The Chinese have known about the medicinal benefits of green tea since ancient times. Some state that green tea has been used as a medicine in China for at least 4,000 years.
Today, scientific research is providing convincing evidence on the benefits of drinking green tea notably for cancer, rheumatoid arthritis, high cholesterol levels, cardiovascular disease, infection and impaired immune function.
We know it is good for us, but we might not know why. We heard about epigallocatechin-3-gallate (EGCG) and catecholamines and that it boost our metabolism and mood. We’ll explore an important mechanism of action in the following and see why our health could benefit from it.
The active component we’ll discuss is the catechin EGCG and its effect on our metabolism and brain, particularly on our Sympathetic Nervous System which control the fight-or-flight response.
Our SNS produces several important catecholamines one of them called norepinephrine, is our primary fat burning signaling hormone. A higher level of catecholamines is associated with increase fat oxidation, lean tissue retention, greater energy, lower hunger, as well as improvement in glucose and insulin utilization (improve metabolic flexibility/insulin sensitivity).
In brief, it makes our metabolism much more efficient, especially for those of us who have damages that originate from our genes, environment or are self induce like excessive dieting.
The polyphenols in green tea boost another important catecholamine called dopamine. Dopamine is a signaling substance that is crucial to create a positive mood state.
What we want is to elevate catecholamines/norepinephrine levels and extend its metabolic action.
The role of EGCG is that it inhibits an enzyme called catechol-O-methyltranferase, or COMT. COMT is antagonistic to norepinephrine and will degrade it. EGCG being abundant in green and white tea, will help inactivate a lot of COMT, skewing the ratio in favor of norepinephrine, dopamine and other catecholamines.
White Tea vs. Green Tea
It is important to realize that they both come from the same plant, Camellia sinensis. The main difference between the two, is that white tea comes from the young buds and leaves and is not treated, while green tea is made from slightly more mature leaves and is lightly fermented. White tea contains a higher percentage of EGCG and other catechins, but most studies on their health benefits have been done using green tea. I tend to have a slight bias towards white tea but it’s not as readily available. I personally drink both.
The effect of EGCG is dose dependent. Higher intake leads to more benefits.
Lucky for us, good quality green and white tea is readily available. Don’t shy away from all the new yummy flavors, warm or iced. A little lemon juice (vitamin C) has been show to boost the power of the catechins. Milk or cream does the opposite. Never make green or white tea with boiling water, it will develop a bitter taste. I don’t use sugar or artificial sweetener.