Tea, the leaves of the plant Camellia sinensis, has shown beneficial health effects in the prevention of cancer, obesity, diabetes, neurodegeneration and cardiovascular diseases (CVDs) in many laboratory and different human studies (Yang et al. Ann. Rev. Nutr. 2013;33:161-81). Whereas solid data have been obtained in laboratory studies, significant beneficial effects have been observed only in some epidemiological studies and intervention trials. In large cohort studies in China and Japan, tea consumption has been associated with lower risk of total deaths from all causes, as well as with incidence and mortality of CVDs. However, reduction of incidences and mortality of cancer were observed in some, but not other studies. Many of these activities have been attributed to the actions of tea polyphenols (catechins) and some activities to caffeine and theanine. For the prevention of obesity and diabetes, two types of mechanisms of action have been extensively investigated: 1) In the gastrointestinal tract, tea catechins decrease the digestion and absorption of macronutrients and may modulate gut microbiota; and 2) after systemic absorption, catechins decrease the synthesis of glucose and fatty acids and increase the catabolism of fat and carbohydrates coordinately, through the actions of metabolic regulators such as AMPK (Yang et al. Mol. Nutr. Food Res. 2016;60:160-74). These actions would also contribute to the prevention of cancer and CVDs. In addition, antioxidant activity and different cancer and CVDs specific protective mechanisms have been proposed. Many human trials have shown beneficial effects of tea catechins only at doses equivalent to 3-4 cups of tea (or 600-900 mg catechins) per day or higher doses. However, large doses of tea extracts in tablet form may increase the risk of liver toxicity. The optimal quantity of tea consumption and their effects on different aspects of human health need to be further investigated.

Studies on prevention of obesity, diabetes, cardiovascular diseases and cancer by tea

256th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.