Oral White Lesions Associated with Chewing Khat
Meir Gorsky 1,   Joel B. Epstein 2, 3  
,   Harel Levi 4,   Noam Yarom 1
More details
Hide details
Department of Oral Pathology and Oral Medicine, The Maurice and Gabriella Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel
Medical-Dental Staff, British Columbia Cancer Agency, Vancouver, Canada
Department of Oral Medicine and Diagnostic Sciences, Chicago, USA
The Maurice and Gabriella Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel
Publication date: 2004-09-15
Tobacco Induced Diseases 2004;2(September):145
Khat is a cultivated plant whose leaves when chewed elevate mood. Unlike the chewing of betel nut, no association between the white oral mucosal lesions in khat users and oral malignancies has been reported. Chewing of khat has been documented in many countries and has increased with worldwide migration. The impact of chewing khat upon the oral mucosa is essentially unknown.

The purpose of this study was to assess the occurrence of oral white changes in chronic khat chewers. Oral mucosal changes in a group of 47 Yemenite Israeli men over 30 years of age, who had chewed khat more than 3 years, were compared to those of 55 Yemenite men who did not chew.

White lesions were significantly more prevalent in the khat chewers (83%) compared to the non chewing individuals (16%) (P < 0.001). White oral lesions were identified primarily on the lower buccal attached gingival mucosa, the alveolar mucosa and the lower mucobuccal fold on the chewing side (p < 0.001). There was no significant association between the occurrence of the white lesions and smoking. Even though the majority of the white lesions (85.4%) were homogenous, 71.4% of the non homogenous lesions were identified in khat chewers. Vital staining with toluidine blue and exfoliative cytology was conducted on a subset of patients with homogenous and non-homogenous oral lesions, and there were no findings suspicious for pre-malignant or malignant changes.

This study demonstrated a relationship between khat chewing and oral white lesions, which we attribute to chronic local mechanical and chemical irritation of the mucosa. Our findings also suggest that mucosal changes associated with khat are benign, however, this initial study requires further studies including follow-up of khat users to confirm the current findings, including the likely benign changes associated with chronic use and histologic findings of clinical lesions.

McKee CM: Medical and social aspects of qat in Yemen: a review. Journal of the Royal Society of Medicine. 1987, 80 (12): 762-5.
Hill CM, Gibson A: The oral and dental effects of q'at chewing. Oral Surgery, Oral Medicine, Oral Pathology. 1987, 63 (4): 433-6. 10.1016/0030-4220(87)90255-6.
Ashri N, Gazi M: More unusual pigmentations of the gingival. Oral Surgery, Oral Medicine, Oral Pathology. 1990, 70 (4): 445-9. 10.1016/0030-4220(90)90207-9.
Kennedy JG, Teague J, Rokaw W, Cooney E: A medical evaluation of the use of qat in North Yemen. Social Science & Medicine. 1983, 17 (12): 783-93. 10.1016/0277-9536(83)90029-1.
Halket JM, Karasu Z, Murray-Lyon IM: Plasma cathinone levels following chewing khat leaves (Catha edulis Forsk.). Journal of Ethnopharmacology. 1995, 49 (2): 111-3. 10.1016/0378-8741(95)90038-1.
Elmi AS: The chewing of khat in Somalia. Journal of Ethnopharmacology. 1983, 8 (2): 163-76. 10.1016/0378-8741(83)90052-1.
Halbach H: Medical aspects of the chewing of khat leaves. Bulletin of the World Health Organization. 1972, 47 (1): 21-9.
Kalix P, Braenden O: Pharmacological aspects of the chewing of khat leaves. Pharmacological Reviews. 1985, 37 (2): 149-64.
Al-Bekairi AM, Abulaban FS, Qureshi s, Shah AH: The toxicity of catha edulis (Khat). A review. Fitoterapia. 1991, 62 (4): 291-300.
Nencini P, Ahmed AM, Elmi AS: Subjective effects of khat chewing in humans. Drug & Alcohol Dependence. 1986, 18 (1): 97-105. 10.1016/0376-8716(86)90118-3.
Norton SA: Betel: consumption and consequences. Journal of the American Academy of Dermatology. 1998, 38 (1): 81-8. 10.1016/S0190-9622(98)70543-2.
Gupta PC, Pindborg JJ, Mehta FS: Comparison of carcinogenicity of betel quid with and without tobacco: an epidemiological review. Ecology of Disease. 1982, 1 (4): 213-9.
Soufi HE, Kameswaran M, Malatani T: Khat and oral cancer. Journal of Laryngology & Otology. 1991, 105 (8): 643-5.
