Prions Found in Dairy

According to the latest McDougall newsletter, prions have been found in dairy milk in Switzerland. Prions, of course, are those oddly folded proteins which cause mad cow and its variants. Here's the excerpt from the newsletter:

Mad Cow Proteins Detected in Dairy Products

Prion protein in milk by Nicola Franscini published in the December 2006 issue of PLoS ONE (Public Library of Science) found prion proteins in Swiss off-the-shelf milk and fresh milk.1 Prions are the cause of transmissible spongiform encephalopathies (TSE), such as bovine spongiform encephalopathy (BSE) in cattle and humans, and Creutzfeldt-Jakob disease (CJD) in humans. About the same concentration of prion protein was measured for organic farm milk and non-organic farm milk as well as for pasteurized (heating for 30 seconds to 72°C) and ultra-high temperature (UHT) treated (heating for 1–4 seconds to 135°C) milk.1 Prions were also found in the milk of humans, sheep, and goats.

Comment:

Prion protein is the agent that causes mad cow disease in cattle, people, deer, sheep, and many other animals. These infectious proteins accumulate for years before illness appears. Transmission from food to people is of great concern. Prior to the use of the latest technology, this infectious agent was hard to detect in milk. However, that changed with the use by these investigators of new methods employing the Alicon PrioTrap®. This technology is so effective that prion proteins can even be found in human milk.

A similar story can be told about bovine leukemia viruses found in cow’s milk. This virus was discovered in cattle in 1969, but studies using older technology (agar gel immunodiffusion and complement fixation assays) failed to find antibodies to bovine leukemia viruses in people. As a result, the prevailing opinion was exposure of humans to bovine leukemia viruses by eating beef and drinking cow’s milk was not important; therefore, the presence of this virus in our food supply was not a public health hazard.2 However, in 2003 researchers reported finding evidence of infection with bovine leukemia viruses in 74% of people tested by using more modern technology (immunoblotting).2 Still, almost no one has heard that 9 out of 10 cattle herds in the US are infected with bovine leukemia viruses and that three-fourths of people show immunologic signs suggesting infection.2

You should assume cow’s milk off-the-shelf contains infectious agents (prions, viruses, and microbes), which can impose a health risk to you and your family. Cow’s milk is also high in saturated fat, cholesterol, and animal protein; factors known to cause serious human disease. There is no risk in avoiding cow’s milk—it provides no nutrients, specifically calcium and protein, which could not be better obtained from plant sources. (See these recent newsletters for further information: February 2007: When Friends Ask: "Where Do You Get Your Calcium?"; March 2007: When Friends Ask: "Why Don't You Drink Milk?")

1) Franscini N, El Gedaily A, Matthey U, Franitza S, Sy MS, Bürkle A, Groschup M, Braun U, Zahn R. Prion protein in milk. PLoS ONE. 2006 Dec 20;1:e71.

2) Buehring GC, Philpott SM, Choi KY. Humans have antibodies reactive with Bovine leukemia virus. AIDS Res Hum Retroviruses. 2003 Dec;19(12):1105-13.

The entire newsletter can be read here:
http://www.drmcdougall.com/misc/2008nl/mar/fav5.htm

Looks like I'm going vegan.