Research & News RoundUp – January 2025
Green tea is a known superfood, primarily for its EGCG content. But did you know that there is huge variation between the content of EGCG in different brands of green tea? That how you prepare and drink the tea can significantly change how much EGCG it imparts? And that your microbiome also influences how beneficial the EGCG effects are?
EGCG supplements are a useful tool in functional medicine, packing a powerful punch that can enhance a patient’s therapeutic program. However, we can all reap the benefits of EGCG by consuming dietary sources.
What’s the big deal with EGCG?
EGCG, which stands for epigallocatechin gallate, is a polyphenol (read “amazing plant compound”) with potent health protective effects against the following diseases and more:
It is also a powerful adaptogenic modulator of our epigenetics, which regulate how our genes are expressed.
How to brew a tea that is higher in EGCG
Brewed tea contains the highest concentration of EGCG, and its concentration increases with brewing time.
To maximize EGCG content, pour boiling water (not just hot water) over a green tea bag and let steep for 10 minutes before removing the bag and drinking.
The only trade off with increased brewing time is a slight increase in bitterness. If you want to counteract this, try a little bit of lemon juice or sliced lemon, or add a lemon verbena tea bag while brewing.
Choosing the right brand of green tea
Teavana Green Tea Gyokuro has been found to have the most EGCG but is also one of the most expensive brands.
Amongst other, more readily available brands, Celestial Seasoning and Lipton green tea beat Bigelow and Stash brands.
Decaf, pre-mixed green teas, or flavored green teas contain much less EGCG than freshly-brewed tea, and may also have undesirable extra ingredients.
Organic teas are also a good choice, with good brands being Choice or Traditional Medicinals.
When to consume green tea
EGCG, like other catechins, binds to proteins in our food to form complexes that are less absorbable into our bloodstream. Therefore, to reap the most benefit from green tea, it’s best to consume between meals rather than directly with food.
EGCG can also bind with minerals in our food such as iron reducing its absorption too—yet another reason to drink your green tea separately from other foods.
Will my green tea keep me up at night?
Green tea contains much less caffeine than black tea or coffee. However, it does still contain some caffeine, so if you’re sensitive you may want to limit your consumption to the morning hours. Big bonus, though—if you’re looking to cut back on your caffeine consumption, green tea is a nice alternative that still packs a little caffeine punch.
Here’s how the caffeine content of green tea compares with alternatives:
| Beverage | Caffeine per 8 oz cup |
| Green tea | 35-70 mg |
| Black tea | 60-90 mg |
| Coffee | 150-200 mg |
Alternative sources of EGCG
Did you know that green tea is not the only source of EGCG? While green tea is relatively more potent, you can also find a reasonable amount of EGCG in white tea and oolong tea.
Some other foods such as strawberries, raspberries, blackberries, plums, peaches, kiwi, and avocado also contain small amounts of EGCG.
How does this connect with my microbiome?
A healthy microbiome is likely essential for optimizing the benefits of all dietary polyphenols including EGCG. These gut organisms are known to convert polyphenols into many different derivatives that have altered absorption properties and activities in the body.
Summary: top 3 tips for maximizing EGCG benefits:
- Choose brewed green, oolong or white tea and steep for 10 minutes
- Consume away from other meals
- Keep your microbiome healthy with a diet rich in plant foods, avoiding processed and sugary foods
If you find you can’t manage to get a regular intake of green tea, a supplement can help fill that gap! You can find my favorite EGCG supplements below. – DrKF
18 Comments
No doubt Green tea have many positive effects on our health…thanks for writing this informative blog so that people can know about tea more and more.
I enjoyed this information but don’t know what I should do. I am very sensitive to caffeine so usually have decaf tea- green and other types. I try not to have strong tea if it isn’t decaf- but dilute it to prevent the shakiness that can occur.
As for berries, because of diverticulosis, I was told years ago, to avoid berries except for blueberries. This was after freeze-dried strawberries caused a severe attack of diverticulitis, with resulting peritonitis, that almost killed me. After having a colostomy and three months later, rejoining of the colon, I had to be careful what I ate.
Is drinking decaf tea better than drinking no tea? What do you suggest I do? I have Hashimoto’s also so it is a problem, as it is, trying to do what is best for my gut. I find different functional medical doctors and pharmacists differ in what they tell the patients. I am getting very frustrated by what I read is best for us all! Your advice? Thank You!
Joan
It sure sounds frustrating! I think avoiding caffeine is important, and sounds like you need to be cautious what you consume regularly. Luckily there’s loads of naturally caffeine-free herbal teas with wonderful antioxidant and other medicinal activity. Brewing teas with turmeric, ginger, rosemary, mint, sage, thyme as well as floral herbs like chamomile, lavender, white teas and the like can be a wonderful and therapeutic alternative. However, only use the herbs you are able to tolerate and follow the advice of your physician.
Great reminder on green tea. I’ve tried green tea in bags at the store didn’t like the taste, it just sat and then was eventually tossed. If your trying to get into green tea but not liking it, buy it loose and brew your own with tea balls, buy small amounts until you find one you like. Once your drinking green tea regularly you’ll start to notice the feel good aspect of it more. I think when you make a change, especially to eating or drinking something that is beneficial you that sometimes can get a little bit of a detox or herx reaction, don’t let that dissuade you. You could easily get hooked on the caffeine aspect of tea itself. I absolutely love jasmine pearl tea, it’s a little pricey but cheaper than buying lets say sodas or coffees; You can re-steap jasmine pearl. The average around the world for drinking green tea daily is about three cups. Do not be afraid to try different teas, their are some hidden gems of flavor out there to find.
I’ve heard that if green tea is brewed above 170 degrees farenheit that it will destroy the antioxidants. Is this true? And, if so, are you still recommending boiling water instead of 170 degree water because EGCGs are better than antioxidants? Thanks!
There are some studies that suggest that brewing tea over 200 degrees Fahrenheit may cause some degradation of the polyphenol activity, but I think it’s safe to say that at usual brewing temperature of ~ 170-190 deg Fahrenheit you’re getting good benefit from antioxidant activity. Other factors may also come into play, like freshness and pH which may affect antioxidant activity. Enjoy!
Thank you for the simple brewing instructions. Who would have imagined that the best sources are green teas so easily found at the average grocery store! This was extremely helpful. Thank you!
You’re welcome!
If you want to try Japanese green teas, nioteas.com has some really good ones, a little bit more expensive but worth it
Okay, I just read the consumerlab report referenced in the nytimes article and it does confirm that powdered Matcha tea contains hundreds of times more EGCG than leafy tea. Personally however, I would only trust a Japanese Matcha that is grown and harvested under strict Japanese regulation.
Wouldn’t the matcha type of green tea be a far more potent source of the EGCG?
Studies have shown that matcha might have up to 3 times the amount of EGCG as green tea leaves. Both are great sources, and consistent intake of both has been shown to be beneficial – plus not everyone tolerates the more potent flavor of matcha.
Hi does drinking it cold reduce the benefits? Thanks Angie
Hi Angie, there’s no data on this specifically but we would assume that you would get the same benefit if you allowed it to cool as drinking it warm. There may be a possible degradation over time, say if you were drinking it a day or two later. – Team DrKF
Thank you for all your work to help I form the public:)
This study may be if interest to you:
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4573099/
The results show that the maximum amount of EGCG is extracted at 3 minutes in water at 85 degrees and then the concentration declines with further steeping time (or at higher temperatures – they also tested 95 degrees).
Hi Monique, I just read the site you posted. It does look like they recommend the 3-4 minute brewing time, however the 85 degrees is celsius, which would make the water 185 degrees fahrenheit.