People have consumed green tea since ancient times.
Only recently though, it’s become popular for its awesome health benefits.
Green tea has plenty of antioxidants that support your health and protect your cells from damage.
Some of the benefits of drinking green tea include:
- Enhanced focus and relaxation
- Fat loss
- Improved dental health
Below we break down the science of 11 key benefits of drinking green tea.
How is Green Tea Made?
Before exploring the benefits of drinking green tea, you might be curious about how this healthy beverage is made.
Green tea is derived from the plant called Camellia sinensis. The leaves are plucked and then heated which prevents them from oxidizing.
Once the leaves are dry, they are rolled to make the regular green tea, or ground to make powdered matcha green tea.
- There are two main variations of green tea based on the place where they come from, which is either Japan or China.
In Japan, they steam green tea leaves as a part of the drying process. This results in a mildly sweet and floral flavor.
On the other hand, Chinese dry their green tea leaves by roasting. Which leaves them with a woodsy and stronger flavor.
Both Chinese and Japanese green teas serve as a base in various herbal teas.
Benefits of Drinking Green Tea
Without any further ado, here are the 11 benefits of drinking green tea:
Improves Your Mental Performance
I like to think of green tea as coffee 2.0.
It doesn’t just keep you focused like caffeine, it also enhances your creativity and mood at the same time, thanks to l-theanine (more on that in a second).
See, caffeine in green tea is responsible for keeping you awake and alert.
- Once in your brain, caffeine binds to adenosine receptors. Usually, the neurotransmitter adenosine is bound to these receptors, which makes you feel drowsy and tired.
But caffeine has the opposite effect. Once it binds to the adenosine receptor, it increases the firing between your neurons, along with boosting dopamine. (2, 3)
Normally, this is where the benefits of caffeine end.
But green tea offers more.
- In addition to some caffeine, this healthy beverage also contains something called L-Theanine. This is an amino acid which enhances your GABA neurotransmitter and alpha brainwaves, resulting in feelings of calm and relaxed focus. (4)
L-Theanine also smoothens out the negative side effects of caffeine. This includes the infamous ‘caffeine crash’, anxiety, and jitters. (5)
The two have synergistic effects. This way, l-theanine and caffeine together work better than just one of them alone. (5)
Contains Health-Boosting Polyphenols
Green tea is a source of antioxidants. These include catechins. They neutralize free radicals and work to enhance your body’s antioxidant defenses.
Plant polyphenols such as catechins have numerous benefits. They not only protect your cells from damage but also fight inflammation, disease, and aging. (6)
Speeds Up Your Metabolism
If you’ve ever taken a look at a fat burning supplement, chances are you saw green tea listed among the ingredients.
This is because green tea is one of the best thermogenic ingredients out there.
It increases your body’s core temperature, and as a result, stimulates your metabolism to burn more calories. (7)
In addition, green tea specifically targets your fat cells for energy.
A study found that consuming green tea leads to a 17% increase in fat oxidation. And another study in men showed that green tea increases overall energy consumption by 4%. (8, 9)
Improves Insulin Response and Reduces Blood Sugar Levels
With over 400 million people suffering from type 2 diabetes, it’s no exaggeration to say that this disease has become a global epidemic.
The hallmark of type 2 diabetes is high blood sugar.
It is caused either by insulin resistance or your body’s inability to produce insulin.
Green tea may be of help here; scientists found that it can help reduce blood sugar spikes as well as improve insulin sensitivity.
A study from Japan showed that heavy green tea drinkers had a 42% less chance of becoming diabetic. (1)
Green Tea May Increase Your Lifespan
Given that green tea supports cardiovascular health and lowers the risk of cancer, it makes sense that it could increase your lifespan.
- A large Japanese study found that those who drank green tea the most had a much lower chance of dying during an 11-year study period. (10)
Another Japanese study with older adults showed even more impressive results:
Those who often drank green tea had a 76% less chance of dying during the 6 years that the study was conducted. (11)
Reduces Oxidation of LDL Cholesterol
Since it contains plenty of antioxidants, it’s no wonder that green tea can help protect your cells from free radical damage and oxidation. LDL cholesterol is particularly susceptible to oxidizing.
Catechins in green tea seem to significantly reduce LDL oxidation, preventing the build-up of plaque linked to cardiovascular issues. (12, 13)
Because of these effects, it’s no surprise to see that regular green tea drinkers have around 31% less chance of developing heart disease.
Kills Harmful Bacteria in Your Mouth & Improves Dental Health
The catechins found in green tea aren’t just antioxidants. They also fight harmful pathogens, such as viruses and bacteria. This may potentially protect you against infections.
- One particular bacteria, called Streptococcus mutans, lives in our mouth. It starts the process of plaque formation, and is among the leading causes of caries and tooth decay.
Research shows that the antioxidants in green tea reduce the growth of Streptococcus mutans, candida, and other pesky microorganisms. This leads to improved dental health and reduced risk of cavities. (14)
Green tea can improve breath smell too, according to research. (15)
Helps Protect Your Brain Cells
Green tea doesn’t just improve your short-term mental performance. It may even help you stay sharp well into old age.
The two most common neurodegenerative diseases today are Alzheimer’s and Parkinson’s. While Alzheimer’s is the leading cause of dementia, Parkinson’s is characterized by the death of dopamine-producing neurons.
According to research, green tea has compounds that protect the neurons from damage, which can potentially reduce the risk of developing neurodegenerative diseases. (16)
Green Tea May Help Against Cancer
Unfortunately, cancer is a very common cause of death worldwide.
Cancer forms when cells start multiplying uncontrollably.
