Green and White Tea: 1 out of 100 reasons it’s good for you.

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.

Drink up!

Some of my stash

Some of my stash!


Impaired Metabolic Flexibility, what it means and could it be at the root of your health issue(s)?

Burning Fuel: Car vs. Human

Our body is often compared to a car or a machine.  We hear things like “Your tank is on empty and you have no energy until you refuel” or “ensure your tank/battery never runs empty”.  What is our tank?  Our battery?  Is it our stomach?  Some other body part?  Could it be much more complex?  What is actually happening, when we “fill our tank” and can we “run empty” if we skip a meal or a snack?

A Primer: Cellular Respiration, Glycolysis and Beta-Oxidation

Cellular respiration is what takes place in the cells to convert energy from nutrients (what we eat) into usable metabolic energy (ATP).  The two main types of cellular respiration are anaerobic (without oxygen) and aerobic (with oxygen).

Anaerobic metabolism, think sprinting or lifting heavy weights, is glucose based and can only be maintained for short periods.

Most of our life is spent in an aerobic metabolism. Our two primary aerobic sources of energy are glycolysis, which uses glucose, and beta-oxidation, which uses fat.  Our cells ability to effectively switch from a primary fat metabolism to a glucose metabolism and back to burning fat is called metabolic flexibility.

Metabolic flexibility varies considerably from individual to individual.

Insulin, the fuel selector

All food intake result in the release of the hormone insulin by the pancreas.  When insulin is high (after food consumption), the body shifts towards burning excess glucose and storage of nutrients.  When levels of insulin are low (between meals and in fasting condition), the body burns mostly fat.

Genetic predisposition and long-term exposure of our cells to high level of insulin could be major contributing factors in the development of a condition called insulin resistance, where cells fail to respond to a normal amount of insulin.  It is very similar to our body adapting to loud music during live rock music concert by tuning down our hearing.

The pancreas tries to keep up with the increased demand for insulin by producing more.  Excess glucose accumulates resulting in high levels of both glucose and insulin in the blood at the same time, which impairs the body’s ability to switch back to burning fat for fuel.  This vicious cycle often result in hunger and fatigue/lethargy because our body thinks it’s starving.  There is an issue in communication and fuel utilization.

If our ability to switch from burning glucose to burning fat after a meal is impaired, we’ll become excessively hungry no matter how much stored fat we have available to burn.

If we were a hybrid car, it would be the equivalent of going from our primary electric fuel to gas, for a moment, but not being able to switch back to electric.  Our need for gas would be dramatically increase even if the car batteries are fully charged.

How does this affect our health?

The scientific literature states that an impaired cellular ability to increase fatty acid oxidation precedes the development of insulin resistance in genetically susceptible individuals.  This is important because we can relate impaired fat oxidation to the causes, not the consequences of metabolic syndrome, obesity, diabetes and the list is long.

So we could state that genetics (impaired fatty acid oxidation) + environment (exposure to high level of insulin leading to developing insulin resistance) = health issues linked to metabolic disorders.

As an example: I have a genetically impaired fatty acid oxidation i.e. several family members have insulin resistance related health issues.  I was bottle fed, raised a vegetarian and consumed the majority of my calories in the form of very insulinogenic food such as grains, starches and fruits.  I was constantly hungry and consuming a lot of food but being still young and not as metabolically damage, I had energy and was thin.  Within one to two hours after a meal I was already back in the fridge and pantry looking frantically for more food (symptom of low blood sugar/cells having a hard time switching back to burning fat).  As a teenager, I developed Polycystic Ovarian Syndrome (linked to insulin resistance) and a rapid and stubborn weight gain.

In practical term there is two main ways to deal with the issue and the hunger (I’ll elaborate in a subsequent post):

  • Eating several small lower-insulinogenic meals and snacks thought out the day, keeping our body mostly in glycolysis.  Hunger is managed by frequent feeding.
  • Depriving our body of excess dietary glucose in order to facilitate the adaptation of using fat as the main fuel.  With time, hunger will almost disappear