Read the main article on Kenyan Christians defending khat.

Khat use has rarely been studied clinically and “has largely escaped medical attention,” according to Farrah J. Mateen and Gregory D. Cascino, two doctors who wrote a 2010 study in Mayo Clinic Proceedings, the journal of the Mayo Foundation for Medical Education and Research.

“Chewing the leaves of the plant Catha edulis,” Mateen and Cascino wrote, “likely dates to times of antiquity and may predate the use of coffee.” They compare the active ingredient in fresh khat leaves, cathinone, to amphetamine, identifying it as having “euphoric and mood-altering effects among other health consequences.” (The cathinone in the plant deteriorates as the leaves dry.)