Green Tea: Benefits, Side Effects & Dosage

1 Green Tea benefits and side effects

Green tea, native to China and India, has been hailed across the globe for its health benefits for centuries.

One of the healthiest drinks on the planet, green tea leaves can be steeped to make tea, or sipped whole (in the form of matcha powder). Both the leaves and the tea itself can also be incorporated into cooking, malign this one of the most versatile forms of tea available.

If you have already read our article covering the best natural energy drinks, then you'll know all about the benefits of green tea and how it is a prominent ingredient on the health market.

After water, tea is the second most consumed drink in the world. Of course, this includes all forms of tea; white, Oolong, black, herbal and so on.

In this article, we have created an in-depth guide to provide you with everything you need to know about green tea. The contents is as follows:

Before we get started on exploring the benefits of green tea, if you have a particular interest in the nutritional side of fitness, why not head over to OriGym's Level 4 Advanced Sports Nutrition Course where you can enquire about enrolling onto our REPs certified qualification. Alternatively, you can download our free course prospectus for more information. 

What is Green Tea?

1 Green Tea benefits and side effects

Green tea is a type of tea made from leaves that have not undergone the same production processes as other teas. With their process, they are not subjected to withering or oxidation, so the tea has a unique taste which differs substantially from black tea. 

Many different variants of green tea exist, but they are all based largely or wholly on the Camellia sinensis leaf, which gives the tea its notable light green colour. Common variations of green tea include Jasmine and Matcha, which are hugely popular and offer slightly different tastes. 

Green tea extract benefits are wide ranging, and studies have been extensive. Green tea has been linked to everything from improved brain function, healthier skin and even increased fat burn. Due to the type of leaf used and associated production methods, green tea is also substantially lower in caffeine than coffee or other teas, which is another reason that it is loved by so many.

What's more, those on specialist diets can also reap the benefits of green tea; as you can see on our best keto drinks guide, green tea is highly recommended for those following the high-fat diet.

Additionally, green tea is rich in antioxidants, so drinking green tea benefits the body by mopping up harmful free radicals and toxins associated with disease. Green tea has its origins in China but spread rapidly throughout the East, and is now popular across the world for its delicate taste and many health benefits. It is usually sipped just as you would any tea, but green tea supplements are becoming increasingly available.

What are the benefits of green tea?

2 The benefits of drinking green tea

Traditionally, green tea was used in both Chinese and Indian medicines that were designed to control bleeding and heal wounds, improve heart and mental health, regulate the body’s temperature, as well as aid digestion. 

This came as a result of green tea leaves possessing nutrients and plant compounds, including antioxidants called catechins, which were and continue to be proven to have a number of positive health effects.

In more recent studies there has been evidence to suggest that green tea could potentially have advantages on conditions and issues from type 2 diabetes and weight loss to Alzheimer’s disease and liver disorders.

It is important to note that some of the following health benefits of green tea are still being researched and debated, therefore more evidence is required before they can be proved definitive.

So, what are the health benefits of drinking green tea?

#1 Green tea boosts metabolism

benefits of green tea supplements

It might seem hard to believe that something as simple and fundamentally uncomplicated as a cup of tea can alter how your body burns through fat, but that’s one of the most profound green tea health benefits. 

Impressively, green tea has been proven to actually boost your metabolism, helping your body to process fat molecules much faster. The effect is so marked that green tea is often included in weight loss supplements as one of the main active ingredients.

But you'll already know all that if you've read our guide on how to get a summer body, right?

Studies have borne this out again and again. One 2007 report showed that green tea increased caloric burn by 4%, another that the oxidation of fat was increased by 17%. These are extremely positive results, and suggest that green tea has some real, tangible benefits on how the body processes fat. That, of course, makes it a fantastic weight loss aid. 

A longer-term study in comparison to the aforementioned confirmed that green tea does not simply supply a ‘quick-fix’, either. Findings from the 2005 report showed that green tea has proven benefits for improving weight management in the long run.

The health benefits of green tea weight loss supplements extend further still. Green tea doesn’t include anywhere near as much caffeine as coffee or even black tea, but the little it does contain helps with weight loss, too. Caffeine is known to give athletic performance a boost because it stimulates the body to use fat molecules for energy.

