Does green tea consumption improve the salivary antioxidant status of smokers?

•Alteration in salivary antioxidant status after green tea drinking is proposed.•Difference in smoker and non-smokers antioxidant level after green tea consumption is indicated.•Time-relation between green tea consumption and salivary antioxidants enhancement is concluded.

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 (7 days) and long-term (3 weeks), green tea drinking.DesignIn 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 2 g of green tea in 150 ml of hot water for each cup. After saliva collection, antioxidant capacity of saliva was measured at baseline, after 7 days, and after 21 days. 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/50 μl, 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.ConclusionsResults support the effectiveness of green tea consumption in salivary antioxidants enhancement in smokers, in both the short- and long term.