10 Proven Benefits of Green Tea (No. 3 is Very Impressive)

Green tea is the healthiest beverage on the planet.

It is loaded with antioxidants and nutrients that have powerful effects on the body.

This includes improved brain function, fat loss, a lower risk of cancer and many other incredible benefits.

Here are 10 health benefits of green tea that have been confirmed in human research studies.

1. Green Tea Contains Various Bioactive Compounds That Can Improve Health

Green tea is more than just green liquid.

Many of the bioactive compounds in the tea leaves do make it into the final drink, which contains large amounts of important nutrients.

It is loaded with polyphenols like flavonoids and catechins, which function as powerful antioxidants (1).

These substances can reduce the formation of free radicals in the body, protecting cells and molecules from damage. These free radicals are known to play a role in aging and all sorts of diseases.

One of the more powerful compounds in green tea is the antioxidant Epigallocatechin Gallate (EGCG), which has been studied to treat various diseases and may be one of the main reasons green tea has such powerful medicinal properties.

Green tea also has small amounts of minerals that are important for health.

Try to choose a higher quality brand of green tea, because some of the lower quality brands can contain excessive levels of fluoride (2).

That being said, even if you choose a lower quality brand, the benefits still far outweigh any risk.

Bottom Line: Green tea is loaded with bioactive compounds that can have various beneficial effects on health.

2. Compounds in Green Tea Can Improve Brain Function and Make You Smarter

Green tea does more than just keep you awake, it can also make you smarter.

The key active ingredient is caffeine, which is a known stimulant.

It doesn’t contain as much as coffee, but enough to produce a response without causing the “jittery” effects associated with too much caffeine.

What caffeine does in the brain is to block an inhibitory neurotransmitter called Adenosine. This way, it actually increases the firing of neurons and the concentration of neurotransmitters like dopamine and norepinephrine (3, 4).

Caffeine has been intensively studied before and consistently leads to improvements in various aspects of brain function, including improved mood, vigilance, reaction time and memory (5).

However… green tea contains more than just caffeine. It also has the amino acid L-theanine, which is able to cross the blood-brain barrier (6).

L-theanine increases the activity of the inhibitory neurotransmitter GABA, which has anti-anxiety effects. It also increases dopamine and the production of alpha waves in the brain (7, 8, 9).

Studies show that caffeine and L-theanine can have synergistic effects. Thecombination of the two is particularly potent at improving brain function (10).

Because of the L-theanine and the smaller dose of caffeine, green tea can give you a much milder and different kind of “buzz” than coffee.

Many people report having more stable energy and being much more productive when they drink green tea, compared to coffee.

Bottom Line: Green tea contains less caffeine than coffee, but enough to produce an effect. It also contains the amino acid L-theanine, which can work synergistically with caffeine to improve brain function.

3. Green Tea Increases Fat Burning and Improves Physical Performance

If you look at the ingredients list for any fat burning supplement, chances are that green tea will be on there.

This is because green tea has been shown to increase fat burning and boost the metabolic rate, in human controlled trials (11, 12).

In one study in 10 healthy men, green tea increased energy expenditure by 4% (13).

Another study showed that fat oxidation was increased by 17%, indicating that green tea may selectively increase the burning of fat (14).

However, I’d like to point out that some studies on green tea don’t show any increase in metabolism, so the effects may depend on the individual (15).

Caffeine itself has also been shown to improve physical performance by mobilizing fatty acids from the fat tissues and making them available for use as energy (16, 17).

In two separate review studies, caffeine has been shown to increase physical performance by 11-12%, on average (18, 19).

Bottom Line: Green tea has been shown to boost the metabolic rate and increase fat burning in the short term, although not all studies agree.

4. Antioxidants in Green Tea May Lower Your Risk of Various Types of Cancer

Cancer is caused by uncontrolled growth of cells. It is one of the world’s leading causes of death.

It is well known that oxidative damage contributes to the development of cancer and that antioxidants can have a protective effect (20).

Green tea is an excellent source of powerful antioxidants, so it makes perfect sense that it could reduce your risk of cancer, which it appears to do:

• Breast cancer: A meta-analysis of observational studies found that whomen who drank the most green tea had a 22% lower risk of developing breast cancer, the most common cancer in women (21).
• Prostate cancer: One study found that men drinking green tea had a 48% lower risk of developing prostate cancer, which is the most common cancer in men (22).
• Colorectal cancer: A study of 69,710 Chinese women found that green tea drinkers had a 57% lower risk of colorectal cancer (23).

Multiple other observational studies show that green tea drinkers are significantly less likely to get various types of cancer (24, 25, 26).