More generally, caffeine is included in energy drinks and supplements for its performance boosting credentials. Studies have shown that taking caffeine before a workout increases athletic performance by approximately 11-12%, which makes a huge difference if you’re trying to lose weight. 

Increased fat burn is one of the most important green tea benefits for men and women looking to lose weight, and it is why so many people choose the tea, or even opt for supplements.

#2 It decreases the risk of type 2 diabetes

pea protein benefits

Mounting evidence suggests that a green tea supplement benefits not only those suffering from type 2 diabetes, but those at risk of developing it in the first place. Type 2 diabetes is triggered by a combination of elevated blood sugar and impaired insulin sensitivity, but green tea can make a positive impact in both those areas.

Green tea has been proven to boost insulin sensitivity while simultaneously lowering blood sugar levels, two factors which are absolutely crucial for the management of diabetes. 

It's so effective, in fact, that one study conducted in 2009 found that people who consume a lot of green tea (at least three cups a day) are approximately 42% less at risk of even developing type 2 diabetes to begin with. Another far wider ranging study demonstrated that regular green tea drinkers were 18% less at risk.

It is thought that the antioxidant properties of green tea, along with its many polyphenols and polysaccharides, are responsible for that decreased risk. It is also worth remembering that those studies looked at pure green tea. 

Mixing green tea with other ingredients, like milk or sugar, will offset some of the benefits, and consuming large amounts of sugar in tea will likely have a detrimental rather than positive affect.

If you're particularly interested in its aid for diabetes use and would like to develop your knowledge on this field further, here at OriGym we provide a REPs accredited Level 4 Diabetes Control and Weight Management course, where you establish the awareness and skills to help clients who suffer from diabetes to manage their weight through physical activity.

It is always important to balance green tea benefits and side effects, but there are very few of the latter to worry about. Excessive caffeine consumption (from drinking huge amounts of the tea) is always a risk, and that’s especially true if you brew super strength cups. Other than that, green tea is remarkably safe, and drinking it routinely will cut your risk of developing type 2 diabetes or, if you already suffer from it, help you bring the disease back under control.

#3 Great for cardiovascular health

6 what are the health benefits of green tea

One of the most commonly touted pure green tea benefits is on cardiovascular health. There have been plenty of studies into this, all of which have returned promising results. The largest of these studies came from Harvard Medical school, who took a sample of 40,530 individuals and instructed them to consume five or more cups of tea each day. The results were startling. 

The subjects who drank the most tea had a 26% lower chance of dying from a heart attack or stroke. Startlingly, their all-cause mortality (i.e death from any disease) was 16% lower than individuals who drank less than one cup per day. That shows that not only does green tea lead to dramatically improved cardiovascular health, but it generally improves life expectancy. On the other hand, black tea does not have any effect on heart health. 

There are quite a few reasons behind this impressive finding. One of the most profound green tea extract benefits is how it reduces LDL cholesterol (the bad kind) as well as levels of triglyceride. Experiments conducted using the polyphenols in green tea (rather than the tea itself) seem to suggest that those compounds are responsible for the profound benefits.

Green tea reduces blood pressure and can also help with weight loss - both of which are two big risk factors for heart disease. The tea’s fat burning credentials are especially important to bear in mind too, and might be responsible for a better cardiovascular outlook. Weight loss is always recommended for those suffering from poor heart health, and green tea’s efficacy in that area is just as useful as its high polyphenol count.

It may benefit you to learn more about the types of body fat and how they affect the cardiovascular system for you to understand thoroughly how green tea aids a healthier system.

#4 It's great for the skin

green tea benefits for skin

Green tea benefits for skin are multitudinous and you’ll find green tea extracts in a variety of skincare products. Many of those benefits are associated with green tea’s high antioxidant content which gives it its anti-aging properties. Free radicals and other toxins are responsible for the wrinkles, lines and blemishes that appear across the skin, but antioxidants eliminate those molecules from the body; the result is healthy, clear skin.

More specifically, green tea contains the antioxidant Epigallocatechin Gallate (EGCG). EGCG regenerates and rejuvenates skin cells, essentially helping to produce new cells to replace dead ones, which in turn equates to healthier skin which has the much sought “glow.” 

Along similar lines, green tea is rich in Vitamins B and E, both of which are essential to the elasticity of the skin and make it more supple. In a 2005 study, which explored the effects of a combination regimen of topical and oral green tea supplementation on the characteristics of photoaging, academics were able to prove that participants who were treated with the combination showcased an improvement of skin elasticity. 

