HomeHealth articlesgreen teaGreen Tea And Its Health Benefits

Green tea has various health benefits, such as memory improvement, lowering the risk of cancer, and weight reduction. Read the article to learn more.

Written by

Dr. Divya Banu M

Medically reviewed by

Sanchari Majumder

Published At July 27, 2019
Reviewed AtMay 10, 2023


Starting a healthy lifestyle involves regular physical activity, eating nutritious foods, prioritizing mental health, and lowering the risk of diseases. To help fight against disease, researchers look for natural products. As a result, green tea is becoming increasingly popular. It accounts for around 20 percent of the global tea production. A recent trend for a healthy lifestyle involves green tea consumption. It is made from the Camellia sinensis plant and does not undergo the typical oxidation process of other teas. The high-quality green tea leaves are soaked briefly in cold conditions. As a result, green tea is high in antioxidant compounds. However, it is necessary to know the health benefits of green tea to obtain the maximum health effects.

What Are the Health Benefits of Green Tea?

The most relevant components in green tea are the polyphenols. Flavonoids are the most pertinent polyphenols. Out of those, catechins contain antioxidants and nutrients that have a strong effect on the body. Further, the most abundant catechin is epigallocatechin-3-gallate (EGCG), in about 60 percent concentration. EGCG has the strongest association with health. The health benefits of green tea are listed below.

1. Antimicrobial Properties: Green tea catechins combat microorganisms in various ways. They also work synergistically with antibiotics. The anti-inflammatory and antioxidant effects of green tea may also contribute to the antimicrobial effects. Studies conducted on Escherichia coli (a bacterium) found that exposure to green tea polyphenols (GTPs) resulted in its growth suppression. GTPs also damage the bacterial cell membrane, inhibit bacterial binding to host cells, and interfere with bacterial cell functions. They are also beneficial in decreasing the formation of free radicals in the body and protecting cells and other molecules from damage. These free radicals play a role in aging and other diseases. It also has many minerals. The catechins in green tea are known to have biological effects against Streptococcus mutans. Hence, green tea can reduce dental decay and improve dental health.

A study involving adults showed that green tea supplements twice daily for three months resulted in 32 percent fewer colds or influenza and about 23 percent fewer illnesses of two or more days. One must choose high-quality green tea as low-quality brands may contain fluoride (which can contribute to toxicity).

Green tea catechins are effective against viruses, parasites, fungi, and prions. The main antiviral effects include inhibiting the virus from binding host cells, inhibiting viral nucleic acid synthesis, and destroying viral molecules.

2. Improved Brain Function: Consumption of green tea is an effective dietary intervention to promote mental clarity and cognitive (conscious intellectual activity) function. These health benefits are mainly ascribed to EGCG.

Cognitive function tends to decrease with age depending on lifestyle. Regular dietary intake of green tea can reduce cognitive decline risk in women. It is because the caffeine in green tea aids in reversing oxidative processes and reducing inflammation. Hence, green tea may inhibit brain aging and maintain its normal function. Oxidative stress can induce neuronal damage and memory impairment. The positive effects of caffeine on the nervous system and preventing neurodegenerative diseases are due to the decreased deposition of amyloid-β protein in the brain (implicated in Alzheimer’s disease). EGCG is a potent neuroprotective agent in neurological disorders mediated by inflammation (due to the inhibition of free radicals).

Furthermore, the quantity of caffeine in green tea is less than in coffee. Caffeine blocks an inhibitory neurotransmitter (chemical messenger) called adenosine in the brain and raises the activity of neurons. It increases the concentration of neurotransmitters such as dopamine and norepinephrine. Green tea increases the activity of an inhibitory neurotransmitter called GABA, resulting in an anti-anxiety effect. It is also known to raise dopamine levels in the brain. Therefore, one can stay more stable, energetic, and productive after consuming it.

3. Increased Fat Metabolism: Various studies show green tea burns fat and increases metabolic rate. The caffeine content improves the physical performance of individuals by migrating fatty acids from the fat tissues and making them available for the body to get energy. However, one must remember that these effects vary from person to person due to other contributing factors, such as obesity.

4. Anticarcinogenic Effects: The mechanisms behind the anti-cancer effect of EGCG may be related to inhibiting tumor angiogenesis (new blood vessel formation), antioxidant effects, and suppressing the inflammatory processes. EGCG also inhibits growth and induces cancer cell apoptosis (programmed cell death).

The progression of colorectal (colon and rectum) cancer is significantly affected by a healthy diet and lifestyle. Consuming green tea may contribute to reducing the incidence of colorectal cancer. Supplementation of green tea extracts may also prevent recurring colorectal cancer. Research findings regarding EGCG include inhibition of growth and proliferation of gallbladder and bile duct cancer cells and decreased risk of biliary duct cancer.

Green tea works with anticancer medications and acts as a support therapy for cancer prevention. Green tea also decreases the risk of breast and prostate cancers.

5. Cardioprotective Effects: Studies have shown that green tea consumption can reduce heart diseases. It increases the antioxidant capacity of blood that prevents oxidation of LDL (low-density lipoproteins; also called bad cholesterol, which is implicated in heart diseases). Cigarette smoking is recognized as one of the risk factors for heart disease. In a study, rats were exposed to cigarette smoke and given oral EGCG simultaneously. Upon exposure to smoking, there was an increase in markers of heart injury and lipid anomalies. However, the administration of EGCG reversed them. The findings from the study suggest the protective effect of EGCG on the heart muscle by preventing inflammatory changes via reducing oxidative stress. Furthermore, green tea also lowers the risk of type 2 diabetes mellitus and hypertension.

