Evidence based
Drinking high-quality tea is a delightful taste treat, but selecting the best teas and preparing them correctly takes knowledge and time.
If you’re mainly interested in beneficial effects of green tea like help supporting healthy blood sugar levels and healthy weight management, why not just purchase a green tea extract supplement and take one or two pills every day to save the effort?
Unfortunately, the decision isn’t quite so simple. Taking green tea extract isn’t the same as drinking green tea.
There’s some evidence in favor of the health benefits of green tea extract, but also plenty of reasons for hesitation.
Keep reading to learn all about green tea extract and EGCG, how they compare to real green tea, potentially harmful contaminants and side effects, and other helpful insights from peer-reviewed research.
What is green tea extract or EGCG?
Green tea extract is a decaffeinated mixture of polyphenols from the Camellia sinensis tea plant (the same plant from which white tea, green tea, oolong tea, and black tea are derived).
In other words, green tea extract is a concentrated version of green tea without the caffeine content. As a dietary supplement, it’s available in capsule and powder form.
Most green tea extract comes from tea leaf scraps left over from tea processing. (1) Commercial manufacturing techniques use hot water or solvents like alcohol or acetone for extraction followed by freeze-drying, spraying, or emulsification to ensure a predictable consistency. (2)
In contrast to green tea extract, epigallocatechin gallate (EGCG) is a specific, individual catechin polyphenol found in Camellia sinensis. It also occurs in lower concentrations in many fruits, in nuts, and in cocoa. (3)(4)
Green tea contains around 7.3 grams of EGCG per 100 grams of dried tea leaves. (5) It’s the most abundant catechin in tea, accounting for nearly 60% of total catechin content in green tea. (2)
Like green tea extract, EGCG is also available as a supplement and is made with a similar manufacturing process. (6) EGCG used in supplements mainly comes from leftover green tea leaves, too.
What does green tea extract do?
Because it contains many of the same compounds from Camellia sinensis, some of the properties of green tea extract are similar to the health benefits of green tea.
As we’ll discuss more below, green tea extract and green tea are not interchangeable. However, researchers often use extracts to ensure consistent results in clinical trials so they don’t introduce additional variables like different varieties of tea or steeping methods.
Similar to green tea, the extract has potent antioxidant effects and can neutralize free radicals that would otherwise cause oxidative stress and damage to cells. (7)
EGCG is the second most powerful antioxidant in tea (after epicatechin). One gram of EGCG is 50% more potent as an antioxidant than a 100-gram serving of blueberries. (8)(9)
Lastly, green tea extract also has a reputation as a fat burner.
But the evidence for the weight loss efficacy of green tea extract supplements appears to be inconsistent: while some studies have observed positive effects, a systematic review and meta-analysis from 2013 found that, overall, the evidence is inconclusive. (10)
Drinking green tea or taking green tea extract is worth a try if you have already made lifestyle changes and want extra fat burning, but you shouldn’t count on it reducing your body weight – especially if you aren’t eating a healthy diet and exercising regularly.
Is green tea extract the same as green tea?
No. Green tea extract, EGCG, and other green tea supplements are not the same as green tea.
The most apparent differences, of course, are that supplements are portable and may be more convenient, yet lack the renowned flavors and other nuances that make drinking tea a popular pastime worldwide.
And pure EGCG or epigallocatechin-3-gallate, by definition, lacks other beneficial catechins and flavonoids from green tea, like epicatechin (EC), epicatechin-3-gallate (ECG), epigallocatechin (EGC), gallic acid, and tannins. (2)
Beyond the clear-cut distinctions, though, here’s what research tells us about the tradeoffs of taking green tea extract as opposed to drinking tea.
Green Tea Extract vs. Green Tea
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- Leftover solvents including acetone, hexane, and methanol from processing are likely to be present in green tea extract unless it’s made exclusively using hot water. (2)
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- Sourcing, quality control, and contamination issues may be of greater concern with green tea extract compared to tea leaves.
The downsides of green tea extracts range from off-putting to potentially alarming, but they may not be as much of a concern if you can find a trustworthy supplier who manufactures supplements to the highest standards.
In the next section, you’ll learn whether pure green tea extract can be harmful, its potential adverse effects, and what scientific studies say about its safety overall.
Is green tea extract harmful?
Green tea extract is high in potent antioxidants like EGCG. However, powerful antioxidants in supplement form are not always good for your health.
As the authors of a 2019 paper stated, “phytochemicals from supplements (as powder, tablet, and capsule) and natural whole foods have different effects on the body, and continued consumption of supplements may also lead to negative effects.” (11)
One reason is that whole foods not only contain beneficial antioxidants, but also offer nutrients and phytochemicals that can account for advantages that exceed the benefits of supplements. (11)
According to a 2018 toxicology study of green tea and its extract, the observed safe level of daily EGCG consumption from drinking tea is 704 milligrams per day, but only 338 milligrams a day in the form of green tea extract or EGCG supplements. (12)
In other words, brewing high-quality tea appears to be a safer way to obtain large amounts of healthful tea antioxidants compared to supplements.
Beyond the downsides of consuming high doses of antioxidants in supplement form, EGCG supplements may have other associated risks, too.
Similar to many dietary supplements, EGCG could interact with some prescription drugs. Speak to a physician before taking green tea extract if you currently take drugs for heart disease, sildenafil (Viagra), blood thinners, statins, or cancer drugs. (13)
A few studies have shown signs of liver damage from green tea extract, such as elevated liver enzymes. (14) These effects are rare, and probably nothing to worry about, but you should ask your doctor or health care professional before taking green tea extract if you have liver disease or liver function issues.
Is it safe to drink green tea every day?
It’s fair to say that superior evidence exists for the health benefits and safety of drinking green tea compared to taking green tea extract.
In fact, drinking a cup of green tea or more each day is not only safe, but it’s also the best way to obtain the most health benefits from green tea.
Epidemiological studies (population data) from Asian countries where daily green tea intake is the norm suggest virtually no adverse events aside from the possibility of excessive caffeine intake, and a modestly reduced risk of various health problems. (15)
And as we discussed in the previous section, toxicology evidence suggests tea is a safer way to obtain EGCG and other green tea antioxidants than green tea extract and allows you to get over double the daily dose of green tea catechins without harm. (12)
The quality of the tea you select and the method you use to brew it also affect the safety, catechin levels, and health benefits.
Low-quality teas have a higher risk of contamination with heavy metals, pesticides, fungi, and mycotoxins. (16)(17)
Finally, one study found that mountain-grown teas from China, harvested in the spring and brewed for 5-10 minutes at 176 degrees Fahrenheit (80 degrees Celsius), had the highest overall antioxidant content. (18)
Should you prefer to avoid the possible bitterness of long steeps, steeping and re-steeping for shorter durations is another way to extract maximum levels of catechins from loose leaf tea. (18)
If you intend to drink tea daily for enjoyment or health benefits, be sure to choose high-quality teas from reputable retailers and prepare them correctly.
Final Thoughts
Green tea extract and related supplements like EGCG may be convenient, but the convenience comes with potential tradeoffs.
If you decide to purchase an extract, seek a reputable maker and ensure they use hot water extraction (and nothing else) to avoid contaminants like solvents left over from processing.
Even so, drinking real tea every day is a safer way to get higher doses of catechin antioxidants, and consumption of green tea is supported by far more health evidence than green tea extract supplementation.
