At dinner last night, we were discussing how to avoid Mad Cow Disease. Some at the table are shunning beef entirely, while I've heard that only neural tissue (spine, brain) are a problem. It was argued by some that all beef is risky, because some might come from "closer to the bone".
The following is a response from Chowhound Technical Advisor (and PhD biochemist) Pierre Jelenc...who affirms that meat is ok, but spine/brain are not (also: you might avoid ground meat---which, who knows, may contain neural tissue---and shun restaurants (mostly Middle Eastern) which serve brain or spine, since the infection is impervious to heat and therefore all cooking surfaces/implements may be infected.
re: neural tissue:
States that "in the main: brain, spinal cord, eye and parts of the gut. Infectivity has not been detected in lymphoid tissues, other organs, or milk."
The eyes and parts of the gut are embryologically derived from the same precursors as the central nervous system
states that "Beef, milk and bones: Mouse assay tests have not detected BSE infectivity in muscle meat (beef) or milk from confirmed BSE cows. Experiments so far using the more sensitive calf assay are encouraging as regards beef and milk, but have some years still to go. Although, therefore, it is not yet known if beef or milk from BSE-infected cows contain amounts of BSE infectivity too small to be detected by mouse assay, current risk from beef or milk is considered to be extremely small. The same calf experiments have detected infectivity in the dorsal root ganglia, the trigeminal ganglia and the bone marrow. Risk assessment has indicated that the risk involved to people eating beef is extremely low, about one new case of variant CJD in a billion years per person. However the risk estimate has a wide range of uncertainty. The UK Government responded by banning the sale of bone-in beef"
A good intro is at: http://www-micro.msb.le.ac.uk/335/Pri...
Prions are not present in muscle, they are a neuron protein. What does "closer to the bone" have to do? It's not an action at a distance, and bones don't contain significant amounts of nerve. I don't get it.
There's no hocus pocus. The protein is integral part of the nerves (present mostly at the synapse), it is not expressed in non-nerve or nerve-equivalent tissue (eye, etc), it's never been found in muscle in numerous studies, and you can believe they've looked!