Khat-related liver disease in sub-Saharan Africa: neglected, yet important – Authors' reply
Authors: Sandro Vento, Bartholomew Dzudzor, Francesca Cainelli, Kenneth Tachi
Journal: The Lancet Global Health (2019)

We thank Stian Orlien and colleagues for raising attention to the issue of khat use as a recreational drug in sub-Saharan Africa in response to our Comment.1Vento S Dzudzor B Cainelli F Tachi K Liver cirrhosis in sub-Saharan Africa: neglected, yet important.Lancet Glob Health. 2018; 6: e1060-e1061Summary Full Text Full Text PDF PubMed Scopus (23) Google Scholar Although we mentioned the fact that traditional herbal medicine could contribute to the burden of cirrhosis in this region, as the use of khat is associated with a substantial increase in liver fibrosis,2Orlien SMS Ismael NY Ahmed TA et al.Unexplained chronic liver disease in Ethiopia: a cross-sectional study.BMC Gastroenterol. 2018; 18: 27Crossref PubMed Scopus (13) Google Scholar we do not think that the available evidence shows that khat is a major contributor to chronic liver disease. Khat is used in parts of east Africa, including Djibouti, Ethiopia, Somalia, Somaliland, Kenya, Sudan, Uganda, and Madagascar. Apart from its long-standing popularity as a recreational drug, it can be used for the treatment of erectile dysfunction, malaria, influenza, vomiting, and headache.3WHOAssessement of khat (Catha edulis Forsk).https://www.who.int/medicines/areas/quality_safety/4.4KhatCritReview.pdfDate: 2006Date accessed: October 25, 2018Google Scholar The Central African Republic, Gabon, and Côte d'Ivoire were in the top 10% of countries for cirrhosis-related deaths in 2010 but khat use is uncommon in west or central Africa.4Acuda W Othieno CJ Obondo A Crome IB The epidemiology of addiction in sub-Saharan Africa: a synthesis of reports, reviews, and original articles.Am J Addict. 2011; 20: 87-99PubMed Google Scholar The question of khat's liver toxicity is complex. It contains numerous compounds, including alkaloids, terpenoids, flavonoids, sterols, glycosides, tannins, amino acids, vitamins, and minerals.5Kalix P Braenden O Pharmacological aspects of the chewing of khat leaves.Pharmacol Rev. 1985; 37: 149-164PubMed Google Scholar Research into the deleterious effects of khat has largely concentrated on the pharmacological effects of cathinone and cathine on the cardiovascular system and CNS, and studies on possible liver toxicity in humans are restricted to Ethiopia and Somaliland and to reports from western Europe almost exclusively involving Somali men. Additional research is necessary to establish the prevalence of liver toxicity in people who chew khat in Ethiopia versus Djibouti (where liver toxicity is apparently not observed)6Coton T Simon F Oliver M Kraemer P Hepatotoxicity of khat chewing.Liver Int. 2011; 31: 434Crossref PubMed Scopus (11) Google Scholar and Yemen (which has the highest proportion of users worldwide),7Al-Mugahed L Khat chewing in Yemen: turning over a new leaf.Bull World Health Organ. 2008; 86: 741-742Crossref PubMed Scopus (56) Google Scholar and in Kenya, Uganda, and Madagascar, where studies have not been done. Also necessary is investigating the mechanisms and progression of liver damage induced by khat, the effects of gender (khat toxicity is observed much more frequently in males)8Orlien SMS Sandven I Berhe NB et al.Khat chewing increases the risk for developing chronic liver disease: a hospital-based case-control study.Hepatology. 2018; 68: 248-257Crossref PubMed Scopus (11) Google Scholar and genetics (genetic variants in CYP2D6 might play a role in liver toxicity),9Sharma A Orlien SMS Abdosh AT et al.PWE-082 genetic variants in CYP2D6 and the propensity to chronic liver disease in men chewing khat.Gut. 2018; 67: A113Google Scholar and the contribution of other compounds found in khat and of contaminating herbicides and pesticides to liver disease.10Al-Akwa AA Shaher M Al-Akwa S Aleryani SL Free radicals are present in human serum of Catha edulis Forsk (khat) abusers.J Ethnopharmacol. 2009; 125: 471-473Crossref PubMed Scopus (24) Google Scholar Current evidence shows that hepatitis viruses and alcohol are the main contributors to the incidence of liver cirrhosis throughout sub-Saharan Africa1Vento S Dzudzor B Cainelli F Tachi K Liver cirrhosis in sub-Saharan Africa: neglected, yet important.Lancet Glob Health. 2018; 6: e1060-e1061Summary Full Text Full Text PDF PubMed Scopus (23) Google Scholar and efforts should continue to curb their effects. We declare no competing interests. Liver cirrhosis in sub-Saharan Africa: neglected, yet importantClinical efforts and research on liver diseases have been scarce in sub-Saharan Africa. The first Conference on Liver Disease in Africa (Nairobi, Sept 13–15, 2018), gathering all stakeholders from the continent, is a welcome step towards greater attention to the problem, and the important issue of liver cirrhosis. Full-Text PDF Open AccessKhat-related liver disease in sub-Saharan Africa: neglected, yet importantIn their Comment, Sandro Vento and colleagues (October, 2018)1 highlight cirrhosis as an important but neglected health issue in sub-Saharan Africa. We endorse their call for greater public awareness of this emerging health issue, for governmental commitment to facilitate pertinent preventative efforts in public health, and for better diagnostic and treatment options. However, we were surprised that they did not mention what is, without a doubt, one of the most important emerging causes of chronic liver disease in this region, namely the recreational use of khat (Catha edulis). Full-Text PDF Open Access