk. The study, funded by the European Union and published in the peer-reviewed Journal of Dairy Science, can be accessed for free
here.
The researchers compared fat composition and protein content of 10 organic and 12 conventional brands found on supermarket shelves in northeast England. Researchers found that the organic milk had only slightly higher overall fat content, but much higher levels of what it calls "beneficial fatty acids."
The differences are significant in public-health terms. In America and Great Britain alike, people on average don't get enough essential fatty acids. For example, one of the fatty acids in question, conjugated linoleic acid (CLA), has been shown to lower heart disease and cancer risks, the researchers say. The meat and milk of ruminant animals are "almost our exclusive source of dietary CLA," the researchers support -- and organic milk has significantly more of it. By switching to organic milk, the U.K. public could increase its average CLA intake by as much as 40 percent, the authors reckon.
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In the region covered by the study, all dairy cows got fresh grass in summer; the nutritional differences in the resulting milk stem, evidently, from the fact that organic cows get more grass. Here in the United States, large-scale industrial dairies have moved almost exclusively to year-round confinement systems based on corn. So, according to the logic of the study, conventionally raised U.S. milk would have even lower levels of desirable fats than conventional U.K. milk.
http://www.grist.org/article/food-2011-01-19-uk-study-organic-milk-has-healthier-fat-profile