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Green tea contains nutrients and antioxidants that provide many health benefits – from preventing cancer to improving brain function. Read this article to learn all about this nutritional drink.


Tea polyphenols

Green tea contains polyphenols and catechins, which are micronutrients found naturally in our foods that can act as antioxidants.

Epigallocatechin gallate (EGCG) is the main polyphenol found in green tea and is known to have many beneficial effects on human health. The polyphenols can reduce the formation of free radicals, which play a role in diseases. This protects cells and molecules from damage. There are also minerals found in green tea that are important for health [R].

L-theanine is also found in green tea, and it is especially good for the brain.

Because there are no known health risks associated with green tea and no toxic level, green tea is a great way to help you become a healthier person [R].

EGCG Snapshot


  • Antioxidants found in green tea can help prevent cancer
  • EGCG promotes brain health and defends against Parkinson’s and Alzheimer’s Disease
  • EGCG protects the heart
  • It protects against inflammation
  • Drinking green tea can help you lose weight


  • The caffeine found in green tea can lead to anxiety, heart rate problems, etc. if you drink too much
  • It might lower testosterone levels

Health Benefits of Green Tea

1) Antioxidants Found in Green Tea Can Lower Your Cancer Risk

Green Tea Can Lower Your Cancer Risk

Oxidative damage is known to cause various cancers in the body, so the many antioxidants found in green tea help lower your risk [R].

Many studies have been done on the antioxidant properties of green tea and it has been shown that green tea lowers the risk of breast, prostate, and colon cancer in humans [R, R, R].

The polyphenols found in green tea prevents cancer from growing by regulating cancer cell growth, survival, and metastasis. It affects the cancer cells at the DNA, RNA, and protein levels [R].

2) Green Tea Promotes Brain Health

The EGCG, caffeine, and L-theanine all work to improve brain function and health.

The amount of caffeine found in green tea is enough to help improve memory and reaction time. It also increases the amount of dopamine and norepinephrine in the brain [R].  

EGCG and L-theanine both increase memory and attention in patients with mild brain damage [R].

L-theanine also has anti-anxiety effects and can help you calm down [R].

On the other hand, EGCG was proven to reduce fatigue [R].  It can refresh and relax your brain [R]. 

The polyphenols found in the brain also protects neurons and help protect against dementia, Alzheimer’s, and Parkinson’s disease [R].

Green tea also reduced depressive symptoms and increased reward learning [R].

3) Green Tea Helps You Lose Weight

Green Tea Helps You Lose Weight

Green tea can help you lose weight in many ways.

It has been shown to increase your metabolism and help burn more fat [R].

Green tea suppresses appetite and leads to less energy consumption [R].

Green tea also interacts with other compounds that burn fat as well as adrenaline to increase the body’s metabolic rate [R].

EGCG suppresses an enzyme that breaks down norepinephrine, so this increases the amount of norepinephrine in the body. This hormone signals for more fat cells to be broken down, which can now be used as energy [R].

In addition to these properties, green tea can increase your endurance. The exhaust time for patients that drink green tea was extended. This means that you can exercise for a longer time and be able to lose more weight [R]

Consumption of green tea also decreases carbohydrate consumption as well as block fat absorption [R].

In a study done on overweight and obese women, green tea consumption resulted in more weight loss [R].

4) EGCG Reduces Heart Disease Risk

Polyphenols found in green tea can reduce cholesterol, which is the main factor of heart disease [R].

Green tea also lowers blood pressure by increasing blood flow in the body [R].

5) Green Tea Lowers Risk of Diabetes

Green Tea Lowers Risk of Diabetes

Catechins in green tea can help reduce your risk for Type II Diabetes by improving insulin sensitivity [R].

This then lowers blood glucose levels [R].

6) Green Tea Fights Against Bacterial Infections

Green tea acts as an antimicrobial agent. Its properties can reduce bacteria spores in the body [R].

EGCG damages bacterial membrane and fights against infections [R]

Mouthwash with green tea in it also reduced plaque and gingivitis [R].  