It is important to keep in mind that it may be a bad idea to put milk in your tea, because it can reduce the antioxidant value (27).

Bottom Line: Green tea has powerful antioxidants that may protect against cancer. Multiple studies show that green tea drinkers have a lower risk of various types of cancer.

5. Green Tea May Protect Your Brain in Old Age, Lowering Your Risk of Alzheimer’s and Parkinson’s

Not only can green tea improve brain function in the short term, it may also protect your brain in old age.

Alzheimer’s disease is the most common neurodegenerative disease in humans and a leading cause of dementia.

Parkinson’s disease is the second most common neurodegenerative disease and involves the death of dopamine producing neurons in the brain.

Multiple studies show that the catechin compounds in green tea can have various protective effects on neurons in test tubes and animal models, potentally lowering the risk of Alzheimer’s and Parkinson’s (28, 29, 30).

Bottom Line: The bioactive compounds in green tea can have various protective effects on neurons and may reduce the risk of both Alzheimer’s and Parkinson’s, the two most common neurodegenerative disorders.

6. Green Tea Can Kill Bacteria, Which Improves Dental Health and Lowers Your Risk of Infection

The catechins in green tea have other biological effects as well.

Some studies show that they can kill bacteria and inhibit viruses like the influenza virus, potentially lowering your risk of infections (31, 32, 33, 34).

Streptococcus mutans is the primary harmful bacteria in the mouth. It causes plaque formation and is a leading contributor to cavities and tooth decay.

Studies show that the catechins in green tea can inhibit the growth of streptococcus mutans. Green tea consumption is associated with improved dental health and a lower risk of caries (35, 36, 37, 38, 39, 40).

Another awesome benefit of green tea… multiple studies show that it can reduce bad breath (41, 42).

Bottom Line: The catechins in green tea may inhibit the growth of bacteria and some viruses. This can lower the risk of infections and lead to improvements in dental health, a lower risk of caries and reduced bad breath.

7. Green Tea May Lower Your Risk of Type II Diabetes

Type II diabetes is a disease that has reached epidemic proportions in the past few decades and now afflicts about 300 million people worldwide.

This disease involves having elevated blood sugar levels in the context of insulin resistance or an inability to produce insulin.

Studies show that green tea can improve insulin sensitivity and reduce blood sugar levels (43, 44).

One study in Japanese individuals found that those who drank the most green tea had a 42% lower risk of developing type II diabetes (45).

According to a review of 7 studies with a total of 286,701 individuals, green tea drinkers had an 18% lower risk of becoming diabetic (46).

Bottom Line: Some controlled trials show that green tea can cause mild reductions in blood sugar levels. It may also lower the risk of developing type II diabetes in the long term.

8. Green Tea May Reduce Your Risk of Cardiovascular Disease

Cardiovascular diseases, including heart disease and stroke, are the biggest causes of death in the world (47).

Studies show that green tea can improve some of the main risk factors for these diseases.

This includes total cholesterol, LDL cholesterol and triglycerides (48).

Green tea also dramatically increases the antioxidant capability of the blood, which protects the LDL cholesterol particles from oxidation, which is one part of the pathway towards heart disease (49, 50, 51).

Given the beneficial effects on risk factors, it is not surprising to see that green tea drinkers have up to a 31% lower risk of cardiovascular disease (52, 53, 54).

Bottom Line: Green tea has been shown to lower total and LDL cholesterol, as well as protect the LDL particles from oxidation. Observational studies show that green tea drinkers have a lower risk of cardiovascular disease.

9. Green Tea Can Help You Lose Weight and Lower Your Risk of Becoming Obese

Given that green tea can boost the metabolic rate in the short term, it makes sense that it could help you lose weight.

Several studies show that green tea leads to decreases in body fat, especially in the abdominal area (55, 56, 57).

One of these studies was a randomized controlled trial in 240 men and women that went on for 12 weeks. In this study, the green tea group had significant decreases in body fat percentage, body weight, waist circumference and abdominal fat (58).

However, some studies don’t show a statistically significant increases in weight loss with green tea, so this needs to be taken with a grain of salt (59).

Bottom Line: Some studies show that green tea leads to increased weight loss. It is particularly effective at reducing the dangerous abdominal fat.

10. Green Tea May Decrease Your Risk of Dying and Help You Live Longer

Of course, we all have to die eventually. That is inevitable.

However, given that green tea drinkers are at a lower risk of cardiovascular disease and cancer, it makes sense that it could help you live longer.

In a study of 40,530 Japanese adults, those who drank the most green tea (5 or more cups per day) were significantly less likely to die during an 11 year period (60):

• Death of all causes: 23% lower in women, 12% lower in men.
• Death from heart disease: 31% lower in women, 22% lower in men.
• Death from stroke: 42% lower in women, 35% lower in men.