6. Weight Reduction: Green tea improves metabolic rate and helps in weight reduction. Various studies suggest green tea in combination with a healthy diet and regular exercise for obesity management.


Data on green tea is seen in many health articles. It is because it has promising potential health benefits. Its regular consumption may support the body to maintain health and prevent disease. Studies performed in animals and cell lines have become more frequent in humans. Green tea catechins also synergize with many drugs to treat diseases and infections. Green tea is relatively inexpensive and easy to obtain for most people. As a result, it can prove to be an answer for improving health on a worldwide platform.

Frequently Asked Questions


What Does Green Tea Actually Do to the Body?

It has bioactive and antioxidant properties that improve health and increase longevity.
- Improves brain function.
- Antioxidants prevent cell damage.
- Reduces anxiety.
- Burns fats and increases the metabolic rate.
- Boosts immunity and reduces acne.
- Reduces the risk of cancer, Alzheimer's, and Parkinson's disease.
- Reduces the risk of type 2 diabetes.
- Reduces the risk of cardiovascular diseases and heart attacks.


Is It Safe to Consume Green Tea Daily?

Yes, it is safe to consume green tea daily. Studies suggest daily consumption of green tea is necessary for it to show long-term health benefits. However, excess consumption of green tea may also be harmful. People with liver diseases and pregnant women should avoid green tea.


What Time of the Day Should One Consume Green Tea?

Green tea is most effective when consumed early morning. Green tea may contain caffeine and should preferably be avoided during bedtime. Having green tea late evening or at night could cause the caffeine to keep one awake at night. Long-term effects may include insomnia as well. Green tea could also be consumed throughout the day during evening snacks.


What Happens When One Drinks Green Tea Every Day for a Month?

- Improves digestion.
- Antioxidants prevent cell damage.
- Reduces anxiety.
- Burns fats and increases the metabolic rate.
- Boosts immunity and reduces acne.
- Clears allergies and skin rashes and helps get glowing skin.
- Overconsumption of green tea can cause stomach problems and diarrhea and can even cause iron deficiency.


Who Should Avoid Green Tea?

Though green tea has many health benefits, overconsumption of green tea may be harmful to a few people. Green tea should be avoided by people who have --
- Chronic liver diseases.
- Pregnant women. 
- Breastfeeding women. 
- Children below five years of age. 
- People suffer from peptic ulcers and severe acidity.
- Conditions like GERD (gastroesophageal reflux disease).
- People with liver diseases.


Is Drinking Green Tea Before Bed Harmful?

Green tea contains caffeine, which keeps the brain active making it more difficult to fall asleep. Drinking green tea right before bedtime may also cause frequent urination, interrupt sleep, leave one tired in the morning, and have severe stomach acidity. Green tea before bedtime can also stain teeth over time as it contains tannins that cause brown-black stains. Rinsing the mouth after having green tea can prevent tooth stains. Overall it may not be a good idea to consume green tea just before bedtime.


Does Green Tea Clean the Liver?

Yes, green tea helps to clean the liver. Studies show green tea helps to keep the liver healthy. Green tea contains polyphenols that help clean the liver and improves liver function. Polyphenols and anti-oxidants support the body's normal detoxification process and help cleanse the body and different organs. Polyphenols help the elimination processes, which are mostly taken care of by the liver and kidneys.


Can Green Tea Lose Belly Fat?

Yes, green tea can help reduce fat, especially harmful abdominal fat. Subcutaneous fats lodge under your skin and around the various organs increasing insulin resistance and the risk of other organ diseases. Green tea contains catechins that help reduce body fats, including belly fat. Although many studies have shown that weight loss occurs, some also show no effect; hence, it depends on the person and other factors.


How Much Green Tea Should Be Consumed Daily?

Green tea has abundant health-benefiting compounds. Regular green tea consumption can help you lose weight and reduce belly fat and the risk of several diseases, including diabetes, heart disease, and cancer. Most people prefer to drink one or two cups of green tea daily; however, drinking three to four cups of green tea does not cause any harm. Moreover, drinking three to five cups may prove harmful and cause acidity and teeth staining in some cases.


When Should One Stop Taking Green Tea?

If a person begins to experience stomach problems, acidity, gastric reflux regurgitation, iron deficiency vomiting, constipation or diarrhea, or severe headaches, one must stop drinking green tea. Usually, researchers say green tea could be discontinued after six months and recontinued after a break of one to two months.


What Is the Healthiest Green Tea?

Matcha green tea is considered the healthiest green tea. This is because it is harvested and processed differently than regular teas. The tea bushes are protected from sunlight for just a few days before the harvest. This increases chlorophyll levels, which turns the leaves a darker shade of green and boosts amino acid production. As the whole-leaf powder is ingested, matcha contains more caffeine and antioxidants than regular green teas.


Does Green Tea Cause Kidney Stones?

No, green tea does not cause kidney stones. Instead, green tea contains high amounts of epigallocatechin gallate, which hinders kidney stone formation. The major catechin of green tea extract, epigallocatechin-3-gallate (EGCG), is a powerful antioxidant and reactive oxygen species scavenger. Thus, doctors recommend green tea to prevent kidney stones.


Which Is Healthier, Green Tea or Water?

Water is a daily necessity of life and cannot be avoided. However, green tea also contains water and provides additional anti-oxidant properties beneficial for health. Additionally, excess consumption of green tea can also harm the teeth and cause severe stomach problems. It is important to remember that green tea cannot replace water. Drinking six to seven glasses of water and one to two cups of green tea daily should suffice to have both benefits.
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Sanchari Majumder
Sanchari Majumder


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