health benefits and side effects of green tea Explained
Full of health-promoting compounds, green tea benefits have made it a very popular beverage.
Originated in China, the production and use of green tea have also spread to other countries in East Asia and South Asia.
Touted to be one of the healthiest beverages, Green tea is a type of tea made from the leaves of the Camellia sinensis plant which first undergo steaming, pan-frying – frying, and then a drying process of the leaves.
However, it’s a good idea to dive a little deeper into this article to get the effects of green tea on human health.
What’s In Green Tea?
Although green tea is made from the dried leaves and leaf buds of the same plant (Camellia Sinensis) from which both black tea and oolong tea are made, it does not undergo a withering and oxidation processes like all types of tea.
Scientific studies show that the health benefits of green tea are much more than that of other teas because it undergoes less processing.
Before discussing green tea good for you (health benefits of green tea), it’s good to know what’s inside your cup of green tea:

- Caffeine – brain and nervous system stimulants belong to an alkaloid family. However, consumption of too much caffeine content may affect sleep. (Discussed below)
- Amino acid L-Theanine in green tea extract is a non – proteinogenic amino acid that improves mood and helps in the reduction of stress and anxiety.
- Polyphenols
Protective polyphenols in Green Tea mean it boosts the immune system to support brain function, heart health, and reduce the risk of cancer.
“A large portion of green tea’s connection to health is tied to bioactive components called polyphenols,” says Megan Meyer, director of science communications at the International Food Information Council.
Being rich in protective polyphenols including catechins (the most notable catechin is epigallocatechin gallate), green tea bags serve as potent antioxidants (catechins may prevent cell damage) thus booster immune system against;
- Improving brain function,
- Risk of cardiovascular diseases
- Preventing a heart attack,
- Cancer prevention
The 10 Health Benefits Of Green Tea
Here are some evidence-based beneficial effects of green tea consumption.
1. Improves brain functioning
Green tea helps boost brain functioning.
The presence of caffeine and L-Theanine amino acid has powerful effects in improving brain function.
Caffeine is an active ingredient present in green tea which functions as a stimulant by blocking adenosine this way increasing the concentration of neurotransmitters that act as stimulants to brain functioning thus improving;
- Memory
- Cognitive functions
- Vigilance
- Reaction Time
- Improvement in mood swings
Daily intake of cups of green tea decreases the risk of cognitive impairments (2016 meta-analysis).
Amino acid L-Theanine acts as a blood-brain barrier to increase the production of neurotransmitters and create anti-anxiety effects.
Thus the combination of caffeine and L-Theanine in green tea improves brain function by working interdependently.
2. Weight loss
According to research, green tea boosts metabolic rate, acting as a fat-burning supplement.
A recent study has shown that green tea increases the oxidation process by up to 17% which links to direct weight loss.

Moreover, several studies show that the presence of different teas – polyphenols, catechins, and caffeine in green tea works interdependently and improves energy metabolism, by making fatty acids available for use as energy which leads to weight loss.
Although all studies don’t agree, green tea leads to weight loss by increasing the fat burning process.
3. Lowers the risk of cancer
Green tea is full of powerful antioxidants which help to protect from oxidative and cell damage that may lead to chronic diseases e.g. cancer – cause mortality.
This way green tea acts as a potent booster to the immune system. Several observational reviews and studies in recent years found that the green tea compound has reduced the risk of cancer.
According to National Cancer Institute “does not recommend for or against the use of tea to reduce the risk of any type of cancer”