Furthermore, in a 2013 study published in Dermatologic Therapy evaluating the effects of cosmetic formulations containing green tea, the results suggested that cosmetic formulas that contain green tea extract have improved skin microrelief and have pronounced moisturising effects - supporting evidence that green tea has skin benefits.

Additionally, the benefits of milk thistle also include advantages for the skin.

You’ll often find collagen in skin care products, especially those that claim anti-aging properties, this is because collagen makes the skin firmer and decreases wrinkles. Vitamin B plays a crucial role in collagen production in the body, so that is yet another reason why it leaves your skin looking younger. 

Tannins in green tea are a great treatment for oily skin and are especially useful for clogged pores. Tannins force the pores to shrink, which makes it less likely that they’ll become clogged over time. Furthermore, they also help to moderate how much oil the skin produces, which is great for acne and can prevent blemishes.

Incidentally, green tea benefits for hair are similarly impressive. Green tea shampoo is quite a common sight on the supermarket shelves as of recent - EGCG is responsible again. It facilitates hair growth and can even repair damaged hair follicles which results in a fuller, thicker and healthier head of hair.

#5 Jasmine tea soothes aches and pains

Health benefits of green tea

Jasmine tea is a form of green tea that includes aromatics from the jasmine leaf, giving it its signature taste and scent. Jasmine is one of the most popular types of green tea and possesses many of the same benefits. It is loaded with antioxidants (so expect all those associated benefits) and has a similar outlook for increased fat burn and cardiovascular health. 

Additional benefits are mostly centred around muscle aches and pains. Studies conducted by the American College of Rheumatology highlight one of jasmine tea’s main components, epigallocatechin gallate, as the reason for this. The compound has an important role to play in preventing the inflammation associated with arthritis, muscle and joint soreness. 

Antioxidants play a role in this also and generally contribute to decreased muscle inflammation. As a result, this means that jasmine green tea benefits arthritis sufferers greatly, but it also has pronounced effects elsewhere. 

This can be supported by the findings of a 2012 study, where research concluded both green and black tea leaves possessed a marked anti-inflammatory effect against the denaturation of protein, with green tea being found to be more active than black tea.

It may be surprising to know that the benefits of blueberries also include anti-inflammatory properties, so if green tea is slightly too earthy for your tastebuds, these small but mighty berries are a great alternative.

Anybody performing intensive workouts, be that long distance runners, weightlifters or bodybuilders, will benefit from reduced inflammation. The combination of potent antioxidants and epigallocatechin gallate protect the muscles and generally decrease recovery times, therefore drinking jasmine green tea following an intensive workout is a brilliant way to reduce soreness the next day and allow you to get back to work faster.

The only caveat with jasmine tea is for those who suffer from an iron deficiency; the tea is still suitable, but it is advisable to drink it between meals (rather than while you’re eating) and leave roughly an hour after you’ve finished. People with a sensitivity to caffeine should be similarly cautious, but jasmine tea is otherwise extremely safe.

#6 It can boost brain function

7 health benefits of matcha green tea

Green tea has always been anecdotally linked to increased cognitive function, but now there are an increasing number of studies to back this up. 

In its simplest form, green tea contains caffeine, which is a stimulant that gives concentration, focus and mental energy a boost. Caffeine is renowned for lifting that early morning “brain fog” and can give you a real boost as you start the day. The health benefits of green tea extract on the brain extend much further than that, however.

In a three year study, conducted between 2015 and 2018, researchers explored the brain functions of those who drank tea in comparison to those who did not. The findings show that the brain regions of individuals who consumed either green, oolong or black tea at least four times a week for a period of about 25 years were interconnected in a more efficient way.

Green tea is rich in L-theanine, which is one of the few organic compounds capable of crossing the blood/brain barrier. With this, it means that it has a direct and tangible effect on cognitive function, more so than anything else that we ingest. L-theanine has all kinds of mood enhancing benefits as it stimulates GABA receptors in the brain, which have the effect of releasing feel good chemicals including dopamine. 

Those receptors also stimulate alpha waves in the brain, which boost function. These effects, combined with the caffeine, offer undoubted neurological benefits, but since green tea contains a lot less caffeine than coffee or even black tea, the wave of energy is smoother, and comes without crashes, jitters, or any accompanying mental slump. The two work hand in hand to give those who consume it an undeniable mental lift.

