Some herbal and nutritional supplements contain extracts from cattle that have the potential to be contaminated with the agent that causes mad cow disease and is believed to also cause Creutzfeldt-Jakob (CJD) disease in humans. The risk is very low, but the U.S. Food and Drug Administration (FDA) has expressed safety concerns to manufacturers and importers of supplements.
The Orange County Register explains that tissues or extracts from the brains and spinal cords of cattle have the highest risk for transmitting the prion believed to cause CJD. The article also ranks other cattle tissues into medium- and low-risk categories.
In 1994, Congress revoked most of FDA's authority to regulate vitamins and dietary supplements. That means manufacturers don't need to test most products for safety. This puts the burden on consumers, who should read labels carefully to spot ingredients derived from animal sources.
Supplement makers, however, sometimes list only a generic ingredient such as "animal protein" without specifying whether cattle were used or the country of origin for ingredients.
The United Kingdom accounts for nearly all of the human deaths linked to contaminated cattle. Last year, however, the World Health Organization warned that contaminated cattle or cattle products could start spreading beyond western Europe, the CBC News reports.
