What is Green Tea Good For? Energy, Health & Hydration Explained

What is Green Tea Good For? Energy, Health & Hydration Explained

What is Green Tea Good For? Energy, Health & Hydration Explained

Drinking green tea is popular in the health and wellness space. With studies confirming proven health benefits, adding green tea to your diet may seem like a great idea. But how does green tea consumption work? What exactly is it good for?

In this article, we're going to explain what green tea is all about, covering the nutritional make-up of the beverage, potential health benefits, and multiple types of green tea that you can try - including Zest's high caffeine green tea for energy.


Green Tea: What It's All About

Green tea leaves aren't just used to make a healthy beverage to go alongside your chickpea tomato salad. Before we all drank green tea for modern health benefits, it was used as an ancient medicinal herb in areas of the world where the tea plant - Camellia sinensis - grows natively.

Tea is the second most consumed beverage in the world, even beating our love for coffee consumption.1

Green tea, one particular type of tea, can be made from tea leaves grown in China, Japan, India, Taiwan, and numerous other countries that have the right climate for tea agriculture.


How Green Tea is Made

The green tea that's in your tea bag or loose leaf product comes from the same Camellia sinensis bush that creates black tea, white tea, and several other tea types.

To make the green tea, the leaves are harvested and 'fixed' to stop oxidation. This keeps the leaves green and fresh, full of the natural compounds that tea drinkers enjoy. The leaves are dried and packaged, or made into pill form as many green tea extracts are sold.

With little processing, green tea retains the fresh 'greenness' of the tea leaves and tends to have a bright, grassy flavor. Many green teas can be astringent, vegetal and even sweet in flavor too.

To learn more about how green tea is processed, and how it differs to other tea types, read our guide How Is Tea Made? The Production Process Explained.

 growing green tea leaves

Nutritional Value of Green Tea

To make tea, green tea leaves are steeped in water. As a result, green tea will keep you hydrated at the very least. Although caffeine is a mild diuretic, it doesn't dehydrate you.2 You won't lose more water than you consume.

Green tea contains a range of bioactive compounds too. An 8oz serving of green tea may provide:

  • 2 calories
  • 0.5g protein
  • 20mg potassium
  • 2mg magnesium
  • Traces of iron, copper, manganese and zinc3

It's a low calorie beverage with very small amounts of several minerals. The potential health benefits of tea, however, come from a range of other nutrients.


Polyphenols and Antioxidants

Green tea is rich in beneficial polyphenols. These tea polyphenols are natural plant compounds that impact the flavor and mouthfeel of the tea and may also provide nutritional benefits.

Important polyphenols in tea include:

  • Catechins
  • Theaflavins
  • Tannins
  • Flavonoids

Importantly, green tea contains a polyphenol known as epigallocatechin-3-gallate (EGCG). This particular compound is linked to numerous health benefits - read more about these below.

 teapot with loose leaf green tea

Caffeine and L-Theanine

Green tea is a source of caffeine, the stimulant that provides energy by passing the blood-brain barrier and blocking adenosine receptors in your brain. It is also a source of an amino acid known as L-Theanine.

L-Theanine is found in tea leaves and a few rare fungal species. That's it! You don't get L-Theanine in a cup of coffee or any other beverage unless it has been added as a separate ingredient.

L-Theanine also passes through the blood-brain barrier and works in tangent with caffeine. The two compounds interact to slow the onset of caffeine's effects. Separately, L-Theanine promotes alertness, calmness and has unique health benefits particularly for enhancing cognitive function and reducing anxiety.

The combination of caffeine and L-Theanine, along with the antioxidant effects of tea polyphenols, is why green tea is considered by many people to be a very healthy beverage.

Our article L-Theanine Tea explains more about the intriguing properties of the amino acid.


Health Benefits of Green Tea

In summary, green tea has numerous health benefits. Some are proven, others require more research. These five health benefits are among the most well-known. To learn more about the health benefits of tea, read our article A Complete Guide to The Health Benefits of Drinking Tea.


Heart Health

Drinking green tea can result in a reduced risk of numerous cardiovascular diseases. A review of several studies found that drinking green tea reduces some of the risk factors associated with cardiovascular disease: lowering cholesterol (including LDL cholesterol), and lowering high blood pressure.4

Lower blood pressure, controlling cholesterol levels, and losing weight (see below) can all be beneficial for reducing the risk of heart disease and stroke.

 jogger going up steps

Oral Health

Green tea consumption could be good for your dental health. A handful of studies have found that green tea-based mouthwash is effective for reducing plaque.5 Another study has found that green tea improved oral health for patients diagnosed with oral cancer.6

One review hypothesises that this may be due to green tea polyphenols which have anti-viral and anti-inflammatory properties.7

Most studies exploring green tea and oral health apply the green tea topically, rather than through extracts or dietary supplements.


