Tea has a uniquely high content of flavonoids.
What is the significance of this statement?
To begin with, let’s take a quick look at what free radicals (FR) and reactive oxygen species (ROS) are. FR and ROS are both unstable molecules that can be damaging when found within the body. They may either be produced naturally – as a by-product of cellular metabolism such as cell respiration, or might enter the body via air pollutants, toxins in food, tobacco smoke, exposure to ionising radiation or heavy metals, etc.
Unstable FR and ROS molecules react with stable molecules in the body to stabilise themselves, in turn making the previously stable molecules unstable. The process then continues in a sort of chain reaction. A build-up of FR and ROS could put the body in a state of ‘oxidative stress’ which, over time, could lead to the development of non-communicative diseases (NCDs) such as cancer, stroke and heart disease.
Flavonoids function as antioxidants, neutralising unstable FR and ROS molecules and subsequently reducing prolonged oxidative stress and lowering the risk of developing NCDs. This is where the statement ‘Tea has a uniquely high content of flavonoids’ bears significance.
The tender shoots of the tea plant are packed with two main types of flavonoids – flavanols (18-32%) and flavonols (3-4%). While the tea manufacturing processes vary for black, green and oolong teas, the flavonoid content in the end products remains significantly higher than in any other food, giving rise to a high antioxidant capacity. Thus, regular consumption of high-quality tea can boost antioxidant activity within the body, helping to improve overall health and reduce the risk of developing NCDs.
Comparison of Antioxidant capacity of tea and common vegetables – Figure 4.1 from page 52 of Tea and Your Health by Prof. Tissa Amarakoon
