Open Access

Comment on Oral White Lesions Associated with Chewing Khat

Tobacco Induced Diseases20053:5

DOI: 10.1186/1617-9625-3-1-5

Published: 15 December 2005

Dear Editor,

I have read the nice paper published in your estimable journal of Tobacco Induced Diseases Vol. 2, No. 3: 145-150 (2004) about "Oral White Lesions Associated with Chewing Khat". This was a clinical descriptive study done by Gorsky et al. on 47 Yemeni Israeli who had chewed khat more than 3 years and 55 Yemeni non-chewers as group control.

I kindly wanted to express my thoughts about some points mentioned in the paper including:

1. The phrase [chewing khat] mentioned in the paper is a misnomer and should be replaced by "takhzeen al-qat" as chewing does not infer the exact meaning of what Yemeni people used to do. They used to do "takhzeen" which means in Arabic chewing and storing of qat for several hours. Therefore, the Arabic word takhzeen is used to properly describe this habit1. And the word qat with letter "q" is more commonly used than khat, particularly in the recent studies [13].

2. The authors addressed people who chewed qat for more than 3 years (neglecting the frequency) as chronic chewers, in fact chronocity is dependent on two main factors; the duration (time in years), and frequency of chewing per week. For instance, many persons may use qat for more than 10 years in low frequency (once per month), yet, not considered as chronic users. On the other hand, others may practise it daily for only 2 years and considered as chronic. A recent study strongly correlated the effect of this habit with the frequency

3. The authors mentioned in their study a very exaggerated percentages of white lesions in both control (16%) and chewer (83%) groups. Whereas the highest international reported incidence4 of oral white lesions among the normal population is not more than 11.6% and among qat chewers1 (n = 1528) is 22.3%. Furthermore, the authors did not mention any description for the white lesions they found in the control group. What types of white lesions were found?

4. The authors addressed 14.6% of the diagnosed white lesions as non-homogenous, at the same time they said "No white lesion was felt to be clinically suspicious for malignant or premalignant changes", on the other hand, non-homogenous white lesions are considered in the international reports as aggressive lesions [57]. Moreover, the occurrence of such lesions is in contrary with most of other studies which reported that takhzeen al-qat may only cause homogenous or benign changes in the oral and esophagus mucosa [1, 810].

5. Finally, all recent references cited in this paper are not related to qat habit but to other habits in other regions of the world. While authors did not quote several studies done in the last 10 years on this habit in the Middle East, which are available through the Medline[13, 11, 12].

Looking forward to hearing from you

Yours sincerely

Ali A. A.


Authors’ Affiliations



  1. Ali Aiman, Al-Sharabi AK, Aguirre JM, Nahas R: A study of 342 oral keratotic white lesions induced by takhzeen al-qat among 2500 Yemeni. J Oral Pathol Med. 2004, 33: 368-72.View ArticlePubMed
  2. Hassan NM, Gunaid AA, Abdulla AA, Abdulkader ZY, Almansoob MK, Awad AY: The effect of qat chewing on blood pressure and heart rate in healthy volunteers. J Trop Doc. 2000, 30: 107-108.
  3. Al-Hadrani A, Thabet AAM: Acute adverse health effects of pesticides sprayed on qat trees. J Pest. Control and Enveron. Science. 2000, 8 (1): 97-106.
  4. Aiman A: Evaluación de pará metros clinico-patológicos de importancia pronóstica en la leucoplasia oral. Tesis Doctoral. 1997, Leioa (Spain): Universidad del País Vasco/EHU, 11-12.
  5. Waal van der I, Schepman KP: A modified classification and staging systems for oral leukoplakia. Oral Oncol. 2000, 36: 264-266. 10.1016/S1368-8375(99)00092-5.View ArticlePubMed
  6. Axell T, Pindborg JJ, Smith CJ, Wall van der I: International collaborative group on oral white lesions with special reference to precancerous and tobacco related lesions: Conclusion of an international symposium held in Uppsala, Sweden. J O Pathol Med. 1996, 25: 49-54. 10.1111/j.1600-0714.1996.tb00191.x.View Article
  7. Axell T, Holmstrup P, Kramer IR, Pindborg JJ, Shear M: International seminar on oral leukoplakia and associated lesions to tobacco habits. 1983. Malmo Comm Dent Oral Epidemiol. 1984, 12: 145-154. 10.1111/j.1600-0528.1984.tb01428.x.View Article
  8. El-Gunaid A, El-Sherif AN, Murray-Lyon IM, Zureikat N, SHUSHA S: Effect of chewing qat on the mucosal histology and prevalence of helicobacter pylori in the esophagus, stomach and duodenum of Yemeni patients. Histology. 1991, 19: 437-443.
  9. Ali Aiman: Common oral diseases related to qat chewing in Yemen. Journal of Damascus University (Arabic). 2003, 19 (1): 143-159.
  10. Ali Aiman, Ali A. Al-Sharabi: A pilot study on the histopathological changes in oral mucosa induced by takhzeen al-qat. Journal of Damascus University (Arabic). 2004, 20 (1): 217-229.
  11. Attef OA, Ali AA, Ali HM: Effect of khat chewing on bioavailability of ampicillin and amoxicillin. J Antimicro Chemoth. 1997, 39: 523-525. 10.1093/jac/39.4.523.View Article
  12. Nasher AA, Qirbi AA, Ghafoor MA: Khat chewing and neck bladder dysfunction. A randamised controlled trial of -adrenergic blockade. Br J Urology. 1995, 75: 597-598. 10.1111/j.1464-410X.1995.tb07415.x.View Article


© Aiman; licensee BioMed Central Ltd. 2005

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