Improve Brain Function

Green tea has an immediate and significant impact on your brain function. Research suggests that caffeine and L-Theanine together increase alertness and reduce tiredness while boosting memory, accuracy and reaction times.8

L-theanine also shows promise for reducing anxiety and could be used, under the guidance of medical expertise, for therapeutic purposes.9


Weight Management

A balanced diet and regular exercise schedule are key to maintain your health and achieve weight loss, if desired. But green tea could be an additional tool to help you lose weight. One study found that green tea has a small impact on the weight loss efforts of overweight and obese adults.10 Another found that caffeine, catechins, and EGCG have a small positive impact on both weight loss and weight management.11

Furthermore, green tea may be able to reduce insulin resistance and blood sugar levels, making it a potential remedy for PCOS and diabetes.12 Of course, more significant research is required to establish a solid link.

One thing that green tea can't do, however, is help your body detox. Learn more about what detoxing entails and how your body does this naturally, without the help of green tea, in our article What is the Best Weight Loss Detox Tea?

 healthy foods

Treat Skin Conditions

Consuming green tea isn't the only way to benefit from the nutritional compounds found in tea leaves. In skincare, green tea (primarily green tea extracts) can have anti-melanogenic, anti-wrinkle, antioxidant, and anti-inflammatory effects.13 As a result, it is often marketed as an anti-aging ingredient.

Green tea may be linked to a lower risk of numerous health conditions through scientific studies, but that doesn't necessarily mean that a cup of green tea can be used to solve all your problems. You should talk to a medical health professional before drinking green tea to treat any symptoms or illnesses!


Different Green Teas and What They're Good For

The many health benefits of green tea are inviting, but the flavor might not be. If you've tried green tea in the past and found it too bitter or dull, you aren't alone. Green tea may be an acquired taste... or maybe you've been drinking the wrong kind of green tea!

Here are five different green teas, each with unique properties and flavors to explore.


Zest Green Tea

zest energy tea in a can

Many people choose black tea over green when it comes to energy, simply because black tea tends to provide more. Both tea types have less than one cup of coffee in terms of caffeine, however.

At Zest, we use green tea extract to boost the levels of caffeine in our tea leaves naturally. As a result, one cup of Zest green tea provides up to 135mg of caffeine and the all-important L-Theanine to create calmness, alertness, and boost all those possible health benefits.

Our green energy tea is available in several flavors, so you don't need to worry about grassy or vegetal notes, as tea bags or loose leaf. You can also try our ready-to-drink green energy tea - we recommend starting with Cucumber Melon.

Addressing the question of what is too much caffeine, the FDA recommends tea drinkers consume no more than 400mg per day. That's equivalent to three cups of Zest Tea, or over 12 cups of regular green tea.


Gunpowder Green Tea

Gunpowder green tea is one of the most widely consumed green tea types. It is made with tightly curled leaves, mimicking the appearance of gunpowder. If you're looking for a plain, simple yet high-quality tea to drink for the health benefits listed above and in medical journals, it's a good choice.


Matcha Tea

matcha tea latte at a desk

Matcha is a type of green tea that's made from powdered, shade-grown tea leaves. This green tea may be extra effective for weight loss and comes with many other associated health benefits, primarily because drinking matcha involves consuming the entire tea leaf.14

Matcha has a strong, fresh and umami flavor that's bordering on savory at times. High quality matcha can also be grassy, sweet and even buttery.



Sencha is a bright green tea from Japan. It has a light, grassy and refreshing flavor, making it an excellent addition to your fresh food diet. Along with a simple citrus salad, it could be a great way to kick-start a clean eating regime.

Sencha is the most popular tea consumed in Japan. Unlike many Chinese teas, sencha is steamed rather than pan-fired during the production process, creating sweeter, grassier and vegetal flavor notes.


Jasmine Green Tea

jasmine flowers

Jasmine green tea may have additional health benefits, besides the benefits that are unique to green teas. The jasmine oils or petals that are infused with this tea are frequently used for aromatherapy and may even be effective for reducing anxiety, for example, for women during the first stage of labor.15

The jasmine gives the tea a light, floral aroma and slightly sweeter, refreshing flavor.


Summary: Green Tea is Versatile

The benefits of green tea, both from brewed tea and green tea extract, stretch from boosting your energy and focus to preventing cardiovascular disease. Combined with a complementary and integrative health plan, it could even be a tool to help you lose weight.

Even with all of these health benefits aside, green tea is a delicious, invigorating and refreshing beverage that's worth drinking for the flavor alone.


