The brain is composed of 60% fat. It is the fattiest organ in the body. Much of the fat required by the brain to function properly is DHA. DHA is called an essential fatty acid because the body cannot manufacture it, instead it requires it from the diet. DHA is a polyunsaturated fatty acid, which means it is liquid at room temperature and subject to oxidation. The only kind of DHA you want to ingest is the unoxidized. Due to industrial methods of processing 99% of the Fish Oil supplements on the market are highly oxidized. Learn about the one and only Cod Liver Oil on the market not subjected to heated and protected with Rosemary oil and vitamin E.