A Food and Drug Administration (FDA) advisory panel has said it is possible that people taking some dietary supplements may be exposed to mad cow disease.

There is little hard evidence that dietary supplements could be contaminated by bovine spongiform ecephalopathy (BSE). However, the Transmissible Spongiform Encephalopathies Advisory Commission still thought the FDA should consider drawing up criteria to ask people about what supplements they take before they donate blood. 

The panel said no one should be barred from donating now, but that the supplement manufacturing process and source of ingredients should be closely monitored.

Committee members were concerned that some dietary supplements are made with brain or spinal cord tissue, or pituitary or other glandular tissue from cattle, especially from European cattle. The panel has suggested that people avoid any products made with these ingredients. Panelists also noted concern that supplement makers might import bovine products from countries with infected cattle.

“It’s important that we know these products are safe,” said panel chairman Paul Brown of the National Institutes of Neurological Disorders and Strokes, adding, “I think we’ve heard enough evidence to suggest that they may not be.”