This has knock on effects for diseases of the brain, including Alzheimer’s and Parkinson’s. Green tea powder benefits those at risk or already suffering from these diseases. Catechin compounds in the tea are responsible for this, and numerous laboratory studies have shown that they might lower your risk of developing a neurological condition.

Alternatively, another fresh produce that carries benefits for the brain and cognitive function is the eggplant. Read more about how it does this in our benefits of eggplant guide.

#7 It has antiviral properties

pea protein powder benefits

One of the health benefits of green tea tablets and supplements, which is coming increasingly into focus amongst the scientific community, is its antiviral and antibacterial property. 

More and more studies are being conducted in this area, and a consensus is gradually being reached. It might seem difficult to believe that a simple cup of tea can combat viruses, but green tea contains some very special ingredients.

Catechins are responsible for green tea’s antimicrobial properties. Four, in particular, are especially effective: epicatechin, epicatechin-3-gallate, epigallocatechin and epigallocatechin-3-gallate. 

Crucially, by drinking green tea you spread these compounds fairly evenly throughout your body. They’re not only useful for treating pre existing diseases, but actually warding off illness in the first place. A cup or two of green tea each day can really help your body fight off infection, or stop it taking hold to begin with.

In a 2017 review which summarised the developments regarding the antiviral activities of green tea catechins (GTCs), the researcher concluded that GTCs, with particular mention to epigallocatechin-3-gallate (EGCG), have antiviral effects against diverse viruses.

Antioxidants also play a part, but the catechins are the true stars of the show. Many choose to move beyond simply brewing up green tea and opting for a fully fledged supplement in the form of tablets. This is an excellent way to utilise those antiviral properties, and taking green tea tablets benefits anybody who is under the weather, or wants to ward off infection over the winter. 

Tablets are widely available from health shops, including Holland and Barrett, and they’re a much more convenient way of increasing your intake without having to spend time brewing the tea. You’ll get all the same benefits, including those all important antiviral properties.

#8 Matcha green tea protects the liver

8 benefits of green tea tablets

Matcha is another of the most popular types of green tea. It is similar to other varieties, save for a few small but important differences. Rather than being dissolved in water, matcha tea is drunk suspended. It also contains higher levels of epigallocatechin gallate than other types of green tea. 

One of the most profound health benefits of matcha green tea is how it specifically works on the liver. Studies on rats have linked the consumption of matcha green tea to improved liver function. Rats suffering from diabetes were given a 16 week course of matcha green tea. At the end of the study, those rats suffered far less liver damage.

A follow up study involving 12 human subjects yielded similarly favourable results. Liver enzymes are markers for ongoing liver damage, but people given green tea extract for 12 weeks showed considerably fewer enzymes at the end of the study. These are two significant results, but there have been plenty more studies linking matcha green tea with a healthier liver that’s protected from damage.

Matcha green tea benefits those who might be more at risk of developing liver disease or are already suffering. The tea is very similar to standard green tea, but it’s also widely available as a supplement. Tablets and capsules are popular, and they’re a simple way to up your matcha intake on the move. Supplements are far more convenient than brewing the tea, and a great way to protect your liver.

#9 It’s high in antioxidants 

green tea benefits

As you have likely noticed, many of the health benefits of green tea are linked to its high antioxidant content. Green tea is bursting with these compounds, and they're one of the most important ingredients to overall health. The usefulness of antioxidants can’t be overstated, which is why you’ll routinely see them advertised on food packaging and touted as essential. 

Antioxidants have the dual role of mopping up harmful free radicals in the blood and protecting cells from oxidative damage. The former is linked to a decreased risk of cancer and other diseases. 

Free radicals also play a role in other diseases including heart disease, so cutting them down is important. Their presence in the body has a negative effect in the long run, and not all foods will help to get rid of them.

A buildup of free radicals causes oxidative damage and leads to cellular breakdown, again associated with the onset of diseases like cancer. The benefits of drinking green tea include topping up your body's antioxidant store, getting rid of those free radicals and protecting your cells from oxidative damage.

