While the green tea craze is starting to catch on worldwide, it has been in existence in Japan, China, and India for centuries. As more people begin to realize why green tea is good for your immune system, it’s only becoming more popular!
Traditionally, the Japanese, Chinese, and Indians utilized green tea in their medicine to boost the immune system and prevent various ailments. It wasn't until recently that the western world discovered green tea and started reaping its health benefits. Aside from just warding off illnesses, green tea has also been proven to help with weight loss, skincare, increasing life expectancy, and even boosting brain function.
(For more on the health benefits of green tea, read this next: 10 Top Health Benefits of Drinking Green Tea.)
Why Is Green Tea Good For Your Immune System?
So, how exactly does green tea help improve your immune system? Let's dig in!
Antioxidant Properties
The secret to green tea’s ability to ward off diseases lies in its antioxidant properties.
While the body produces its own antioxidants (endogenous), on their own, they are not very effective when dealing with free radicals (waste substances resulting from oxidative stress). Oxidative stress has been linked to various ailments—think cancer, arthritis, stroke, heart disease, Parkinson’s disease, and respiratory diseases. When the body is unable to deal with free radicals, it is more susceptible to these conditions. That's why we need external sources of antioxidants (exogenous), which green tea is a good source of!
(For more about cancer and green tea, read this post next.)
Compared to other types of tea, green tea has the highest concentration of polyphenols (antioxidants). This can be attributed to the fact that it is a less processed type of tea. Fresh leaves of Camellia sinensis are rapidly steamed to inactivate enzymes and prevent fermentation and oxidation of essential compounds.
As a result, green tea is rich in polyphenol compounds, known as flavanols or catechins. They include:
- epicatechin
- epigallocatechin
- epicatechin-3-gallate
- epigallocatechin-3-gallate (EGCG).
These flavanols facilitate the immune-boosting properties of green tea.
Cancer Prevention
Another reason green tea is good for your immune system has to do with inflammation.
Many cancer studies have shown a strong link between oxidative stress, chronic inflammation, and cancer. Oxidative stress facilitates the transformation of normal cells into inflammatory or tumor cells. When tumor cells grow uncontrollably, they can lead to cancer. Ultimately, many medical professionals deem inflammation a ‘secret killer’ because, in most cases, it is a precursor to various forms of cancer.
Polyphenol antioxidants in green tea reduce cancer risks by inhibiting or slowing down the oxidative damage process in our bodies. EGCG, in particular, stops cancer cells from growing and even directly kills them.
There are many studies to support the anticancer effects of green tea.
Here are two interesting examples to look at:
- A meta-analysis of studies carried out from 1998 to 2009 showed women who drank green tea had a 30% lower risk of developing breast cancer.
- Another study carried out by the Japan Public Health Center involving more than 49,000 male subjects also showed that green tea reduced the risk of men developing prostate cancer by 48%.
Prevention Of Coronary Heart Diseases
Causes of coronary heart disease include low physical activity and a diet high in saturated fats, which lead to clogging of the arteries (atherosclerosis). Green tea helps prevent coronary heart disease in two ways.
First, it facilitates the proper function of endothelial cells, which prevents atherosclerosis. Inflammation of endothelial cells leads to atherosclerosis.
Secondly, it promotes fat oxidation and prevents obesity.
Also, consumption of green tea reduces the risks of:
- High blood pressure
- Stroke
- Osteoporosis
- Type 2 diabetes
- Liver disease
- Viral diseases
- Bacterial infections
Some studies even find that drinking green tea helps accelerate fitness recovery faster than usual.
UV Protection
Ultraviolet radiation from the sun is linked to various health complications. These include DNA damage, immunosuppression, and skin cancers like melanoma and non-melanoma.
While green tea doesn't block UV rays, it reduces the effects of free radicals and prevents inflammation caused by extensive exposure to sun rays. When green tea metabolizes, the metabolites find their way to the skin tissue fluids. Then, they form a kind of protective shield against the effects of UV rays.
A study showed that people who took small oral doses of green tea (two cups for 12 weeks) experienced less reddening of the skin (erythema) when exposed to sun rays than those who did not.
In another study, mice that were administered green tea through water showed fewer tumor incidences in terms of size and multiplicity compared to mice that were not. Since tumors are directly linked to cancer, reducing tumor incidence also reduces the cancer risk in many cases. And finally, the anti-inflammatory effects of green tea also slow down the process of aging.
