Evidence-based research on the nutritional and health effects of functional components of tea

As a traditional nutritional and healthy cash crop in China, tea has certain significance in promoting human health and preventing and controlling chronic diseases. Studies have shown that the nutritional health effect of tea is due to its rich functional components, mainly including tea polyphenols, tea pigments, tea polysaccharides, theanine, alkaloids and other bioactive substances. At present, researchers from the academic circles have continuously carried out animal and human experiments on the health effects of various functional components of tea, which has accumulated abundant research data and materials. Based on this, this article reviews the literature on the nutritional and health effects of the main functional components of tea, and adopts the method of evidence-based research to screen and extract relevant data for qualitative and quantitative meta-analysis. Subsequently, the nutritional health effects of the five functional components of tea, namely tea polyphenols, tea pigments, tea polysaccharides, theanine, and alkaloids, are summarized and outlined. Studies have shown that tea polyphenols, tea pigments, tea polysaccharides, theanine and alkaloids have different health effects and are expected to play their unique roles in promoting human health and preventing and controlling diseases.