Another study in 14,001 elderly Japanese individuals aged 65-84 years found that those who drank the most green tea were 76% less likely to die during the 6 year study period (61).

Take Home Message

If you want to buy quality organic green tea (or green tea extract), then there is an excellent selection with thousands of customer reviews on Amazon.

In order to feel better, lose weight and lower your risk of chronic diseases, then you might want to consider making green tea a regular part of your life.

Green Tea: Side Effects And Who Must Not Consume It

Green Tea Side Effects And Who Must Not Consume It

Green tea is one of the oldest herbal teas known to man. It gained quick prominence in the west after its purported health benefits, the most popular of them- as an effective tool for weight loss. Some of these health benefits have many studies backing them while some do not. Due to the positive spotlight, green tea has enjoyed, some of its side effects are often overlooked. But it’s important to understand that Green Tea also has some limitations and a few of them are highlighted below.

The tannins present in the green tea increase the stomach acid which may cause stomach ache, nauseous feeling, or cause constipation. Thus, green tea is not consumed on an empty stomach in Japan and China.

Green tea is mostly safe for adults when consumed in moderation. Green tea extract is also considered to be generally safe for most people when taken orally or while being applied topically on the skin for a short period of time. However, drinking too much green tea, more than 5 cups a day is considered to be unsafe. The side effects occur due to the caffeine present in the tea, which may include some or all of these symptoms:

.Mild to serious headaches
.Nervousness
.Sleep problems
.Vomiting
.Diarrhoea
.Irritability
.Irregular heartbeat
.Tremor
.Heartburn
.Dizziness
.Ringing in the ears
.Convulsions
.Confusion

Who Must Not Consume Green Tea?

Green Tea has been found to cause certain problems when taken excessively or cause problems to some people who suffer with certain ailments:

1. Stomach Problems: The tannins present in the green tea increase the stomach acid which may cause stomach ache, nauseous feeling, or cause constipation. Thus, green tea is not consumed on an empty stomach in Japan and China. It is best to drink green tea after a meal or in-between meals. People with peptic ulcers or acid reflux should not consume green tea excessively. A 1984 study concluded that tea is a potent stimulant of gastric acid, which can be reduced by adding milk and sugar.

2. Iron Deficiency: Green tea seems to reduce the absorption of iron from food. Drinking very high doses can actually be fatal. The fatal dose of caffeine in green tea is estimated to be 10-14 grams (150-200 mg per kilogram). Green tea can also reduce the bioavailability of non-heme iron. A 2001 study reports that green tea extract reduces the absorption of non-heme iron by 25%. Non-heme iron is the primary type of iron in eggs, dairy and plant foods such as beans, so drinking green tea with these foods may lead to reduced iron absorption. However, Vitamin C increases non-heme iron absorption, so you can squeeze lemon into your tea or consume other vitamin-C rich foods, such as broccoli, with your meal. In addition, drinking tea between meals seems to have little effect on iron absorption, according to the National Cancer Institute.

3. Caffeine Caution: Like all teas, green tea contains caffeine and excessive caffeine intake can lead to nervousness, anxiety, abnormal heart rhythm and shakiness. Some people have a natural low tolerance for caffeine, and they will suffer these symptoms even when ingesting small amounts. High caffeine consumption can also hinder calcium absorption, affecting your bone health and increasing the risk of osteoporosis. To help prevent caffeine-related problems, limit green tea intake to 5 or fewer cups per day

4. Pregnancy and Breast-Feeding: Green tea contains caffeine, catechins and tannic acids. All three substances have been linked to pregnancy risks. If you are pregnant or breast-feeding, green tea in small amounts, about 2 cups per day safe. This amount of green tea provides about 200 mg of caffeine. However, drinking more than 2 cups of green tea per day is unsafe and has been linked to an increased risk of miscarriage and other negative effects. Also, caffeine passes into breast milk and can affect a nursing infant. In addition, drinking a large amount may cause neural tube birth defect in babies.

5. Anaemia: Green tea catechins can cause a decrease in the absorption of iron from food. If you have iron-deficiency like anaemia, the National Cancer Institute recommends consuming tea between meals. If you like to drink green tea with your meal, then studies show you should eat foods that enhance iron absorption. Foods high in iron include meats such as red meat and foods high in Vitamin C, such as lemons.

6. Anxiety Disorders: The caffeine in green tea might is said to make anxiety worse.

7. Bleeding Disorders: Caffeine in green tea might increase the risk of bleeding.

8. Heart Conditions: Caffeine in green tea might cause irregular heartbeat.

9. Diabetes: Caffeine in green tea might affect blood sugar control. If you drink green tea and have diabetes, monitor your blood sugar carefully.