7) EGCG Has Anti-Inflammatory Effects

Polyphenols found in green tea helped prevent inflammation due to UV rays [R].   

EGCG also prevents and treats inflammation due to rheumatoid arthritis [R].

8) EGCG Improves Liver Health

Polyphenols in green tea can help improve liver health. It lowers lipid levels in the body and reduces the risk for non-alcoholic fatty liver disease [R].

9) EGCG Helps Skin

EGCG Helps Skin

EGCG has anti-wrinkle effects and also reduced redness in the skin [R].

10) EGCG Prevents Baldness

EGCG helps to prevent baldness. The polyphenols in green tea can stimulate human hair growth [R].

11) EGCG Promotes Dental Health

EGCG Promotes Dental Health

EGCG helps oral defense mechanisms and can prevent gingivitis. It provides additional protection against oxidative stress in the mouth [R].

The polyphenol also helps enhance the activity of dental adhesives [R].

12) EGCG Prevents Osteoporosis

EGCG  promotes osteoclast and osteoblast growth in bone cells. EGCG can be used in stem cell research to help prevent osteoporosis [R].

13) Green Tea Can Help You Live Longer

Green Tea Can Help You Live Longer

Polyphenols in green tea protect telomeres from damage. Telomere damage can affect your biological age and increase disease risk. Thus, polyphenols can help prevent aging [R, R].

Finally, all of the benefits that green tea and EGCG offers will make your life healthier, which can also boost your longevity [R].


Green tea increases N-acetyl aspartate [R], which can help with intelligence.

Green tea may lower thyroid function [R].

Buy EGCG Supplements/ Green Tea


  • EGCG, quercetin, and carvedilol have potent antioxidant effects as evidenced by reduction of MDA contents and resumption of SOD activities. EGCG, quercetin, and carvedilol could prevent telomere attrition and telomere repeat-binding factor 2 (TRF(2)) loss remarkably, whereas captopril and losartan had no effect on oxidative stress and telomere signal [R].
  • Addition of green tea and black tea infusions (50 μl/ml) and EGCG (50 μM) to saliva, resulted in a sharp rise of OPO activity +280% (p = 0.009), 54% (p = 0.04) and 42% (p = 0.009), respectively. The elevation of OPO activity due to addition of green tea and EGCG was in a dose dependent manner: r = 0.91 (p = 0.001) and r = 0.637 (p = 0.019), respectively [R].
  • When, however, the analysis was stratified using the median of the week-0 values, the decrease at week 24 in waist circumference, systolic blood pressure, and low-density lipoprotein cholesterol in the catechin group was significantly greater than that in the control group for the above-median category [R].
  • Polyphenols up- or down-regulated activity of a number of key enzymes, including mitogen-activated protein kinases and protein kinase C, and increased or decreased protein/mRNA levels, including that of cyclins, oncogenes, and tumor suppressor genes [R].
  • EGCG with caffeine insignificantly raised EE and fat oxidation v. caffeine-only and placebo (EE 5.71 (SE 0.12) v. 5.68 (SE 0.14) v. 5.59 (SE 0.13) MJ/12.5 h, respectively; fat oxidation 84.8 (SE 5.2) v. 80.7 (SE 4.7) v. 76.8 (SE 4.0) g/12.5 h) [R].
  • LGNC-07 led to improvements in memory by marginally increasing delayed recognition in the Rey-Kim memory test (P = .0572) [R].
  • Based on a reduced proportion of body fat as estimated by bioimpedance measurement, increased liver-to-spleen CT attenuation ratio, decreased serum ALT levels and reduced urinary 8-isoprostane excretion, we concluded that 12 weeks of 700 ml per day of green tea containing >1 g catechin improved liver fat content and inflammation by reducing oxidative stress in patients with NAFLD [R].