It’s no secret that damage from oxidative stress can increase the likelihood of developing cancer. It’s also no secret that antioxidants might offer protection. (17)
Green tea contains some of the most powerful antioxidants in nature. So it makes sense it could potentially inhibit the growth of cancer cells. It appears to reduce the risk of several forms of cancer, including:
- Prostate cancer (18)
- Colorectal cancer (19)
- Breast cancer (20)
Of course, this isn’t definitive evidence. There’s a lot more research needed to confirm the beneficial effects of green tea on fighting cancer. But the results so far look promising.
Helps You Lose Weight
Since green tea increases your metabolism, it also improves your weight loss.
By ramping up your caloric expenditure, green tea helps your body get rid of excess fat cells. This includes the process of lipid oxidation, which green tea can increase by up to 17%. (8, 21)
Keeps You Calm and Focused
L-theanine in green tea enhances your alpha brain waves. As I repeated, this links to states of calm focus, relaxation, and creativity. This is an ideal combo; green tea won’t make you drowsy or tired but will instead give you a sustained focus without the jitters or anxiety that caffeine often brings. (4, 22)
How Much Green Tea Per Day For Optimal Health Benefits?
There are many ways you can enjoy green tea.
From drinking it hot, cold, taking it as a powder, or even taking extract capsules. All of these methods provide the critical antioxidants naturally found in green tea.
However, how much green tea should you consume for optimal benefits?
The answer seems to be somewhere between 3-5 cups per day. (23, 24)
But since everyone’s different, you may need a different amount of green tea to get the same benefits.
In fact, some studies showed that just 1 cup per day was beneficial. Others showed that 3-5 cups per day is the optimal amount of green tea. (23, 24)
There were also studies that showed no link between drinking green tea and the risk of disease. So again, the effects vary from person to person.
With that said, most studies showed that those who drank 3-5 cups of green tea per day were in better health than those who didn’t drink tea at all.
Green Tea Side Effects
While the benefits of drinking green tea are numerous, there’s also a minor risk of side effects.
This is mostly due to caffeine in green tea, which can cause jitters, anxiety, insomnia, and other side effects if you’re intolerant to it. (25, 26)
As long as you don’t go overboard with your caffeine intake (aka, no more than 200mg per day), you should be completely fine with green tea.
If you don’t notice any side effects from drinking a cup of regular coffee, then it’s unlikely green tea will cause you any negative symptoms.
There’s one more potential side effect from drinking green tea – reduced iron absorption. This is due to catechins, which are shown to lower the absorption of iron from foods. (27)
Also, if you’re under blood pressure medications, it would be smart to consult with your doctor before you start gulping green tea daily. (28)
Conclusion
Green tea is a popular tea that’s produced from green tea leaves in Asian countries.
It offers a number of health benefits, including:
- Antioxidant protection
- Cardiovascular health support
- Increased mental clarity
- Improved focus and relaxation
- Enhanced mood & creativity
- Faster metabolism
The optimal amount of green tea for health benefits varies from person to person. That said, studies found 3-5 cups per day to be the ideal number. As long as you aren’t sensitive to caffeine in green tea, you can enjoy its awesome benefits daily.
References
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The relationship between green tea and total caffeine intake and risk for self-reported type 2 diabetes among Japanese adults. (source)
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Caffeine and the central nervous system: mechanisms of action, biochemical, metabolic and psychostimulant effects. (source)
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Adenosine, Adenosine Receptors and the Actions of Caffeine. (source)
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L-theanine, a natural constituent in tea, and its effect on mental state. (source)
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L-theanine and caffeine in combination affect human cognition as evidenced by oscillatory alpha-band activity and attention task performance. (source)
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Molecular understanding of Epigallocatechin gallate (EGCG) in cardiovascular and metabolic diseases. (source)
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Obesity and thermogenesis related to the consumption of caffeine, ephedrine, capsaicin, and green tea. (source)
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Green tea extract ingestion, fat oxidation, and glucose tolerance in healthy humans. (source)
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Efficacy of a green tea extract rich in catechin polyphenols and caffeine in increasing 24-h energy expenditure and fat oxidation in humans. (source)
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Green tea consumption and mortality due to cardiovascular disease, cancer, and all causes in Japan: the Ohsaki study. (source)
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Green Tea Consumption and Mortality among Japanese Elderly People: The Prospective Shizuoka Elderly Cohort. (source)
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Green and black tea for the primary prevention of cardiovascular disease. (source)
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Inhibitory effect of Chinese green tea on endothelial cell-induced LDL oxidation. (source)
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Anti-infective properties of epigallocatechin-3-gallate (EGCG), a component of green tea. (source)
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Effect of green tea on volatile sulfur compounds in mouth air. (source)
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Neurological mechanisms of green tea polyphenols in Alzheimer's and Parkinson's diseases. (source)
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Oxidative stress, inflammation, and cancer: How are they linked? (source)
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Green tea consumption and prostate cancer risk in Japanese men: a prospective study. (source)
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An inverse association between tea consumption and colorectal cancer risk. (source)
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Green tea consumption and breast cancer risk or recurrence: a meta-analysis. (source)
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Green tea extract ingestion, fat oxidation, and glucose tolerance in healthy humans. (source)
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The neuropharmacology of L-theanine(N-ethyl-L-glutamine): a possible neuroprotective and cognitive enhancing agent. (source)
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Green tea consumption and risk of cardiovascular and ischemic related diseases: A meta-analysis. (source)
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Green tea consumption and mortality due to cardiovascular disease, cancer, and all causes in Japan: the Ohsaki study. (source)
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Caffeine consumption and self-assessed stress, anxiety, and depression in secondary school children. (source)
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Effect of caffeine on sleep. (source)
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Green tea or rosemary extract added to foods reduces nonheme-iron absorption. (source)
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Green tea: A boon for periodontal and general health. (source)