And overall human studies don’t have enough shreds of evidence that green tea may reduce the risk of cancer yet several analyses and observational studies found that green tea drinkers may develop immunity against breast cancer, colorectal cancer, and advanced prostate cancer.
However, animal studies and test-tube studies found some positive impacts of green tea consumption on several different types of cancer i.e. breast, bladder, esophageal and ovarian cancers.
4. Reduces risk of cardiovascular diseases
Studies have shown that green tea may improve heart health by lowering the risk factors that lead to cardiovascular diseases.
According to the European Journal of Cardiovascular Prevention and Rehabilitation, antioxidants are concerned with the bounty of perks that rapidly improve the cell lining of blood vessels to improve the blood flow, which helps in lowering the risks of heart disease and stroke.
In short, green tea may reduce the risk of heart diseases by up to 31% by lowering the risk factors that lead to such diseases.
5. Lower blood pressure and cholesterol level
Full of antioxidants, green tea improves blood flow which in return improves heart health and can help in controlling high blood pressure.
According to the analysis of clinical research, green tea may cause a reduction in systolic blood pressure by up to 3.2 mmHg and diastolic blood pressure by up to 3.4 mmHg.
Studies in recent years have shown that consumption of up to 3 cups of green tea daily for about one year may lower the risk of high blood pressure by 65%.
Studies have shown that antioxidants found in green tea are also related to helping in lowering cholesterol levels and preventing the body from oxidative damage.
6. Lowers blood sugar level
In-vitro experiments on green tea show that it can increase insulin sensitivity in the blood which herbal teas can’t.
As it helps in better metabolic functioning and does not contain added sugar, it is suggested as a great beverage for diabetic patients.

More to it, green tea may help in lowering blood sugar levels thus helping in preventing diabetes and obesity as suggested by Mayo – Clinic researchers.
7. Beneficial effects for oral health
The presence of catechins in green tea suppresses bacterial growth thus potentially lowering the risk of infectious diseases which is beneficial for oral health.
Some shreds of evidence indicate that green tea may reduce bad breath by inhibiting the growth of oral bacteria.
8. Helps in reducing anxiety
According to researchers, the presence of amino acid L-Theanine in green tea supplements has been found to have a relaxing effect on the mind thus helping in the reduction of anxiety.
Theanine works by reducing stress-related hormones, neuron excitement, and the production of grounding alpha waves in the brain which allows the brain to relax, provide a calming effect, and keep stress at bay.
Preparing and drinking green tea acts as a relaxing ritual, one carried out by different civilizations for centuries.
However, use hot water while preparing your cup of tea to get all possible benefits because boiling water may reduce the benefits of catechins, and also adding lemon in your drink increases Vitamin C and makes catechins absorb easier.
9. Anti – Inflammatory effects
Green tea is found to have anti-inflammatory, anti-aging, antioxidant, and astringent properties.
Human clinical studies and experiments on the cellular and individual level found that epigallocatechin gallate (which is a major component of green tea) has anti-inflammatory properties.

Due to these properties, analysis shows that it is used in several dermatological products.
By improving microcirculation in affected areas, green tea acts as the most effective agent against skin problems and helps to treat acne, reducing skin inflammation, redness, and swelling.
10. Enhances Active memory
Green tea supplements enhance effective connectivity from the parietal to the frontal cortex that may induce improvement in cognitive functions.
Green tea can excite neurotransmitters that improve memory recalls.
Several observational and volunteer studies found green tea associated with treating cognitive impairments and might reduce the risk of dementia (a neuropsychiatric condition) by up to 50%.
Researchers also found polyphenols, epigallocatechin gallate (present in green tea) associated with reducing the risk of genetically predisposed disease, Alzheimer’s disease, by up to 86% if it is consumed daily.
In short, green tea can enhance a person’s working memory and cognitive performance.
Side Effects Of Green Tea
Studies show that drinking one cup of green tea daily is necessary to reap its health benefits; however, consumption of three to five cups daily also seems to be optimal.
Besides its health benefits, consumption of green tea more than optimal limits daily can cause negative side effects.
Daily intake of too much caffeine can cause several side effects in the body.

