Green tea is one of the most commonly consumed teas in the world.
Green tea extract is its concentrated form, with just one capsule containing the same amount of active ingredients as an average cup of green tea.
Like green tea, green tea extract is an excellent source of antioxidants. These have been credited with various health benefits — from promoting heart, liver, and brain health to improving skin and even reducing cancer risk.
Moreover, many studies have looked at the ability of green tea extract to aid weight loss. Many weight loss products list it as a critical ingredient.
Despite these benefits, it’s essential to know that green tea extract can also be toxic when taken in excess, so always talk with a health professional if you’re interested in taking these supplements.
This article explores ten science-based benefits of green tea extract.
1. Green tea extract is high in antioxidants
The health benefits of green tea extract are primarily due to its high antioxidant content.
Antioxidants can help reduce oxidative stress in your body by fighting cell damage caused by molecules called free radicals. This cell damage is associated with aging and several diseases.
Polyphenol antioxidants called catechins make up most of green tea extract’s antioxidant content. Among the catechins in green tea, epigallocatechin gallate (EGCG) is the most researched and thought to provide the most health benefits.
Studies have shown that green tea extract increases your body’s antioxidant capacity (the activity of your body’s own antioxidant enzymes) and protects against oxidative stress. This, in turn, may prevent associated health concerns.
For example, in one 2012 study, 35 people with obesity took 870 mg of green tea extract for 8 weeks. Their blood antioxidant capacity increased from 1.2 to 2.5 μmol/L, on average.
It should be noted that the participants in this small study were taking green tea extract in an amount considered toxic. Because of this, it’s unclear whether green tea extract would have the same effect if taken in smaller, safer doses.
Summary: Green tea extract is rich in antioxidants called catechins, which have been shown to increase antioxidant capacity and protect against oxidative stress.
2. Green tea extract may promote heart health
Oxidative stress increases fat buildup in your blood, which promotes inflammation in your arteries and leads to high blood pressure.
The antioxidants in green tea extract can decrease inflammation and help reduce blood pressure. They can also inhibit fat absorption in cells, helping reduce blood fat levels.
In one 2012 study, 56 people with obesity and high blood pressure took 379 mg of green tea extract daily for three months. They showed a significant decrease in blood pressure compared with the placebo group.
Additionally, they experienced significant reductions in blood fat levels, including lower triglycerides and both total and LDL (bad) cholesterol.
An older study in 33 people with no underlying health conditions found that taking 250 mg of green tea extract daily for eight weeks reduced total cholesterol by 3.9% and LDL (bad) cholesterol by 4.5%.
Since high blood pressure and high blood fat levels are risk factors for heart diseases, regulating them can promote heart health.
Summary: The catechins in green tea may help reduce blood pressure and improve blood fat levels, which promotes heart health.
3. Green tea extract is good for the brain
The antioxidants in green tea extract, especially EGCG, have been shown to protect brain cells from oxidative stress.
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This protection can help reduce brain damage that could lead to mental decline and brain diseases like Parkinson’s, Alzheimer’s, and dementia.
Green tea extract can also decrease the action of heavy metals like iron and copper, both of which can damage brain cells.
It’s also been shown to help memory by enhancing the connection between different parts of your brain.
In a 2014 study, 12 people drank a soft drink containing either 27.5 grams of green tea extract or a placebo. Then, while the participants worked on memory tests, brain images were obtained to assess brain function.
The green tea extract group showed increased brain function and task performance compared to the placebo group.
Summary: Green tea extract has been shown to affect brain health and memory positively and may help protect against brain diseases.
4. Green tea extract can help with weight loss
Green tea extract is rich in catechins and contains a decent amount of caffeine. Interestingly, this combination of ingredients is responsible for green tea extract’s modest weight loss properties.
Both catechins and caffeine have been shown to assist in weight loss by regulating the hormones that can enhance thermogenesis. Thermogenesis is the process by which your body burns calories to digest food and produce heat.
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Green tea has been shown to boost this process by making your body more effective at burning calories, leading to weight loss.
