Relation of tea ingestion to salivary redox and flow rate in healthy subjects

The biochemistry of human saliva can be altered by food intake. The benefits of tea drinking were extensively studied but the influence of tea ingestion on human saliva has not been revealed. The work aimed to investigate the immediate and delayed effect of vine tea, oolong tea and black tea intake on certain salivary biochemistry and flow rate. The saliva samples of healthy subjects were collected before, after and 30 min after tea ingestion. The chemical compositions and antioxidant capacity of tea samples were analyzed to correlate with salivary parameters. Principal component analysis indicated that the effects of vine tea consumption were dominated by increasing salivary flow rate (SFR), production rate of total protein (TPC), thiol (SH), malondialdehyde, catalase activity and antioxidant capacity (FRAP) in saliva. The antioxidant profle of studied tea samples (FRAP, polyphenols, flavonoids) was positively correlated with salivary SFR, TPC, SH and FRAP but negatively correlated with salivary uric acid concentration in saliva.(c) 2023 Beijing Academy of Food Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

The biochemistry of human saliva can be influenced by food intake. Although the benefits of tea drinking have been extensively studied, its impact on human saliva remains unknown. This study aimed to investigate the immediate and delayed effects of vine tea, oolong tea, and black tea ingestion on salivary biochemistry and flow rate. The results showed that vine tea consumption increased salivary flow rate, total protein production, thiol levels, malondialdehyde concentration, catalase activity, and antioxidant capacity in saliva. The antioxidant profile of the studied tea samples was positively correlated with salivary flow rate, total protein production, thiol levels, and antioxidant capacity, but negatively correlated with salivary uric acid concentration.