These side effects can range from mild to serious and can be fatal (very high doses of green tea).
Side effects due to caffeine may include;
- Headache
- Vomiting
- Diarrhea
- Nervousness
- Heartburn
- Dizziness
- Irregular Heartbeat
- Sleeping Problems
Moreover, excessive consumption of green tea should be avoided by pregnant and breastfeeding women.
Green Tea With A Twist - Matcha green tea
Japanese green tea, matcha tea, is a fine powder made from green tea leaves, made from the same plant as that green tea is made.
Matcha powder being high in catechin is associated with a variety of health benefits.
It is linked to cancer-fighting effects and the highest amount of antioxidants than green tea links it to several other benefits – helping prevent heart diseases, diabetes, etc.
Green Tea Dosage
The Food and Drug Administration has cited a maximum of 400 mg of caffeine per day for a healthy adult.
One 8-oz serving of green tea may contain 30mg to 50mg of caffeine while 10 to 14grams of caffeine can cause negative effects.

Is Green Tea Good For You? The Bottom Line
It’s fair to say that healthy compounds in the green tea plant make it more than a hydrating beverage.
Being rich in naturally beneficial compounds, polyphenols, it may help fight cancerous cells, reduce inflammations and help treat inflammatory bowel disease (ulcerative colitis).
Antioxidants in green tea help prevent cell damage, improve blood flow, and more importantly to all this, it can reduce the formation of free radicals and decrease risk factors that lead to cancer.
Green tea extracts are used for medicinal purposes in ointments that help to treat genital warts in approx. 24% to 60% of patients.
These healthy benefits pose better health effects and make green tea good for daily use.

The Best Herbal Tea for Headaches
6 Most Effective Teas For Headaches Headaches are a common ailment that many of us experience occasionally. They can range from migraine headaches to severe

10 Best Herbal Teas For Kidney Stones
What’s the best herbal tea for kidney stones? Kidney stones are becoming increasingly common in both men and women. It is estimated that at least

The Best Herbal Tea for Men: 10 Best Herbal Teas for Men On the Go
10 Best Herbal Teas For Men On The Go We’ve got you covered if you’re looking for the best herbal tea for men. Tea is

The Best Herbal Tea for Mucus Relief
10 Best Tea for Mucus Remedies Factors such as allergies, spicy foods, smoking, and exposure to cold weather outdoors can trigger your body to produce

Best Herbal Tea For Fertility: 15 Best Teas To Help Pregnancy
15 Best Teas to boost the chance of pregnancy Fertility problems are quite common. According to a recent study, approximately 9% of men and 11% of

Tea for Beginners: 10 Best Tasting Teas
Add Your Heading Text Here If you are a tea beginner looking for the best beverage to start your tea journey, you’ve come to the

The Best Herbal Tea For Hemorrhoids Relief ‘2023’
10 best Herbal teas for hemorrhoids Read on to learn about the best tea for hemorrhoids relief. One in three Americans experiences hermorrhoids at some

The Best Herbal Tea for Hormonal Imbalance
10 Best Herbal Teas for Hormonal Imbalance Are you looking for the best ehrbal tea for hormonal imbalance? Hormones are vital chemical messengers that coordinate

What is The Best Herbal Tea For A Cough?
10 Best Herbal Teas For A Cough A cough is one of the most common symptoms of the common cold and the seasonal flu. Unbeknown

Can You Drink Tea For Fasting?
Powerful benefits of drinking tea for fasting Drinking tea for fasting can be a great way of accelerating the benefits. Intermittent fasting has various benefits,

What Is the Best Herbal Tea for Focus and Memory? (2023)
11 Best Teas For Focus and Memory Are you looking for the best tea for focus? When it comes to mental health, there are a

What Is the Best Herbal Tea for Circulation?
9 Best Herbal Teas For Circulation Proper circulation is the foundation of overall health and general well-being. It ensures that blood and oxygen continuously flow

What Is the Best Tea for Endometriosis? (2023)
Best Teas for Endometriosis Endometriosis is a painful condition that occurs when tissues found on the lining of your uterus grow outside the uterus. This

What’s The Best Tea for Energy? Top 10 Teas for Boosting Energy
10 Herbal Teas for Energy Tony Robbins couldn’t have been more right when he said, “where focus goes, energy flows. And where energy flows, whatever

What’s The Best Tea for Period Pain and Menstrual Cramps?
9 Best Herbal Teas for Period Pain Also called dysmenorrhea, period pain is a painful sensation often felt in the lower abdomen and can spread