10. Diarrhea and IBS: The caffeine in green tea, especially when taken in large amounts, can worsen diarrhea and symptoms of IBS.

11. Glaucoma: Drinking green tea increases pressure inside the eye. The increase occurs within 30 minutes and lasts for at least 90 minutes.

12. High Blood Pressure: The caffeine in green tea might increase blood pressure in people with high blood pressure. However, this does not seem to occur in people who regularly drink green tea or other products that contain caffeine.

13. Should not be given to Children: The tannins in green tea may block nutrients absorption such as protein and fats in children. It may also lead to over stimulation because of the caffeine present in the green tea.

14. Liver Disease: Green tea extract supplements have been linked to several cases of liver damage. Green tea extracts might make liver disease worse. Severe liver disease, as the level of caffeine in the blood may build up and last longer.

15. Osteoporosis: Drinking green tea can increase the amount of calcium that is flushed out in the urine. Caffeine should be limited to less than 300 mg per day (approximately 2-3 cups of green tea). It is possible to make up for some calcium loss caused by caffeine by taking calcium supplements.

Can People On Medication Drink Green Tea?

Green tea must not be taken along with these medications as it is known to cause negative reactions.

1. Highly Interactive: Stimulant drugs like Amphetamines, Nicotine, Cocaine and Ephedrine.
2. Moderately Interactive: Adenosine, Quinolone antibiotics, Birth control pills, Cimetidine (Tagamet), Clozapine (Clozaril), Dipyridamole (Persantine), Disulfiram (Antabuse), Estrogens pills, Fluvoxamine (Luvox), Lithium, Medications for depression (MAOIs), Hepatotoxic drugs, Medications that slow blood clotting (Anticoagulant / Antiplatelet drugs), Pentobarbital (Nembutal), Phenylpropanolamin, Riluzole (Rilutek),Theophylline, Verapamil and Warfarin.
3. Slightly Interactive: Alcohol, Fluconazole, Anti-diabetes drugs, Mexiletine (Mexitil) and Terbinafine.
For a more detailed description, read the article here.

How to Consume Green Tea?

The United Kingdom Tea Council recommends drinking not more than 6 cups of tea a day. For the best health benefits, 3 to 4 cups is recommended. However, doses of green tea vary significantly, but usually range between 1-5 cups daily is considered safe. The commonly used dose of green tea is based on the amount typically consumed in Asian countries, which is about 3 cups per day, providing 240-320 mg of the active ingredients, polyphenols. To make tea, people typically use 1 tsp of tea leaves in 8 ounces of boiling water.

Drink green tea when it’s freshly made but slightly cooled. Scalding tea can damage your digestive system. Moreover, recent studies suggest that too much hot tea can promote throat cancer. Compounds in tea like catechins, theanine, and vitamins C and B diminish over time through oxidation, so the health benefits are strongest with fresh tea. If you’re brewing the same tea leaves, brew them in moderation. With each successive infusion, cancerous substances in the leaves themselves (often pesticides) are drawn out and can even be toxic. Old tea can also harbour bacteria, especially since its antibacterial properties diminish with time.

Tea Dosage For Ailments

.Headache: Tea providing up to 250 mg of caffeine per day, or approximately 3 cups of tea per day.
.Improved thinking: Tea providing 60 mg of caffeine, or approximately one cup.
.Reducing cholesterol: Drinking 10 or more cups per day has been associated with decreased cholesterol levels. Theaflavin-enriched green tea extract, 375 mg daily for 12 weeks, has also been used for lowering cholesterol.
.Preventing Parkinson’s disease: Men consuming 421-2716 mg total caffeine (approximately 5-33 cups of green tea) daily have the lowest risk of developing Parkinson’s disease. However, a significantly lower risk is also associated with consumption of as little as 124-208 mg of caffeine (approximately 1-3 cups of green tea) daily. In women, more moderate caffeine consumption seems to be best, equivalent to approximately 1-4 cups of green tea per day.

Topical Application Dosage

.Human papillomavirus (HPV) infections of the cervix: Green tea ointment alone or in combination with oral green tea extract, twice weekly for 8-12 weeks.
.Genital warts: a specific green tea extract ointment (Veregen, Bradley Pharmaceuticals) providing 15% kunecatechins applied three times daily to external warts for up to 16 weeks has been used.

Conclusion

You don’t have to quit drinking your favourite cuppa green tea, but if you have any of the above mentioned medical conditions or taking prescription drugs, exercise caution and consult your doctor about how many cups you can have per day. Moderation is key to enjoy the full benefits of green tea.