Antioxidants also have a role in muscle repair and maintenance, which is why green tea (and green tea supplements) are favoured by so many bodybuilders. Oxidative stress affects how quickly muscles can repair themselves after an arduous workout, and an excess of free radicals leads to inflammation and soreness the next day. Foods rich in antioxidants are known to shorten the recovery phase, so green tea makes a brilliant post workout drink.

For more antioxidant sources, our article highlighting the best superfruits to add to your diet today is an inisghtful read.

#10 Great for relaxing

benefits of green tea weight loss

There’s nothing more soothing than settling down with a steaming cup of warm tea after a long day, but the health benefits of green tea for anxiety and stress are far more profound than simply nestling away with a cuppa. Research in this area links green tea’s relaxing vibes to theanine (the same compound that we talked about earlier in relation to anxiety). 

Theanine stimulates the GABA receptors in the brain, which in turn release feel-good chemicals that help to combat stress, anxiety, and generally put you in a better frame of mind. Antioxidants are involved again, too. They clear toxins from the blood, contributing to better overall health and a more general feeling of wellbeing. 

This means that your cup of lipton green tea benefits your brain and body by releasing chemicals like dopamine and GABA, which gently ease you into a more relaxed state of mind. The tea makes you feel much calmer and clears away any issues related to brain fog, mental congestion and impaired memory recall.

Caffeine would usually be expected to work the opposite effect, but green tea contains far less caffeine than coffee and even common black tea. That means that you can enjoy the relaxing benefits of green tea tablets and supplements without having to worry about getting jitters or being kept awake hours after you’ve drank the tea. 

Another effective way to relax your body that many people overlook is through yoga. If you're new to the practise, you may want to start by downloading one of the best free yoga apps that we have recommend in our shortlist.

Green tea's anti-anxiety, relaxing qualities are one of the best green tea benefits for men and women who want to wind down after a stressful day.


#11 It remedies bad breath

benefits of green tea

One of the more surprising and unknown benefits of drinking green tea is how it can improve the smell of your breath. 

Bad breath is generally caused by a mixture of poor diet and the buildup of bacteria in your mouth. No matter how frequently you brush, this bacteria can sometimes become stuck in hard to reach parts of the mouth, for example between teeth, and give your breath an unpleasant aroma.

As previously stated - a number of times, one of the most profound of the many green tea benefits is its high antioxidant content. In this way, green tea functions as a type of potent mouthwash. 

The antioxidants rinse your mouth and help to cleanse any built up bacteria. Rinsing with green tea is an excellent way to clean your mouth, especially if you combine it with good oral hygiene, flossing and brushing.

Moreover, the buildup of toxins in your body can lead to bad breath too. Free radicals and harmful molecules have a knock on effect in your mouth. Antioxidants help to take them out of the bloodstream and contribute to overall well being. That, of course, translates into better smelling breath.

Of course, green tea is even more effective if you drink it as a substitute for other, more unhealthy drinks. For example, sugar rich sodas and fizzy drinks are catastrophic for the teeth (not to mention the rest of the body). 

The acid and sugar in these drinks leads to decay and can cause your teeth to rot with cavities. The result, of course, is bad breath. Swapping these drinks for healthy green tea will not only cleanse your mouth, but stop you developing bad breath again in the future.

#12 Can prevent tooth decay

9 green tea tablets benefits

Following on from the previous point, another of the biggest health benefits of green tea is that it can help prevent tooth decay. This is especially pronounced in children who often favour sweet snacks and drinks that can damage their teeth, but people of all ages will feel the benefits. Tooth decay is caused by bacterial build up in the mouth. 

That bacteria turns carbohydrates into energy, but produces acid as a by-product. The acid then breaks down your teeth, leading to holes and cavities. That, in turn, opens the way for bacteria to find its way into the soft dentine in the core of the tooth. Dentine is soft, so the process of decay accelerates, and all kinds of problems can develop, potentially even leading to teeth having to be removed.

According to a 2016 study published in The Open Dentistry Journal, researchers found that green tea may reduce oral bacteria which, in turn, can promote the health of teeth and gums. The academics believe that antimicrobial molecules, or the catechins as you may now know them as, that are found in green tea have the potential to kill bacteria associated with tooth decay and gum disease.

Pure green tea benefits the teeth in several ways, some direct, others indirect. The most obvious benefit comes when you swap sweet drinks for green tea. That cuts down on the problematic sugar, but green tea has a host of benefits in its own right. 