Antimicrobial Properties
Several studies have also shown that green tea has antimicrobial properties that inhibit the growth of bacteria and viruses. Two particular polyphenol catechins, epigallocatechingallate (EGCG) and epicatechingallate (ECG), can suppress the activities of bacterial and viral factors. They can even reverse the resistance of formidable pathogens, such as methicillin-resistant Staphylococcus aureus (MRSA). ECG and EGCG have the ability to penetrate through phospholipid layers.
As a result, these two catechins alter bacteria and viruses’ functions by disrupting their cytoplasmic membrane, making them vulnerable to antibiotics. Evidence suggests that the two catechin molecules can help effectively control various oral infections, such as dental caries, periodontal disease, tooth decay, and bad breath.
The benefits of green tea are numerous. Some studies even indicate that green tea improves brain function. It may even lower your risk of Alzheimer’s and Parkinson’s diseases in old age.
Another quality that makes this beverage stand out? It can be consumed or ingested in various ways—not just through sipping! You can use it to dress salads, dunk rice (ochazuke), include it in your smoothie, or even use it to prepare a marinade. The choices are innumerable, and you can use it in virtually any type of food.
And don't forget: there are so many types of green tea brands, each with different flavors and health benefits you can take advantage of. So, don't limit yourself to just a single brand and deny yourself the benefits of others! Enjoy as many brands as possible to boost your immune system and keep your body in good shape.
How to brew a perfect immune-boosting green tea
You should know that tea is most effective when appropriately brewed. It is the same case with green tea. To get the best of it, you need to prepare it with proper steps and right ingredients. Nowadays, you will see tea bags which are easy to use, and you can carry with you everywhere. However, loose leaf boxes are more eco-friendly as the tea wrappers are not recyclable and add waste to already pilling waste on Earth. But check for the brand and contents before buying. It would be best if you try different brand varieties to get the best of them.
For preparing green tea use filtered water and avoid tap or mineral water for brewing. Pour it into a pot and bring it to boil. For the best effect, use just-below-the-boiling water. Pour it into your ceramic cup. You can use a tea bag or loose leaf as per your choice. For the maximum benefits and less bitterness, steep the leaves for a minute or two. Remove the tea bag or leaves and stir your tea.
You can add a teaspoon of honey and half a lemon for added benefit, and it also blunts the extra bitterness. It enhances your tea and increases your metabolism, digestion and immune system.
Avoid adding milk in it. The protein in milk binds to the polyphenols and makes them ineffective. This ingredient, along with others, are the main source of your healthy immune system and adding milk just makes it ineffective to your health.
However, matcha green tea is the most effective as you drink whole leaves content and gives you energy. Match has a little different procedure. Pour lukewarm water and teaspoon matcha powder in a bowl and whisk it with a bamboo whisk. Do it until it becomes smooth and frothy. You can either drink it hot or cold with ice. Matcha has intense sweetness and less bitterness. Some add milk to lessen the effect, and it has vertstaile use as some add into their food as a flavour. Either way, it is most effective and helps you build your immune system faster and keeps you refreshed all day.
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About the author
Kei Nishida
Author, CEO Dream of Japan
Certification: PMP, BS in Computer Science
Education: Western Washington University
Kei Nishida is a passionate Japanese green tea connoisseur, writer, and the founder and CEO of Japanese Green Tea Co., a Dream of Japan Company.
Driven by a deep desire to share the rich flavors of his homeland, he established the only company that sources premium tea grown in nutrient-rich sugarcane soil—earning multiple Global Tea Champion awards.
Expanding his mission of introducing Japan’s finest to the world, Kei pioneered the launch of the first-ever Sumiyaki charcoal-roasted coffee through Japanese Coffee Co. He also brought the artistry of traditional Japanese craftsmanship to the global market by making katana-style handmade knives—crafted by a renowned katana maker—available outside Japan for the first time through Japanese Knife Co.
Kei’s journey continues as he uncovers and shares Japan’s hidden treasures with the world.
Learn more about Kei
No doubt, Green tea play an important role in developing the immune system. Thanks for the information shared.
This is a really very informative article! Soothing green tea must be a definite choice for any tea lover. In addition to its amazing taste, it helps to improve immune system. Thanks for sharing!