Macigo FG, Mwaniki DL, Guthua SW: The association between oral leukoplakia and use of tobacco, alcohol and khat based on relative risks assessment in Kenya. European Journal of Oral Sciences. 1995, 103 (5): 268-73. 10.1111/j.1600-0722.1995.tb00025.x.
Hes JP: The use of Catha edulis among Yemenite Jews. [Hebrew]. Harefuah. 1970, 78 (6): 283-4.
Kalix P: Khat-a dangerous drug?. [Hebrew] Harefuah. 1990, 118 (9): 555-6.
Axell T, Pindborg JJ, Smith CJ, Waal van der I: Oral white lesions with special reference to pre-cancerous and tobacco-related lesions: conclusions of an international symposium held in Uppsala, Sweden, May 18–21, 1994. J Oral Pathol Med. 1996, 25: 49-54. 10.1111/j.1600-0714.1996.tb00191.x.
Waal van der I, Axell T: Oral leukoplakia: a proposal for uniform reporting. Oral Oncol. 2002, 38: 521-6. 10.1016/S1368-8375(01)00125-7.
Gorsky M, Buchner A, Moskona D, Aviv I: Physiologic pigmentation of oral mucosa in Israeli Jews of different ethnic origin. Community Dentistry and Oral Epidemiology. 1984, 2: 188-190. 10.1111/j.1600-0528.1984.tb01436.x.
Martin JL: Leukoedema: a review of the literature. Journal of the National Medical Association. 1992, 84 (11): 938-40.
Yang YU, Lee HY, Tung S, Shieh TY: Epidemiological survey of oral submucous fibrosis and leukoplakia in aborigines of Taiwan. Journal of Oral Pathology & Medicine. 2001, 30 (4): 213-9. 10.1034/j.1600-0714.2001.300404.x.
Betel-quid and areca-nut chewing and some areca-nut related nitrosamines. IARC Monogr Eval Carcinog Risk Hum. 2003, 85: 11-18.
Trivedy CR, Craig G, Warnakulasuriya S: The oral health consequences of chewing areca nut. Addict Biology. 2002, 7: 115-25. 10.1080/13556210120091482.
Wu MT, Lee YC, Chen CJ, Yang PW, Lee CJ, Wu DC, et al: Risk of betel chewing for oesophageal cancer in Taiwan. Brit J Cancer. 2001, 85: 658-60. 10.1054/bjoc.2001.1927.
Chen YK, Huang HC, Lin LM, Lin CC: Primary oral squamous cell carcinoma: an analysis of 703 cases in southern Taiwan. Oral Oncol. 1999, 35: 173-9. 10.1016/S1368-8375(98)00101-8.
Chang KC, Su IJ, Tsai ST, Shieh DB, Jin YT: Pathological features of betel quid-related oral epithelial lesions in Taiwan with special emphasis on the tumor progression and human papillomavirus association. Oncology. 2002, 63: 362-9. 10.1159/000066227.
Reichard PA, Philipsen HP: Betel chewers' mucosa – a review. Journal of Oral Pathology and Medicine. 1998, 27 (6): 239-42.
Daftary DK, Bhonsle RB, Murti PR, Pindborg JJ, Metha FS: An oral lichen planus-like lesion in Indian betel-tobacco chewers. Scand J Dent Res. 1980, 88 (3): 244-9.
Reichart PA, Schmidberg W, Scheifele C: Betel chewer's mucosa in elderly Cambodian women. Journal of Oral Pathology and Medicine. 1996, 25 (7): 367-70. 10.1111/j.1600-0714.1996.tb00280.x.
Mehta FS, Pindborg JJ, Hamner JE: Oral cancer and precancerous conditions in India. 1971, Copenhagen: Munksgaard, 17.
Epstein JB, Feldman R, Dolor RJ, Porter SR: The utility of tolonium chloride rinse in the diagnosis of recurrent or second primary cancers in patients with prior upper aerodigestive tract cancer. Head Neck. 2003, 25: 911-21. 10.1002/hed.10309.
Epstein JB, Zhang L, Poh C, Nakamura H, Berean K, Rosin M: Increased allelic loss in toluidine blue-positive oral premalignant lesions. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2003, 95: 45-50. 10.1067/moe.2003.97.
A Sciubba JJ: Improving detection of precancerous and cancerous oral lesions. Computer-assisted analysis of the oral brush biopsy. U.S. Collaborative OralCDx Study Group. JADA. 1999, 130: 1445-57.
B Svirsky JA, Burns JC, Carpenter WM, Cohen DM, Bhattacharyya I, Fantasia JE, Lederman DA, Lynch DP, Sciubba JJ, Zunt SL: Comparison of computer-assisted brush biopsy results with follow up scalpel biopsy and histology. Gen Dent. 2002, 50: 500-3.
