ABSTRACT
Fish contain a compound called trimethylamine N-oxide. They are believed to use it to increase osmotic concentration and thus depress the freezing point of body fluids, an important detail in cold-water fish. Toxic nitrogen compounds obtained from the diet are metabolized by enzymes and are ultimately converted into trimethylamine. Trimethylamine is a base, like ammonia. It seems that dogs sometimes smell of trimethylamine, while Swedish scientists have discovered the mutation in the flavinmonoxygenases (FMOs) gene causing some Swedish cows to produce fish-smelling milk. The plant called Stinking Goosefoot also produces trimethylamine. The body contains enzymes called FMOs which reside in the liver and are thought to break down environmental toxins in the body. Up to 1% of people are believed to contain a defective copy of the FMO3 gene, of which everyone has two copies, one inherited from each parent.
