Conjugated linoleic acid is the collective name given to a group of isomers of linoleic acid found principally in dairy fat and meat fat especially meat from ruminants. The fat-soluble vitamins are found mainly in the lipid fraction of fat-containing foods, and they are also absorbed along with dietary fat in the gut. The minimum human requirement for these essential fatty acids is extremely small and it is difficult to reproduce the symptoms of this deficiency disease of rats in deprivation studies with human volunteers. The eicosanoids are a range of regulatory molecules that are involved in the regulation of most physiological processes in the initiation of labour, blood platelet aggregation, blood vessel constriction/dilation, inflammation and many secretory processes. Glands at the base of the tongue produce a lingual lipase, an enzyme that works at low pH and can readily digest the fat in milk globules before emulsification by bile salts.