EGCG, Catechins and Polyphenols
in Green Tea
A FAQ Guide

Understanding the differences between EGCG, catechins and polyphenols. Which is the best way to maximize green tea's health benefits?

1. What's tea polyphenol?

When buying green tea products, knowing how to read the label is important. To decipher what the product contains, it is important to know something about green tea chemistry.

For example, let's say you come across an exciting product that says "300 milligrams of polyphenols". You may be led to believe it contains 300 milligrams of antioxidants.

You could be wrong.

Polyphenol is a much abused term. Strictly speaking, 90% of tea polyphenols are catechins, so the two terms are almost synonymous. However, for reasons I do not yet understand, this word has been used interchangeably with green tea extract.

A standardized green tea extract contains only about 30% catechins. So 300 milligrams of polyphenols may only contain 90 milligrams of antioxidants, not the 300 milligrams that you expect.

2. What are catechins?

Catechins are what make green tea special. They make up the bulk of green tea's antioxidants, and therefore its healing potential.

Catechins are unoxidized. When black tea is made, catechins oxidize to form more complex compounds called thearubigins and theaflavins. Between the two, only theaflavins contain significant antioxidant potential.

Green tea contains about 30% catechins, whereas black tea contains only 4% of theaflavins. Both are powerful antioxidants. But green tea has far more in quantity, which explains why it is associated with more health benefits.

Green Tea Catechins - Understanding Polyphenols

3. What is EGCG?

Okay, now that you understand what catechins are, the rest is easy.

Green tea contains six types of catechins: EGCG, EGC, ECG, EC, GC and C. Among the six, there is some evidence that EGCG and ECG are the most potent.

However, what makes these catechins important is not their potency, but their abundance.

About half of the catechin content of tea is EGCG. Just a small quantity of tea leaves will steep many cups of tea.

It is this relative abundance that makes green tea special. No other food or beverage contain this level of antioxidants.

EGCG is the focus of almost every scientific study, and has been associated with most of the newly discovered green tea benefits.

4. What are the health benefits?

The health benefits of this amazing antioxidant are deep and wide ranging. It literally covers every part of the body.

The Ohsaki National Health Insurance Cohort Study is one of the largest population studies ever conducted - 40,530 Japanese adults were questioned over the course of 11 years.

Researchers found those who drank 5 or more cups of green tea a day were 16% more likely to live longer than those who drank less than one cup a day.

Heavy green tea drinkers are also 26% less likely to die from heart disease.

Health Benefits - 6 Discoveries You Can't Ignore

5. Can it help me lose weight?

The weight loss effects of green tea are slow but significant, and there is real scientific evidence to justify its inclusion as one of the top ingredients in many reputable weight loss products.

It can help you lose weight safely and effectively in three ways:

  • Increase metabolism

  • Burn fat

  • Reduce fat storage

Many scientific studies have indicated that it can have some big benefits to overall health, especially because it can help you lose weight.

Weight Loss - Green Tea 3-Way Magic

6. Does it have any side effects?

Green tea has few side effects.

After all, the Chinese people have been drinking tea for thousands of years. It has been officially proven by study that green tea is the second most consumed beverage in the world after water.

It is water-soluble, which means if you overdose, it is unlikely to build up. The excess simply gets flushed out of your body.

There is only one caveat: Be careful when you are pregnant or consuming lots of sub-quality processed products (such as tea powder or dietary supplement).

Side Effects - Green Tea Extract Consumers Beware!

7. How much should I consume daily?

When considering how much to consume daily, you want to consider two things:

  • What is the manufacturer's recommendation? You don't want to exceed the maximum as it can be dangerous. For further information, read Green Tea Supplement Side Effects.

  • You don't want to consume too little, or else you will lose out on the health benefits. For information on the typical dosages used in scientific studies, read Green Tea Extract Weight Loss.

How to Maximize Benefits

8. Which foods and beverages contain the highest levels of this compound?

When choosing the healthiest tea beverage to drink, always go for the less processed option.

A 2007 report published by the US Department of Agriculture (USDA) analyzes nearly 400 foods for their EGCG content. It shows that regular green tea contains the highest concentration of antioxidants.

It is followed by decaffeinated green tea, flavored green tea and instant or bottled tea.

Tea Beverage Content - USDA Study

The same study shows why green tea is probably the best way to ingest antioxidants.

One gram of green tea steeped in 100 milliliters of water yields 127 milligrams of catechins.

In comparison, 100 grams of dark chocolate contains 54 milligrams, blueberries 52 milligrams and black grapes only 22 milligrams.

Tea Catechins - Best Food and Beverage Sources

9. How does it affect the taste of a cup of tea?

The level of EGCG present in tea leaves decreases with leaf age. Its concentration is the highest in tea buds. These tender sprouts are reserved for making the highest grade tea.

Although catechins taste astringent (the dry-mouth feeling of a banana skin), tea buds taste rich, fresh and even sweet.

Tea appreciation is an holistic experience. (Green tea contains more than 200 bioactive compounds.) High grade tea contains high levels of astringent antioxidants, and even higher levels of theanine.

The presence of EGCG by itself does not guarantee a quality cup of tea. Having too much can make a cup of tea undrinkable.

Scientists have repeatedly observed that the health benefits of tea are maximized when EGCG is acting in combination with the other tea compounds.

10. Which dietary supplement do you recommend?

While drinking a tea infusion is the tried-and-tested way for consuming green tea antioxidants, another option is to consume a dietary supplement.

The risk with dietary supplements is that quality is not uniform. High degrees of processing, together with the lack of scientific testing and FDA regulation, means plenty of sub-standard products exist.

Contrary to what many manufacturers claim, one capsule of extract does not equal many cups of tea. Such product claims are usually based on the lowest grade tea leaves.

If you are drinking a quality tea, you can consume enough antioxidants to satisfy your daily needs.

So your best bet is to seek out a high quality tea, such as the Dragonwell or Biluochun available from the Tea Shop. Alternatively, Teavigo is a good choice if you want a quality decaffeinated option.

EGCG Green Tea Extract - Buyer's Guide

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Harold N, Graham PD (1992). Green tea composition, consumption and polyphenol chemistry. Journal of preventive medicine and hygiene. 1992 May;21(3):334-50.

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