Drinking green tea benefits anybody suffering from tooth decay because of its antibacterial properties. Antioxidants cleanse the mouth and get rid of the causes of decay. That’s why you’ll sometimes find green tea extract in toothpaste, where it’s used as a cleanser. 

Moreover, green tea has been linked to a decreased risk of developing oral cancers and the properties that help to prevent tooth decay are also good for your gums. Of course, all of this good work is undone if you add sugar or honey to your cup of green tea, so try to keep it as pure as possible.

#13 Green tea is substantially lower in caffeine

3 benefits of green tea capsules

Caffeine is by no means unhealthy, and in fact can have great advantages when consumed in low doses. Caffeine is associated with all kinds of benefits, including: increased focus, elevated brain function and even lower blood pressure. Athletes often favour caffeine in their supplements, and we can all benefit from a quick pick me up every so often.

The downsides of caffeine only come in when it’s consumed to excess. Drinking lots of high caffeine drinks in a day can lead to anxiety, jitters, and unpleasant spikes/energy crashes. A glut of caffeine can also increase your heart rate, cause digestive problems and create insomnia. This is yet another reason as to why green tea is a great drink. It helps you get all the benefits of caffeine in a much smaller dose.

A single cup of coffee equates to more than three cups of green tea, and green tea is even substantially lower in caffeine than black tea. Pure green tea benefits those who do not generally tolerate caffeine well but still want the lift and neurological benefits associated with it. 

Green tea also delivers a much smoother energy release, in part due to the lower caffeine count but also because of the high Theanine content. Theanine makes you feel more relaxed, so you’ll get all the energy of the caffeine without any of the anxious downsides. 

Caffeine gets a bad reputation which is in part justified, however green tea is a fantastic way to consume it responsibly. You can safely enjoy all those green tea health benefits without having to worry about excess caffeine.

However, if you're not too concious of your caffeine intake, you may find our best running supplements to fuel your run a great read.

#14 Can lower your risk of stroke

pea protein content

Many of the combined benefits of drinking green tea have the cumulative effect of reducing your stroke risk quite dramatically. A particularly wide ranging study involving 83,000 participants found that those who drank green tea were 20% less at risk from a stroke than those who didn’t. 

These numbers included coffee drinkers too, but there’s no doubt that green tea’s many health benefits certainly have a huge effect.

Green tea is known to lower blood pressure and decrease levels of harmful cholesterol, both of which play a big part in making you more at risk of suffering a stroke. That high antioxidant content also has an important role. By mopping up harmful free radicals and toxins, antioxidants decrease inflammation, which can lead to a heightened risk of stroke. 

Similarly, one of the major health benefits of green tea tablets and supplements is how they reduce the chances of you developing type 2 diabetes which is, as you might imagine, another risk factor associated with stroke. Green tea has proven compounds that prevent excessive blood clotting, and we’ve explored its effect on the brain in detail earlier on this list.

The exact mechanisms which make green tea effective at lowering stroke risk aren't fully understood yet, but the studies do show a clear correlation. It’s likely that the effect is cumulative, and green tea’s many benefits combine to reduce risk factors around stroke. 

It can even help you lose weight more effectively, which is vital since obesity is an underlying risk factor too. There’s room for much more study in this area, but for the time being there’s no doubt that drinking green tea everyday cuts your risk of suffering a stroke later in life.

#15 It's brilliant for the immune system

10 benefits of green tea extract

The health benefits of green tea on the immune system have always been talked about anecdotally, but science is beginning to catch up and understand the mechanisms behind this process. 

Green tea has long been touted as a way to ward off illness and boost the immune system, which is one of the big benefits of green tea capsules. Scientists are now fairly confident about how it manages to accomplish this feat.

Studies suggest that green tea has the dual effect of suppressing autoimmune diseases while simultaneously boosting the number of T cells in the body. In essence, green tea helps the immune system to function correctly. T cells are a vital component of how our immune systems work. They attack unwanted invaders, destroy viruses and generally ward off diseases.

By boosting our bodies capacity to produce T cells, green tea gives us more weapons to fight off illness. Intriguingly, studies suggest that green tea not only bolsters but also helps to moderate our immune systems. 

Compounds in the tea stop the body overproducing those T cells, and prevent the immune system from attacking itself, which can be a problem in autoimmune diseases. 

