Trans Fats & Milk Products
There are substantial differences between the trans fats that occur naturally in ruminant (animal) fats and those derived from vegetable fats and oils. Not only is the hydrogenation process radically different, but so are the types and amounts of trans fats created.
Natural trans fats are found in very small quantities in the meat and milk of ruminant (cows, sheep, goats) animals. These trans fats are produced by the normal bacterial action in the animal's stomach. Natural trans fats are not linked to health problems, contrary to industrial trans fats.
The Hydrogenation Process
Unsaturated fats eaten in plants by ruminant animals undergo biohydrogenation via bacteria found in rumen. The process is natural, aided by bacterial enzymes at normal body temperature under normal body pressure. Naturally occurring ruminant trans fats have been in the food supply since animals were first domesticated to provide food - at least 10,000 years ago.
In contrast, industrial trans fats are formed when vegetable oil is converted into solids through the chemical process of hydrogenation. This process is initiated by metal catalysts under enormous pressure at very high temperatures. Widespread only since the late 1940s, many of these trans fats had never been encountered before in nature or existed only in trace amounts.
Source: Dairy Farmers of Canada www.dairygoodness.ca