Robert P. Friedland from University of Louisville School of Medicine in Louisville, KY and colleagues published a report in 2008 to suggest that dietary consumption of farmed fish may provide a means of transmission of infectious prion from cows suffering from bovine spongiform encephalopathy to consumers, eventually causing variant Creutzfeldt Jakob disease – the human form of mad cow disease.

Recycled use of animal protein is a known dangerous practice. Parts of farmed animals like cows (some are downers that die from diseases rather than are slaughtered) are processed and re-used into animal feeds intended for cows, chicken and shellfish/fish. This cycled use of animal proteins, particularly parts with prion protein, is officially considered the risk for mad cow disease. The U.S. government has long ago stopped monitoring prion disease or mad cow disease in the U.S., because it assumes that the risk of mad cow disease is no longer existent.

Authors of the report supported by the National Institutes of Health reviewed 10 reports on the potential risk from fish fed on animal protein which can include prion protein. Prion protein is very resistant to heat and sterilizing agents and cannot be destroyed easily. They suggest that “current regulations should be revised to ban the feeding of rendered material from cows to fish, until further work establishes the safety of this
practice.”

Ingested prion protein derived from animals will not immediately cause any disease. It takes decades for the human type of mad cow disease to manifest. The incubation time is so long that the association between prion protein consumption and the onset of mad cow disease could not be established. Also prion protein can not only result in mad cow disease, but also other neurodegenerative diseases like Alzheimer’s disease and Parkinson’s disease which many scientists believe have something to do with prion protein.

Eating animal foods – even fish – can be a risky business. The safe protein source should be the plants. Animal products like meats and cow milk are not just used as foods. Some like gelatin are commonly used in dietary supplements as a gelatinizing agent to form soft-gels. Gelatin is supposedly tested to make sure that prion protein does not show up. But there is no absolutely certainty to guarantee that a product is free of prion protein. (DR. Lu)

來自肯塔基州路易斯維爾路易斯維爾大學路易斯維爾大學醫學院的 Robert P. Friedland 及其同事在 2008 年發表了一份報告，認為養殖魚類的飲食消費可能提供一種將感染性朊病毒從患有牛海綿狀腦病的奶牛傳播給消費者的途徑，最終導致變異的克雅氏病——瘋牛病的人類形式。

循環使用動物蛋白是一種已知的危險做法。部分養殖動物，如奶牛（有些是死於疾病而不是被屠宰的動物）被加工並重新用作用於奶牛、雞和貝類/魚類的動物飼料。這種循環使用動物蛋白，特別是含有朊病毒蛋白的部分，被官方認為是瘋牛病的風險。美國政府早就停止在美國監測朊病毒病或瘋牛病，因為它認為瘋牛病的風險已經不存在了。

由美國國立衛生研究院支持的該報告的作者審查了 10 份關於以動物蛋白餵養的魚的潛在風險的報告，其中可能包括朊病毒蛋白。朊病毒蛋白對熱和消毒劑具有很強的抵抗力，不易被破壞。他們建議“應修改現行法規，禁止將提煉過的材料從奶牛餵給魚，直到進一步的工作確定這種材料的安全性。
實踐。”

攝入來自動物的朊病毒蛋白不會立即引起任何疾病。人類類型的瘋牛病需要幾十年的時間才能顯現出來。潛伏期太長，以至於無法確定朊病毒蛋白消耗與瘋牛病發病之間的關聯。此外，朊病毒蛋白不僅會導致瘋牛病，還會導致其他神經退行性疾​​病，如阿爾茨海默病和帕金森病，許多科學家認為這與朊病毒蛋白有關。

吃動物性食物——甚至是魚——可能是一件有風險的事情。安全的蛋白質來源應該是植物。肉類和牛奶等動物產品不僅用作食品。一些如明膠通常用於膳食補充劑中作為膠凝劑以形成軟凝膠。據推測，明膠經過測試以確保朊病毒蛋白不會出現。但是並不能絕對保證產品不含朊病毒蛋白。 （盧博士）