Staple foods from the third world, such as cassava, maize, bamboo shoots, sweet potatoes, lima beans and millets, contain cyanogenic glucosides that are capable of liberating large quantities of cyanide by hydrolysis. Not only is the cyanide itself toxic, but the metabolites formed in the body from cyanide is predominantly thiocynanate, which is goitrogen causing goitre. With the exception of cassava, these glycosides are located in the inedible portion. If present in the edible portion, they are present in such small quantities that they do not cause a major problem. Cassava, on the other hand, is cultivated extensively in developing countries and represents and essential source of energy for more than 200 million people living in the tropics.