title: Does green tea consumption improve the salivary antioxidant status of smokers?
abstract: OBJECTIVE
  Considering the higher rate of oral cancer, and reduction in salivary antioxidants in smokers as indicated in previous studies, antioxidant- containing nutrients such as green tea, seem to be beneficial in counteracting against oxidative stress in this group. This study assessed the salivary total antioxidant alteration in smokers compared to nonsmokers, after short-tem (7days) and long-term (3 weeks), green tea drinking.
  
  
  METHODS
  In this experimental study, 20 volunteer moderate-to-heavy male smokers, and 20 matched healthy non-smokers were selected to participate, according to the inclusion criteria. Participants were instructed to drink two cups of green tea per day, by dissolving 2g of green tea in 150ml of hot water for each cup. After saliva collection, antioxidant capacity of saliva was measured at baseline, after 7days, and after 21days. Statistical evaluation was done by SPSS 21, using paired samplet tests, one-way ANOVA and Bonferroni tests.
  
  
  RESULTS
  At day zero nonsmokers had a higher antioxidant capacity than smokers (686.6±62.22 vs. 338.8±59.9) mM/50μl, P<0.001. There was also a significant difference between two groups in salivary total antioxidant capacity after one week and three weeks of green tea consumption (P<0.001). However, there was an upward trend in both smokers and non-smokers over the study period (after tea drinking). In addition, a significant difference was found in total antioxidant capacity alteration in smokers compared to non-smokers from baseline to day 21.
  
  
  CONCLUSIONS
  Results support the effectiveness of green tea consumption in salivary antioxidants enhancement in smokers, in both the short- and long term.
authors.affiliation: International Research Collaborative - Oral Health and Equity, School of Anatomy, Physiology and Human Biology, University of Western Australia, WA, Crawley, Australia.
authors.forename: Somayyeh
authors.initials: S
authors.lastname: Azimi
authors.affiliation: Department of Oral Medicine, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Zahra
authors.initials: Z
authors.lastname: Mansouri
authors.affiliation: Department of Oral Medicine, Dental School, Shahid Beheshti University of Medical Sciences, Tehran, Iran. Electronic address: sbakhtiari2007@yahoo.com.
authors.forename: Sedigheh
authors.initials: S
authors.lastname: Bakhtiari
authors.affiliation: International Research Collaborative - Oral Health and Equity, School of Anatomy, Physiology and Human Biology, University of Western Australia, WA, Crawley, Australia.
authors.forename: Marc
authors.initials: M
authors.lastname: Tennant
authors.affiliation: International Research Collaborative - Oral Health and Equity, School of Anatomy, Physiology and Human Biology, University of Western Australia, WA, Crawley, Australia.
authors.forename: Estie
authors.initials: E
authors.lastname: Kruger
authors.affiliation: Department of Clinical Biochemistry, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Masoumeh
authors.initials: M
authors.lastname: Rajabibazl
authors.affiliation: Department of Clinical Biochemistry, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Azam
authors.initials: A
authors.lastname: Daraei
mesh_terms: D000328:Adult; D000975:Antioxidants / Q000378:metabolism*; D016022:Case-Control Studies; D006801:Humans; D008297:Male; D018384:Oxidative Stress; D012463:Saliva / Q000737:chemistry*; D012907:Smoking / Q000378:metabolism*; D013662:Tea
chemical_list: D000975:Antioxidants; D013662:Tea
keywords: Antioxidant capacity; Green tea; Saliva; Smokers