One reason for this is the thiaminase enzyme in fish...it destroys thimaine (Vitamin B1). 一个理由这样做是，在鱼体内有硫胺酶的消化酶，他可以会破坏维他命B1。
Fish especially rich in thiaminase are herring, capelin, suckers, smelts and various carp species, a total of some 50 species, most of which live in fresh water. 鱼类中，最富含硫胺酶的是青鱼，各种鲤鱼等总共有50种，他们大部分都是生活在优质的水域。