C Scheifele C, Schmidt-Westhausen AM, Dietrich T, Reichart PA: The sensitivity and specificity of the OralCDx technique: evaluation of 103 cases. Oral Oncol. 2004, 40: 824-8. 10.1016/j.oraloncology.2004.02.004.
Khat chewing habit produces a significant adverse effect on periodontal, oral health: A systematic review and meta-analysis
M. S. Al-akhali, E. A. Al-Moraissi
Journal of Periodontal Research
Correlates of Nicotine Dependence in U.K. Resident Yemeni Khat Chewers: A Cross-Sectional Study
S. Kassim, S. Islam, R. E. Croucher
Nicotine & Tobacco Research
Khat (Catha edulis ) and its oral health effects: An updated review
Sadeq A. Al-Maweri, Saman Warnakulasuriya, Abdulaziz Samran
Journal of Investigative and Clinical Dentistry
The burden of oral cancer in sub-Saharan Africa
Jos Hille, Newell W Johnson
Translational Research in Oral Oncology
White oral mucosal lesions among the Yemeni population and their relation to local oral habits
Sadeq A. Al-Maweri, Aisha Al-Jamaei, Rajan Saini, Denise M. Laronde, Amany Sharhan
Journal of Investigative and Clinical Dentistry
Prevalence of oral white lesions due to qat chewing among women in Yemen
AM Schmidt-Westhausen, J Al Sanabani, AK Al-Sharabi
Oral Diseases
Family Context and Khat Chewing among Adult Yemeni Women: A Cross-Sectional Study
AL-abed Ali AL-abed, Rosnah Sutan, Sami Abdo Radman Al-Dubai, Syed Mohamed Aljunid
BioMed Research International
The Epidemiology of Tobacco Use among Khat Users: A Systematic Review
Saba Kassim, Mohammed Jawad, Ray Croucher, Elie A. Akl
BioMed Research International
Qat Chewing and Risk of Potentially Malignant and Malignant Oral Disorders: A Systematic Review
S El-Zaemey, J Schüz, ME Leon
The International Journal of Occupational and Environmental Medicine
Oral manifestations of habitual khat chewing: a case-control study
Noam Yarom, Joel Epstein, Harel Levi, Dalit Porat, Eliezer Kaufman, Meir Gorsky
Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology
Khat Chewing and Smoking Effect on Oral Mucosa: A Clinical Study
Essam Halboub, Essam Dhaifullah, Mahmoud Abdulhuq
Acta Medica (Hradec Kralove, Czech Republic)
Cytological study of exfoliative buccal mucosal cells of Qat chewers in Yemen
Hussain Gad Elkarim Ahmed, Ammar Saleh Abdullah Omer, Shadan Atif Abd algaffar
Diagnostic Cytopathology
Leukoplakia—A Diagnostic and Management Algorithm
Alessandro Villa, Sook Bin Woo
Journal of Oral and Maxillofacial Surgery
Oral symptoms significantly higher among long-term khat (Catha edulis) users in Ethiopia
Ayalew Astatkie, Meaza Demissie, Yemane Berhane, Alemayehu Worku
Epidemiology and Health
Clinical and cytological study of the oral mucosa of smoking and non-smoking qat chewers in Yemen
M. Hijazi, H. Jentsch, J. Al-Sanabani, M. Tawfik, T. W. Remmerbach
Clinical Oral Investigations
Oral Lesions Induced by Chronic Khat Use Consist Essentially of Thickened Hyperkeratinized Epithelium
Ochiba Mohammed Lukandu, Lionel Sang Koech, Paul Ngugi Kiarie
International Journal of Dentistry
Histopathologic changes in oral mucosa of Yemenis addicted to water-pipe and cigarette smoking in addition to takhzeen al-qat
Aiman A. Ali
Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology
Khat induces G1-phase arrest and increased expression of stress-sensitive p53 and p16 proteins in normal human oral keratinocytes and fibroblasts
Ochiba M. Lukandu, Daniela E. Costea, Elizabeth A. Dimba, Evelyn Neppelberg, Therese Bredholt, Bjørn T. Gjertsen, Olav K. Vintermyr, Anne C. Johannessen
European Journal of Oral Sciences
Known or Still Unknown Drug Khat. Reasons for and Consequences of Chewing Khat Leaves
Nabil Salah
Smokeless tobacco and oral cancer in the Middle East and North Africa: A systematic review and meta-analysis
Mir Quadri, Santosh Tadakamadla, Tenny John
Tobacco Induced Diseases
Catha edulis-induced skeletal muscle toxicity in experimental rats via regulation of rhabdomyolysis biomarkers
Syam Mohan, Emad Shaheen, YasminO El-Amir, HusseinA Khadashi, SaidaS Ncibi, Abdullah Farasani, SiddigIbrahim Abdelwahab
Pharmacognosy Magazine