In one older study, 14 people took a capsule containing a mixture of caffeine, EGCG from green tea, and guarana extract before each meal. It then examined the effect on calorie burning and found that the participants burned 179 more calories, on average, in the following 24 hours.
However, the results are mixed.
In another well-designed study, 60 adults took 56 mg of green tea extract and either 28 to 45 mg of caffeine or a placebo daily for 12 weeks. This study found no significant effect on resting energy expenditure or body composition.
And, since caffeine is known to stimulate energy expenditure, the modest weight loss effects of green tea extract may be due — at least in part — to the caffeine itself.
One study determined that green tea catechins don’t significantly affect energy expenditure when tested against caffeine alone.
Plus, the amount of caffeine you consume may affect your body’s response to green tea extract.
Those who regularly consume high amounts of caffeine (greater than 300 mg per day, or about 3 cups of coffee) may not experience as significant an effect from green tea extract.
In one 12-week study, 115 women with overweight took 856 mg of green tea extract or placebo daily. While those taking the green tea extract lost 2.4 pounds on average, people taking a placebo lost more weight and experienced a greater decrease in waist and hip circumference.
It should be noted that the dosage of green tea extract used in this study is in the toxic range for daily catechin intake. People taking high doses of green tea catechins should monitor their liver enzymes to avoid liver damage or acute liver failure.
While a cup of green tea contains 50 to 100 mg of green tea catechins and 30 to 40 mg of caffeine, studies of green tea extract often contain 375 mg or more of green tea catechins and up to 600 mg of caffeine.
Those sensitive to caffeine or cardiovascular issues should consider this before taking green tea extract for weight loss. It’s always good to speak with a healthcare professional so they can help you decide whether green tea extract is suitable for you.
Summary: Green tea extract may aid weight loss by increasing the calories your body burns through thermogenesis; however, the effect is modest, and it’s unclear whether green tea catechins or caffeine are responsible. High doses of green tea extract are toxic and may lead to severe liver damage.
5. Green tea extract might benefit liver function
The catechins in green tea extract may also help reduce inflammation caused by some liver diseases, such as nonalcoholic fatty liver disease (NAFLD).
One study gave 80 participants with NAFLD either 500 mg of green tea extract or a placebo daily for 90 days.
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The green tea extract group showed significant reductions in liver enzyme levels, indicating improved liver health.
Similarly, 17 patients with NAFLD took 700 ml of green tea, which contained at least 1 gram of catechins, daily for 12 weeks. They significantly decreased liver fat content, inflammation, and oxidative stress.
However, as mentioned above, it’s essential to have your liver functions tested regularly because excessive amounts of green tea catechins are harmful to the liver. Talk with a healthcare professional to determine the proper dosage for you.
Summary: Green tea extract seems to help improve liver function by decreasing inflammation and oxidative stress.
6. Green tea extract may reduce the risk of cancer
Maintaining your body’s tissues and organs are characterized by cell death and regrowth. Specialized cells known as stem cells produce new cells to replace those that die. This process keeps cells active and healthy.
When this balance is disrupted, cancer can occur. This is when your body starts producing dysfunctional cells, and cells don’t die when they should.
The antioxidants in green tea extract, especially EGCG, seem to favor the balance of cell production and death.
One small older study explored the effects of taking 600 mg of green tea catechins daily for a year on men at risk of developing prostate cancer.
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It found that the likelihood of developing cancer was 3% for the green tea group, compared with 30% for the control group.
Summary: Green tea extract has been shown to help maintain cell health. It may even help prevent some types of cancer, though more research is needed.
7. Green tea extract may be good for the skin
Whether taken as a supplement or applied to the skin, green tea extract has improved skin health.
An extensive review demonstrated that when applied to the skin, green tea extract can help treat a variety of skin concerns, such as dermatitis, rosacea, and warts. It has been shown to help with skin aging and acne as a supplement.
For example, a study showed that consuming 1,500 mg of green tea extract daily for four weeks significantly reduced red skin bumps caused by acne.
Moreover, both supplements and the topical application of green tea extract seem to help prevent skin conditions like loss of skin elasticity, inflammation, premature aging, and cancer caused by exposure to UV rays.
