Green tea would have to be the healthiest beverage on earth. Although tea drinking has always been associated with health benefits for centuries, it's only in recent years its medicinal properties been investigated scientifically.
Benefits of green tea are largely due to its high content of flavonoids — plant-derived compounds that are antioxidants. Green tea is the best food source of a group called catechins. In test tubes, catechins are more powerful than vitamins C and E in halting oxidative damage to cells and appear to have other disease-fighting properties. Studies have found an association between consuming green tea and a reduced risk for several cancers, including, skin, breast, lung, colon, esophageal, and bladder.
Additional benefits for regular consumers of green tea include a reduced risk for heart disease. The antioxidants in green tea can help block the oxidation of LDL (bad) cholesterol, increase HDL (good) cholesterol and improve artery function. A Chinese study published recently in the Archives of Internal Medicine showed a 46%-65% reduction in hypertension risk in green tea, compared to non-consumers of tea.
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.
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.
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).
Studies show that caffeine and L-theanine can have synergistic effects. The combination 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.
If you look at the ingredients list for any fat burning supplement, chances are that green tea will be on there.
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).
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:
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).
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).
The catechins in green tea have other biological effects as well.
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).
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.
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).
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.
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 that green tea can boost the metabolic rate in the short term, it makes sense that it could help you lose weight.
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).
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):
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).
While standard fresh green tea leaves are very good, it's without doubt Matcha Green Tea is the best type of green tea with the highest amount of bioactive compounds like catechins.