A recent literature search revealed no fewer than 8,000 citations relating to green tea's chemistry, bioactivity, production and potential health benefits.
Effects of Green Tea in oxidative stress and cardiac health Tea, especially green tea, is an important source of polyphenols, which act as strong antioxidants by scavenging reactive oxygen and nitrogen species and by chelating redox-active transition metal ions. Green tea's beneficial effects are attributed to its ability to reduce oxidative stress, lipid peroxidation, free radical generation and unhealthy LDL cholesterol-oxidation. There is also suggestive evidence that green tea catechins have a role in the protection against degenerative disorders.
Several oxidative stress conditions such as highly competitive physical exercise or pregnancy result in an increase of membrane-bound haemoglobin (MBH) due to the degradation of red blood cell metabolism and of the antioxidant defenses in aged and damaged red blood cells. A clinical study found that drinking green tea corresponds to a significant decease in MBH, suggesting a reduced oxidative stress within red blood cells.
Experimentally, some catechins have also been shown to inhibit a key enzyme (squalene epoxidase) in the pathway of cholesterol biosynthesis. The potent antioxidant properties of tea polyphenols reduce free radical damage to cells and prevent the oxidation of LDL cholesterol.
Green Tea for Immune Health There is evidence to suggest green tea may be beneficial in supporting immune health. Several in vitro studies found tea polyphenols inhibit a vast array of clinically relevant molecular targets and cellular processes such as antiapoptotic Bcl-2 proteins, and vascular endothelial growth factor receptor (VEGFR) signaling. There is further support by animal studies suggesting the consumption of green tea or green tea supplements with high levels of tea polyphenols may have a significant effect on the prevention of abnormal cell growth.
The health benefits of green tea are based on tradition or scientific theories. A number of pharmacological studies have demonstrated that the unique set of catechins in green tea possesses various biological activities in human body, such as antioxidant, immune system and cardiovascular system, which can potentially interfere with many disease-related biochemical processes. Green tea is a freely available phenomenal medicinal herb without a prescription and horrendous negative side effects. Hence, many people are turning to green tea to enhance their health and protect against chronic diseases.
This article includes excerpts from the original article by Shennong.