Green Tea Consumption after Intense Taekwondo Training Enhances Salivary Defense Factors and Antibacterial Capacity

The aim of this study was to investigate the short-term effects of green tea consumption on selected salivary defense proteins, antibacterial capacity and anti-oxidation activity in taekwondo (TKD) athletes, following intensive training. Twenty-two TKD athletes performed a 2-hr TKD training session. After training, participants ingested green tea (T, caffeine 6 mg/kg and catechins 22 mg/kg) or an equal volume of water (W). Saliva samples were collected at three time points: before training (BT-T; BT-W), immediately after training (AT-T; AT-W), and 30 min after drinking green tea or water (Rec-T; Rec-W). Salivary total protein, immunoglobulin A (SIgA), lactoferrin, a-amylase activity, free radical scavenger activity (FRSA) and antibacterial capacity were measured. Salivary total protein, lactoferrin, SIgA concentrations and a-amylase activity increased significantly immediately after intensive TKD training. After tea drinking and 30 min rest, a-amylase activity and the ratio of a-amylase to total protein were significantly higher than before and after training. In addition, salivary antibacterial capacity was not affected by intense training, but green tea consumption after training enhanced salivary antibacterial capacity. Additionally, we observed that salivary FRSA was markedly suppressed immediately after training and quickly returned to pre-exercise values, regardless of which fluid was consumed. Our results show that green tea consumption significantly enhances the activity of a-amylase and salivary antibacterial capacity.