Interactions With Other Nutrients

  • Fish Oil and Fish: Fish oil worked together with catechins in green tea to increase fat and glucose metabolism while nutrients found in fish helped lower blood pressure [R].
  • Ubiquinone: This supplement helps to increase the effectiveness of EGCG’s antioxidant properties [R].
  • Curcumin: Curcumin works together with EGCG to reduce tumor progression in colon cells [R].
  • Vitamin C: This vitamin works with green tea to reduce cancer risk [R].
  • Capsicum vanilloids: Found in hot peppers, capsicum vanilloids help fight against cancer by increasing cell killing ability [R]
  • Vitamin E: Coupled with Vitamin E, green tea polyphenols improved exercise capacity, lowered glucose levels, and reduced body weight [R].

Side Effects

If you drink too much, the caffeine found in green tea can lead to anxiety, heart rate problems, etc. L-theanine found in green tea can also cause dizziness, headaches, and digestive problems [RR].

In rats, green tea consumption lowered testosterone levels by 20% and sperm count by 2%. This might affect reproduction [R].


Do not exceed 250mg of EGCG per a day, as more has been associated with live issues.

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  • Jonathan

    This: “Green tea increases N-acetyl aspartate (R), which can help with intelligence.”
    Bogus information. The article referenced discusses green tea as a treatment for MS. The aforementioned statement suggests that “green tea makes you smarter,” which is simply not true and in no way suggested by the authors of the article. Be careful when reading about these “miracle nutriceuticals” that claim to cure/heal/benefit everything. As a scientist, I find this entire article offensive because there is no hard evidence supporting any of these claims. Many authors of articles similar to this one do not have access to scientific journals, only the abstracts. This means that they are unable to assess the integrity of the work being presented and whether it has translational value (from the research bench to medicine). Yes, some groups may have found that CELLS GROWN IN A DISH respond to green tea in a way that is beneficial, but in a live system (AKA a human or even a mouse) would not respond the same way; in fact, it might have the opposite effect due to compensatory mechanisms. While some results may be derived from humans such as bone quality in postmenopausal women drinking green tea, always remember that other factors may be at play and some individuals may drink green tea but have poor bone health. Another thing to be aware of is that consuming a green tea supplement product means a higher dose of uncharacterized compounds that is beyond what a human could possibly consume if they were just to drink green tea.

    Be skeptical. Take nothing at face value.

  • Vaidaa Alemagno

    I was told I am hypothryoid/borderline currently. I am not on synthroid though i have some extra weight on me for sure, My doctor is letting me do my thing for now with the thought that I may at some point have to get on something else, but as long as I am managing we will watch it for now and leave it alone. I have on my own and with Doctors approval decided to take kelp for several years now, which is supposed to help thyroid function. I really need to lose weight and I’m a healthy eater and low carb person, always have been, but no matter how much I work out or anything I just can’t lose anything anymore. I do not eat much either, one good meal a day, and two Healthy protein/veggie snacks a day if I’m lucky.
    So I recently bought Green Tea EGCG drops. I am reading on here it can have reverse effects on thyroid? I used to drink tons of Green Tea all on its own and I was nice and perfectly fit too. Now its just occasional.
    How mightthe EGCG effect my thyroid? Do you think its okay for me to take the drops as long as I don’t exceed. It says take 2-4 droppers per day. 2 has 250 mg of green tea and beneath that it says 125 of EGCG.

  • Dirk

    Lightly caffeinated may be more effective.

  • odell65

    I don’t agree: [huffington post]

    Friendly, Lue

  • MKW

    Does decaffeination reduce the effectiveness of green tea? I can’t tolerate even tiny amounts of caffeine, but would like to try organic decaf green tea.

  • Dirk

    Too much is anti-thyroid. It has also been proven beneficial to those with CLL.

  • Jake

    Would green tea have negative effects for someone with very little COMT?

    1. Joseph M. Cohen


      1. Alex

        But it would also potentially be extra beneficial in some other ways right?

        I read the study that showed that women with low COMT (AA) benefited more from tea consumption and had lower cancer risk.

        I understand that overdoing it can cause excess catecholamines because you hamper COMT even more, but it seems to me like low COMT individuals benefits the most from the health effects of catechins.

        Would love to hear your input Joseph!

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