Qat, also known as khat, is a plant whose fresh leaves and young shoots are chewed to produce a mild to moderate stimulant effect. This practice is deeply rooted in the cultural and social traditions of communities in East Africa and the Arabian Peninsula. While the effects are temporary, its widespread use has generated significant interest from a public health perspective globally. This article examines the biological mechanisms of qat, the resulting short-term and long-term health effects on the human body, and the plant’s varied legal status around the world.
The Qat Plant and Its Active Chemistry
Qat is derived from the shrub Catha edulis, a flowering evergreen native to the regions where its use is most common. The plant produces several psychoactive alkaloids, but the primary stimulant properties come from two compounds: cathinone and cathine. Cathinone is chemically similar to amphetamine and is the more potent psychoactive substance responsible for the plant’s initial stimulant effects.
The potency of the qat leaves is directly related to their freshness, which determines the concentration ratio of cathinone to cathine. Cathinone is unstable and rapidly breaks down after the leaves are harvested and begin to dry. Within approximately 48 hours of picking, cathinone largely decomposes into cathine, a significantly less potent stimulant. This chemical transformation is why consumers prefer fresh leaves and shoots, often keeping them wrapped to preserve moisture and maintain the cathinone concentration.
Immediate Effects on the Brain and Body
The immediate effects of chewing qat begin as the active alkaloids are released and absorbed through the mucous membranes in the mouth. Cathinone acts primarily as a sympathomimetic amine, meaning it mimics the effects of the body’s natural sympathetic nervous system activation. The compound structurally resembles amphetamine, allowing it to interfere with the reuptake and stimulate the release of certain neurotransmitters in the brain.
Cathinone specifically increases the levels of dopamine and norepinephrine in the central nervous system by acting on catecholaminergic synapses. This surge of neurotransmitters results in the characteristic psychological effects of euphoria, increased mental alertness, and a sense of excitement and energy. Users often report feeling more talkative and may experience insomnia after the effects wear off.
Physiologically, the drug’s sympathomimetic action causes a noticeable increase in heart rate and an elevation in blood pressure. These acute cardiovascular changes are a result of the alkaloids artificially stimulating the body’s “fight or flight” response. Qat chewing also causes appetite suppression. The peak psychoactive effects typically occur one to three hours after the chewing session begins, followed by a gradual decline in stimulation.
Chronic Health Consequences of Use
Long-term, heavy use of qat is associated with significant health risks across multiple body systems. The constant stimulation of the cardiovascular system can lead to serious complications, including chronic hypertension and an increased risk of acute events. Studies have linked chronic qat use to a higher incidence of myocardial infarction, stroke, and heart muscle disease, such as dilated cardiomyopathy. The persistent vasoconstriction and increased heart workload contribute significantly to this cardiac strain.
The localized practice of chewing the leaves creates specific oral and dental health problems. Regular chewers frequently develop periodontal disease, which involves inflammation and degradation of the gums. The abrasive nature of the plant material, combined with chemical exposure, can cause oral mucosal ulcers and permanent, greenish-brown staining and decay of the teeth. There is also an elevated risk of developing oral cancer, potentially due to the chronic abrasion and the presence of tannins in the plant.
Chronic consumption also affects the gastrointestinal tract, often resulting in severe constipation and the development of hemorrhoids. Psychologically, prolonged and heavy use can result in a pattern of dependence characterized by withdrawal symptoms like depression, anxiety, and lethargy when use is stopped. In vulnerable individuals, there is a risk of psychiatric manifestations, including anxiety disorders and a short-lived schizophreniform psychosis.
Usage Patterns and Global Legal Status
Qat is traditionally consumed by chewing the fresh leaves and shoots, which are held in the cheek and slowly masticated over several hours. This practice is deeply embedded in the social fabric of countries like Yemen and Ethiopia, where the chewing session often serves as a social ritual or a means to stay awake during work. It is widely used among men, though consumption patterns vary by region and social group.
The legal status of qat varies dramatically across different countries, reflecting a lack of international consensus on its classification. The World Health Organization classifies qat as a substance of abuse that can induce psychological dependence. Many nations have focused their legal control on the active chemical ingredients rather than the plant itself.
In the United States, for example, the primary psychoactive component, cathinone, is classified as a Schedule I controlled substance. Conversely, the less potent breakdown product, cathine, is subject to less restrictive controls. Most European and Asian countries have classified the plant or its active components as controlled substances. However, in its native growing regions, qat remains a significant agricultural commodity and a legal, culturally accepted stimulant.