A study of 10 people revealed that applying a cream containing green tea extract to the skin for 60 days improved skin elasticity.
Additionally, a study showed that applying green tea extract to the skin reduced skin damage caused by sun exposure.
Interestingly, adding green tea extract to cosmetic products has been shown to benefit the skin by providing a moisturizing effect.
Summary: Green tea extract has been shown to help prevent and treat several skin conditions.
8. Green tea extract may benefit exercise performance and recovery
Green tea extract seems helpful in exercise, improving exercise performance or enhancing recovery.
While exercise has many health benefits, it’s known to produce oxidative stress and damage cells in the body. Antioxidants, like green tea catechins, can reduce cellular damage and delay muscle fatigue.
A study in 35 men showed that green tea extract combined with strength training for four weeks enhanced the body’s antioxidant protection.
Additionally, 16 sprinters who took green tea extract for four weeks demonstrated increased protection against oxidative stress produced by repeated sprint bouts.
Green tea extract also seems to benefit exercise performance.
One study found that 14 men who consumed green tea extract for four weeks increased their running distance by 10.9%.
Summary: Green tea extract increases antioxidant protection against oxidative damage caused by exercise. This translates to better exercise performance and recovery.
9. Green tea extract may help lower blood sugar
The catechins in green tea, especially EGCG, have been shown to enhance insulin sensitivity and regulate blood sugar production, both of which can lower blood sugar levels.
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A study gave 14 people with no underlying health conditions a sugary substance and either 1.5 grams of green tea or a placebo. The green tea group experienced better blood sugar tolerance after 30 minutes and showed better results than the placebo group.
Another study showed that green tea extract improved insulin sensitivity in healthy young men by 13%.
Remember that these studies were very small, and the participants had no underlying health conditions. Many people with diabetes, on the other hand, take medications that affect their liver, and many have NAFLD, so they would need to monitor their liver enzymes.
If you have diabetes, you should speak to your doctor before taking these supplements.
17 studies concluded that green tea extract helps decrease fasting blood sugar levels. It can also help lower levels of hemoglobin A1C, which is an indicator of blood sugar levels over the past 2–3 months.
Summary: Green tea extract has been shown to increase insulin sensitivity and blood sugar tolerance, all while decreasing hemoglobin A1C and blood sugar levels.
10. Green tea extract is easy to add to your diet
Green tea extract is available in liquid, powder, and capsule forms. A wide selection can be found on Amazon.
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The liquid extract can be diluted in water, while the powder can be mixed into smoothies. However, it has a strong taste.
The recommended dosage of green tea extract is between 250–500 mg daily. This amount can be obtained from 3–5 cups of green tea or about 1.2 liters.
But it’s important to know that not all green tea extract supplements are created equal. Some supplements contain only dry green tea leaves, while others contain isolated forms of one or more catechins.
Because the FDA does not regulate supplements to ensure safety, purity, or verification of contents, you should only purchase supplements that an independent lab has analyzed to verify purity and content.
The catechin most closely linked to the health benefits of green tea extract is EGCG, so you’ll want to ensure that the supplement you are consuming contains it.
Finally, it’s best to take green tea extract with foods. Exceeding the recommended dose and taking it on an empty stomach may cause severe liver damage.
Summary: Green tea extract can be consumed in capsule, liquid, or powder form. The recommended dose is 250–500 mg, taken with food.
Green tea extract has been shown to help improve health and body composition thanks to its high antioxidant content.
Many studies have shown that green tea extract can promote weight loss, blood sugar regulation, disease prevention, and exercise recovery.
It can also help keep your skin and liver healthy, reduce blood fat levels, regulate blood pressure, and improve brain health.
It can be consumed in capsule, liquid, or powder form. The recommended dose is 250–500 mg daily, and it’s best taken with food. Amounts above this may be toxic. Plus, people with diabetes or those taking certain medications should speak with a healthcare professional before taking any amount of green tea extract.
Whether you want to improve your general health or decrease your risk of disease, green tea extract is an easy way to add health-boosting antioxidants to your diet.