Influence of Regular Black Tea Consumption on Tobacco Associated DNA Damage and HPV Prevalence in Human Oral Mucosa

Abstract

Black tea is more widely consumed than green tea worldwide, particularly in India. Therefore, it is necessaryto focus attention on black tea with respect to its health promoting and anti-cancer actions. In order to establishthe concept that black tea is a potential candidate for cancer prevention, it is important to provide epidemiologicalevidence derived from investigations of human populations. In view of this, the objective of the present studywas to determine the correlation between nature of black tea consumption and DNA damage in normal subjectswith or without tobacco habit and oral cancer patients, taking the latter as positive controls. Much experimentalevidence points to associations between tobacco habit and HPV 16 and HPV 18 (Human Papilloma virus) infection.But no studies have taken into account the possible confounding effect of black tea consumption on DNA damagealong with HPV infection. A pilot study was therefore undertaken. Comet assay was used to evaluate the DNAdamage among normal subjects including tobacco users (n = 86), non-tobacco users (n = 45) and Oral cancerpatients (n = 37). Percentage of damaged cells was scored in the buccal squamous cells of all subjects mentionedabove. HPV analysis was performed on 79 samples (including 37 oral cancer patients). The evaluation of variousconfounding factors like age, tenure of tobacco habit and tea habit showed significant associations with DNAdamage. The observations strongly indicate that regular intake of black tea at least above four cups can reducetobacco associated DNA damage among normal tobacco users. HPV prevalence was not seen to be associatedwith age, tenure of tobacco habit or the tea drinking habit.