Other Tea Types to Consider

The many health benefits of green tea aren't just limited to green tea types. Other tea types have overlapping benefits for your health and provide different flavors to explore.


Black Tea

dried black tea leaves

Also explored for lowering blood pressure and assisting weight loss, black teas are just as popular (if not more ) as green tea in the West. With a bolder, richer flavor and higher caffeine levels, it's also a popular alternative to coffee.

Our high caffeine black teas are best-sellers.


White Tea

White teas are the least processed of all the tea types. With a fresh, mellow flavor, they often have notes of melon or stone fruits. Compared to other tea types, white teas are not so widely consumed and often sold as high-quality or specialty teas.


Oolong Tea

oolong leaf

Oolong teas include a very wide range of flavors, as they can be lightly or heavily oxidized. Likewise, the caffeine content of oolong varies widely. Learn more about what oolong tea entails in our article Oolong Tea In-Depth: Caffeine, Origins, and Types.


Pu-Erh Tea

Finally, pu-erh tea may be a tea type that you want to consider. This fermented tea type has a very acquired taste, with pungent earthy notes. Most commonly found in loose leaf format, packaged into blocks or cakes, it is usually favored by more experienced tea drinkers.



Can you drink green tea on an empty stomach?

Yes, you can drink green tea or take green tea extract on an empty stomach... but it may not be a pleasant experience. Green tea is astringent, mainly due to the tannins in it. These can increase stomach acid content, creating an uncomfortable experience - acid reflux, for example. That's why many expert tea drinkers recommend eating something before or while drinking green tea.

What are the side effects of drinking green tea?

While green tea may come with a lower risk of heart disease and can aid with weight loss, it also has some negative side effects. The tannins in green tea can increase the acid content of your stomach, causing stomach pain and mild digestive problems - these should pass as the tea is digested. Headaches and sleep issues may also be a problem if you are extremely sensitive to caffeine and consume it too close to bedtime.

How much caffeine is in green tea?

Green tea may contain very little caffeine, or quite a lot. How the leaves were grown (e.g. shade-grown or in full sun) as well as the part of the tea plant that's harvested (e.g. tips and buds or lower leaves) can impact the caffeine levels. On average, a cup of green tea contains around 28mg.16 Don't forget that caffeine contributes to some of the health benefits of green tea!

Zest superberry samba green tea

How to make green tea?

Whether you're drinking it for weight loss or enjoyment, the best way to make green tea is to use 80°C/176°F water and let the tea leaves steep for a few minutes. Read our article Best Way to Drink Green Tea to learn more.

When should I drink green tea?

Green tea is best consumed after a meal. Fresh food lines your stomach and prevents the astringency of green tea causing an upset stomach. Green tea also contains a source of caffeine, so you may want to avoid consuming it in the evenings, as it may interfere with your sleep schedule.

Is green tea extract as healthy as drinking green tea?

While many studies into green tea health benefits, from heart disease to blood pressure, may use a green tea extract, that doesn't mean that you should consume the extract too. In high concentrations, the compounds found in green tea could have a strong effect... positive or negative. There have even been a few links to hepatotoxicity.17 On the whole, the FDA and other regulatory bodies aren't too concerned about consuming green tea extract. It's considered pretty safe.

Our advice? Stick to consuming green tea the old fashioned way, and always carefully read the label on any nutritional extract you consume to understand exactly what it contains.

1 https://www.nationalgeographic.com/culture/article/the-worlds-top-drink
2 https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/caffeinated-drinks/faq-20057965
3 https://fdc.nal.usda.gov/fdc-app.html#/food-details/171917/nutrients
4 https://pubmed.ncbi.nlm.nih.gov/23780706/
5 https://pubmed.ncbi.nlm.nih.gov/29652019/
6 https://pubmed.ncbi.nlm.nih.gov/34186380/
7 https://pubmed.ncbi.nlm.nih.gov/22226360/
8 https://pubmed.ncbi.nlm.nih.gov/18006208/
9 https://pubmed.ncbi.nlm.nih.gov/31412272/
10 https://pubmed.ncbi.nlm.nih.gov/23235664/
11 https://pubmed.ncbi.nlm.nih.gov/19597519/
12 https://pubmed.ncbi.nlm.nih.gov/32229652/
13 https://pubmed.ncbi.nlm.nih.gov/26114360/
14 https://pubmed.ncbi.nlm.nih.gov/29345213/
15 https://pubmed.ncbi.nlm.nih.gov/30915314/
16 https://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/in-depth/caffeine/art-20049372
17 https://pubmed.ncbi.nlm.nih.gov/18484782/
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