Khat

Khat, Catha edulis, is an evergreen shrub of the highlands of Ethiopia, Kenya and Yemen whose young leaves and shoots are chewed fresh for a mild stimulant effect, comparable to strong coffee with a longer and more talkative arc.

Its religious dimension is Sufi, and the reasoning behind it is the same reasoning that made coffee acceptable in the same region at roughly the same time. The orders of Yemen and the Horn of Africa held long night devotions, dhikr, requiring sustained wakefulness and concentration, and khat made that possible. Tradition in Yemen credits Sufi shaykhs with its introduction, and the plant's spread from Ethiopia into Arabia is bound up with the orders.

The legal argument that followed is instructive. Khat, like coffee, was debated by jurists for centuries as to whether it fell under the prohibition of intoxicants, and the arguments turned on whether it clouds the intellect or sharpens it. Opinion divided and never fully settled, which is why khat is unremarkable in Yemen and Somalia and forbidden in Saudi Arabia.

Outside the devotional setting its use is overwhelmingly social and daily. Afternoon sessions in a dedicated room, with a specific etiquette and a recognised arc from talk to quiet, structure a great deal of ordinary Yemeni life, and the sessions are where business and disputes are conducted.

Khat has one property that has shaped everything about it: the active compound cathinone degrades within a couple of days of picking, converting to a much weaker substance. The leaf must be consumed fresh.

For most of its history that confined khat to its growing regions and their immediate surroundings, and it is why khat, unlike coffee, never became a global commodity despite a comparable history and an easier preparation. Modern air freight changed this, and daily flights carrying khat from Ethiopia and Kenya to diaspora communities created an export trade of real economic weight, followed by bans in the United Kingdom, the Netherlands and elsewhere that removed it again.

The consequences at the growing end are substantial. Khat is far more profitable than coffee or food crops and it is harvested continuously rather than seasonally, so it has displaced both across large areas of Yemen and Ethiopia. In Yemen it consumes a very large share of scarce irrigation water in one of the most water-stressed countries in the world, which makes it a factor in food security rather than only a social question.

Its harms are contested and appear to be real but moderate: dependence, dental and oral problems, sleep disruption and cardiovascular effects, with psychiatric effects reported at heavy use. The atlas records the Sufi devotional use as its religious dimension, and notes that this is now a small part of a much larger and largely secular practice.