A number of prescribed drugs are available that do that too, but they come with a plethora of side effects and associated risks. One of the big green tea supplement benefits is how few side effects they have, making them an exceptionally safe way to support your immune system. 

Of course, the high antioxidant count in green tea also plays a part in warding off diseases like cancer and maintaining general health, but it’s the T cell production that really stands out.

#16 Lowers cholesterol and blood pressure

benefits of green tea

When people ask ‘what are the benefits of green tea?’, they’re usually surprised to hear that something as simple as a humble cup of tea can actually decrease their blood pressure and lower their levels of harmful cholesterol. Those are just two of the many benefits of drinking green tea, but they’re incredibly important.

Careful analysis of 20 randomised clinical trials shows a reduction in systolic blood pressure (blood pressure when your heart beats) and an accompanying reduction in harmful LDL cholesterol levels. 

The studies did not find a change large enough to suggest that green tea could be used as a substitute for medication, however the difference was tangible enough to suggest that, when considered alongside all the other benefits on this list, green tea can really help you make a healthy lifestyle change.

Additionally, in another report which analysed 38 studies and experiments, researchers concluded that green tea consumption caused a significant reduction in systolic blood pressure and total and LDL cholesterol.

The bioactive compounds in green tea, along with its antioxidants, are likely responsible for these changes in blood pressure and cholesterol. Similarly, those who consume larger quantities of green tea will find it easier to lose weight, which has the obvious side effect of decreasing blood pressure too. Substituting unhealthy drinks for green tea will yield a positive effect, especially if it's done as part of a wide ranging, healthy diet change.

Another factor which you probably didn't know can aid in lowering blood pressure is outdoor training. You can find out everything you need to know in our full report.

Blood pressure and cholesterol are huge risk factors in many diseases. They're usually the first things that a doctor will look at when advising on lifestyle changes, and they certainly have an effect on longevity, which brings us conveniently on to our final point…

#17 Green tea might even help you live longer 

Green tea benefits for skin

Some green tea health benefits are so profound that they’ve actually been linked to an increased lifespan. This is a dramatic claim, but not one that lacks scientific basis. A vast study involving 100,000 participants from China was tracked for seven years. Over the course of that period, the participants who consumed green tea just 3 times per week were at a dramatically decreased risk of stroke and heart attack.

Moreover, the participants who drank the tea were found to have an increased lifespan, with an extra year added on to their expected longevity. 

The study was observational and so couldn’t prove a definite link between longer life and green tea, but the indicators are certainly favourable. Some of the positive results could be linked to the fact that tea drinkers usually lead healthier lives than non tea drinkers, but the reasons are likely far wider in scope.

Pure green tea benefits are varied. It can help with everything from weight loss to decreasing your susceptibility to cancer and even boost your immune system. A combination of these different factors likely contributes to an increased lifespan. The presence of so many antioxidants helps to decrease free radical presence in the blood, which are linked to premature ageing. 

Studies in this area are ongoing, but there’s no doubt that green tea’s array of individual health benefits are linked to increased longevity. Consuming green tea as part of a healthy and balanced diet, alongside plenty of exercise, is a great way to live longer and feel better.

Green Tea Side Effects

green tea supplement benefits

Now we have detailed the benefits of green tea, you may be wondering what the catch is. Granted, they carry an almost ‘too good to be true’ list of benefits, ranging from aesthetic advantages to health improvements, but all can be supported through scientific findings and results. 

Many of the green tea benefits come from the caffeine and catechins it contains, however they can carry some side effects for some people, especially when consumed in large doses.

By consuming too much caffeine, it can result in the following effects: lead to headaches and in some cases migraines, increase feelings of anxiety, interfere with sleep and cause stomach upset. 

While it is not guaranteed that everyone will encounter these side effects, they are worth noting. Consuming large doses of caffeine is particularly harmful for pregnant women, with research showing that large quantities even increase the risk of birth defects and miscarriage.

Now focusing on the potential side effects caused as a result of the catechins in green tea; it has been suggested through research that they can reduce the body's ability to absorb irons from foods, with evidence even suggesting that consuming large quantities of catechins could in fact lead to an iron deficiency (anemia).

While drinking green tea on a regular basis is not considered a concern for most healthy individuals, those who are at risk of iron deficiency or already have one present should consider drinking tea in between meals as we previously mentioned and waiting at least one hour after eating before drinking green tea. 

