Summary Catha edulis (khat) is a plant grown in the countries around the Red Sea and on the eastern coast of Africa. Its leaves are chewed by the local people for their stimulant action. Its principal active constituents are cathinone and cathine, which have sympathomimetic actions. Migration of Africans from these countries has spread the habit of khat chewing to the West. Chewing khat has a number of important psychological and physical sequelae. ‘Khat-related’ psychosis is very similar to that seen following use of amphetamines.
Khat grows wild in countries bordering the Red Sea and along the east coast of Africa. The people of these countries have chewed khat for centuries. There are several names for the plant, depending on its origin: chat, qat, qaad, jaad, miraa, mairungi, cat and catha. In most of the Western literature, it is referred to as khat.
Khat is an evergreen shrub, which is cultivated as a bush or small tree. The leaves have an aromatic odour. The taste is astringent and slightly sweet. The plant is seedless and hardy, growing in a variety of climates and soils. Khat can be grown in droughts where other crops have failed and also at high altitudes. It is harvested throughout the year. Planting is staggered to obtain a continuous supply (Luqman & Danowski, 1976). Khat is mainly grown in Ethiopia, Kenya, Yemen, Somalia, Sudan, South Africa and Madagascar. It has also been found in Afghanistan and Turkestan. Previously, khat leaves were available only near to where they were grown. Recently, improved roads and air transport have allowed a much wider distribution. Khat is harvested in the early hours of the morning and sold in markets in late morning. It is presented as a bundle of twigs, stems and leaves, wrapped in banana leaves to preserve freshness (Fig. 4.1).
History of consumption and ‘medical’ use
Ethiopia is thought to be the country of origin of khat use. The chewing of khat leaves probably pre-dates the use of coffee. The earliest written record of the medical use of khat appears to be in the New Testament. Khat has been used to treat various ailments, including relieving the symptoms of depression. Some believe it to be a dietary requirement.