Green Tea: Antioxidant vs. Pro-Oxidant Activity
Stanila Stoeva, Nadezhda Hvarchanova, Kaloyan Georgiev, Maya Radeva–Ilieva
Abstract
Green tea is one of the most consumed beverages globally. It is very popular due to its specific taste, energizing effect and some health benefits related mainly to the catechins content. Green tea catechins possess antioxidant, anticancer, anti-inflammatory and antimicrobial activity as well as reduce body weight. One of the major and well-studied effects of green tea catechins is their antioxidant effect. However, long-term administration of high doses of antioxidants may result in a pro-oxidant effect and promote cell damage. Therefore, beneficial effects of green tea are directly related to the administered dose of catechins. But it should be noted that consumption of large quantities of green tea beverages or administration of high doses of green tea catechins does not guarantee health benefits and may even lead to adverse effects. This review provides a comprehensive overview of the current knowledge of the antioxidant and pro-oxidant activity of green tea catechins as well as research gaps that require further investigation. In conclusion, despite green tea antioxidant potential, further research is needed to fully understand the benefits and risks associated with the consumption of green tea beverages as well as green tea catechins in different forms and doses.