It is important to note that the catechins present in green tea can also interfere with certain medications and decrease their effectiveness (this has been proven in treatments for heart and blood pressure, as well as anxiety and depression medication). 

We would recommend consulting with your GP or healthcare professional prior to adding green tea into your lifestyle if you currently take any other medication.

Dosage Recommendations for Green Tea

5 drinking green tea benefits

Based on current research, the daily recommended intake of caffeine should not exceed 300mg a day, this also applies for pregnant women. 

While one report that analysed over 400 studies found that healthy adults who consumed up to 400 mg of caffeine per day did not experience adverse effects, we would still recommend not exceeding the DRI.

The amount of caffeine in one cup of green tea varies depending on the amount of tea used as well as the length of time the leaves are left to steep. A single serving of green tea is usually measured at 1 tablespoon (2 grams) of tea leaves per one cup of water (240 ml) . Assuming this is the measurement for all, it would mean that the average cup of green tea contains approximately 22–40 mg of caffeine.


That concludes our review of the best green tea benefits and side effects and other information you may need if you’re considering whether green tea will advantage your life.

When consumed in moderation, green tea is safe and beneficial for most people. As we have mentioned, if you have an iron deficiency, are pregnant or currently taking medications for conditions such as anxiety, depression or heart problems, then you may want to limit or avoid it, however, aside from that, we believe green tea will only act as a beneficiary to your life. 

Various green tea products and supplements are available to purchase online. We recommend comparing offerings from different brands and the different types of green tea in order to find the most suitable one for you.

Before you head off, has developing your knowledge on nutrition sparked an interest for you? Would you be interested in a career where you can guide others to their fitness goals and support them with nutritional advice? Well you can do this with the Personal Trainer Courses we offer here at OriGym.

Download our latest course prospectus for more information. 


  1. Westerterp-Plantenga MS, Lejeune MP, Kovacs EM. Body weight loss and weight maintenance in relation to habitual caffeine intake and green tea supplementation. Obes Res. 2005 Jul;13(7):1195-204. doi: 10.1038/oby.2005.142. PMID: 16076989.
  2. van Dieren, Susan & Uiterwaal, C & Van der Schouw, Yvonne & van der A, Daphne & Boer, Jolanda & Spijkerman, A & Grobbee, Diederick & Beulens, Joline. (2009). Coffee and tea consumption and risk of type 2 diabetes. Diabetologia. 52. 2561-9. 10.1007/s00125-009-1516-3.
  3. Junhua Li, Rafael Romero-Garcia, John Suckling, Lei Feng. Habitual tea drinking modulates brain efficiency: evidence from brain connectivity evaluation. Aging, 2019; 11 (11): 3876 DOI: 10.18632/aging.102023
  4. Gianeti MD, Mercurio DG, Campos PM. The use of green tea extract in cosmetic formulations: not only an antioxidant active ingredient. Dermatol Ther. 2013 May-Jun;26(3):267-71. doi: 10.1111/j.1529-8019.2013.01552.x. Epub 2013 Mar 13. PMID: 23742288.
  5. Chiu AE, Chan JL, Kern DG, Kohler S, Rehmus WE, Kimball AB. Double-blinded, placebo-controlled trial of green tea extracts in the clinical and histologic appearance of photoaging skin. Dermatol Surg. 2005 Jul;31(7 Pt 2):855-60; discussion 860. doi: 10.1111/j.1524-4725.2005.31731. PMID: 16029678.

Written by Annie Williams

Fitness Content Executive, OriGym

Join Annie on Facebook at the OriGym Facebook Group

Graduating from Liverpool John Moores University with a BA (Hons) in Journalism, Annie specialises in mental and physical wellbeing, with a specific interest in nutrition and mindfulness. Her long standing interest in fitness is what brought her to OriGym, and led her to become a qualified Personal Trainer and obtain specialist qualifications in Advanced Sports Nutrition. Annie’s primary professional attraction lies in following and tracking the ever-changing trends in the fitness industry. Beyond OriGym, Annie divides her time between personal writing, her passion for the countryside and mountain walking, and charitable runs.

Recommended Posts

Download Your FREE 16 Week Muscle Gain Programme


Download Your FREE 16 Week Muscle Gain Programme