Green tea’s health properties have been known for centuries. The relatively recent scientific and public attention on gut health also finds green tea benefits are abundant.
Among other good things, green tea can stimulate the metabolism, improve dental health and hair health, keep away bad bacteria, and may even have some connection with cancer prevention.
This article covers the most important health benefits of green tea, focusing on the gastrointestinal tract, or gut. It also compares the advantages of similar beverages and provides insight into the healthiest varieties, such as matcha and sencha.
As always, we at Enjoy Green Tea want to keep things in perspective and bring the science to back it up.
- Why is gut health important?
- What’s the relation between green tea and gut health?
- What ingredients in green tea support a healthy gut?
- How goes green tea compare with black tea for gut health?
- How goes green tea compare with coffee for gut health?
- What types/varieties of green tea are best for gut health?
Why is gut health important?
The gut plays a key role in our overall health and wellbeing. The food we eat is processed in our gut and into the bloodstream, which delivers all the nutrients throughout our body. The body uses these nutrients for energy, growth, and tissue repair.
“Gut health” describes the function and physical condition of the gastrointestinal tract (gut) and the balance and activity of its “good” and “bad” bacteria.
The intestines also play an important role in the stimulation and normal functioning of the immune system. This is behind our ability to fight diseases and harmful substances.
All these vital processes rely on a healthy gut.
In the past decade, research has also found more evidence that gut health is tied with mental health. So the stomach isn’t just the way to our heart, but also our head!
There are different ways to improve gut health, and green tea is scientifically proven to be one of them.
So while you’re enjoying your ryokucha, mugicha, or matcha, you’re also helping out your innards and, thereby, your whole body. And in low-/no-calorie ways that coffee and sugary smoothies cannot.
What’s the relation between green tea and gut health?
The “alternative health” types will talk about superfoods of the week and healthy trends like gut health. A lot of it is inflated claims and lacks evidence.
But if they’re talking about superfoods of the last few centuries, they’ll be right about green tea.
Here’s why (and the science to prove it).
Green tea positively affects gut health through the following mechanisms.
1. Green tea stimulates growth of “good” gut microorganisms
Gut bacteria play an important role in the digestion process and in the fight against intestinal diseases.
They supply our bodies with essential supplements, produce vitamin K, and promote dietary fiber digestion. Some research suggests that these bacteria can also benefit brain, liver, and heart health, and prevent diabetes by lowering blood sugar levels.
2. Green tea helps prevent growth of “bad” bacteria
Besides the “good” bacteria that contribute to our well-being, there are harmful bacteria that cause a variety of conditions, including inflammation, bloating, abdominal pain, allergies, cancer, and diabetes. (source)
3. Substances in green tea helps regulate many of your body’ systems
For example, catechins stimulate the production of short-chain fatty acids (SCFA). The latter improve the gut health via a number of mechanisms, such as:
- Preventing local inflammation
- Preventing cell damage
- Producing intestinal mucus
- Enhancing local immunity
- Playing some role in prevention of colorectal cancer
What ingredients in green tea support a healthy gut?
Green tea contains many healthy ingredients that benefit both gut and overall health. There’s always more to study, but these are the main ingredients that improve gut health and promote your overall well-being.
Green tea contains vitamins A, B2, B9, C, and E. All of these play an important role in gut health via participation in metabolic processes, preventing oxidative stress, production of collagen, or promotion of local immunity.
Caffeine facilitates digestion by activating bowel movements and stimulating stomach acid production.
Polyphenols, in particular flavanols (also known as catechins), are the main beneficial ingredients in green tea. They make up about 30% of the dry weight of fresh leaves and come in four types: epicatechin, epigallocatechin, epicatechin-3-gallate, and epigallocatechin-3-gallate (EGCG).
The main effects of the most abundant catechin, EGCG, are:
Health-promoting effects of EGCG
- Helps prevent cancer
EGCG is known to be the most abundant catechin in green tea. Research shows that this substance has some association with the prevention of several types of cancer, including breast, lung, prostate, pancreas, head, and neck cancers, as well as colorectal cancers.
- Metabolism of sugar and fat
EGCG can prevent diabetes by suppressing and controlling the rise in blood glucose levels. It also assists in fat oxidation processes, thereby helping to reduce body weight.
- Antioxidant properties
Due to its antioxidant properties, EGCG, together with the vitamins found in green tea, inhibits oxidative damage to the cells lining the intestines.
How goes green tea compare with black tea for gut health?
Both green and black tea are made from the same plant, Camellia sinensis. However, they use different varietals and have different growing, curing, and fermentation processes. For black tea, it makes it lose some of its bioactive elements.
For example, black tea contains less of the most useful component of the tea – polyphenols (catechins). While this makes green tea a healthier option for gut health, black tea drinkers will still somewhat benefit from the health-promoting effects of this beverage.
How goes green tea compare with coffee for gut health?
Like green tea, coffee is rich in polyphenols and caffeine. Caffeine, in particular, is more concentrated in coffee than in tea. This means it has a more profound effect on activating bowel movements; in other words, making you poop. Though among green teas, dripped green tea has a lower concentration than matcha, which is from powdered tea leaves you consume in full.
The concentration of catechins in green tea and coffee is also different, this case in favor of tea. As mentioned, catechins are responsible for most of tea’s health benefits on the gut and its microbiota. They improve the gut microbiota and help prevent colon cancer.
However, the polyphenols in coffee, namely flavonoids and chlorogenic acid, are known for their antioxidant and antidiabetic effects, respectively.
We can’t fairly say one is superior to the other. Just based on drinking experience, people commonly experience more upset stomach from coffee, especially black coffee, than from tea. There may be fewer side effects from tea, though both drinks are beneficial, and delicious. Too much caffeine is also a concern for some, such as pregnant women.
What types/varieties of green tea are best for gut health?
There are several types of green tea, classified based on the fermentation and preparation processes.
The amount of beneficial ingredients differs from type to type, which determines the indications for their use. Among the better-known green teas are:
Sencha tea is what most people think of when they think of green tea. It’s heavily exposed to direct sunlight during cultivation. It then goes through a drying and grinding process.
In Japan, it’s not uncommon to drink it throughout the day. Especially when guests (business or personal) arrive, it’s customary to make tea, and that tea is usually sencha.
Matcha is made from the same plant as regular green tea. This higher-priced and rich tea is used both for ceremonial purposes and casual drinking.
Matcha is made from selected top leaves of tea plants that are specially treated so they are super-packed with chlorophyll, and other ingredients. This gives the characteristic emerald green of the best matcha (and lack of it from the junky non-Japanese matcha; yes, I’m biased).
Those who drink matcha are getting the whole leaf of the plant, rather than the infusion. This can enhance the benefits and packs a little more punch.
Also, the concentration of catechins, one of the healthiest ingredients in green tea, is almost 3 times higher in matcha than in other types of green tea.
Gyokuro is also a variety of the same green tea plant that’s grown in the shade before the harvest and brewed differently. It is the highest grade of green tea and commands a higher price.
This type of green tea is not exposed to direct sunlight, and this concentrates its antioxidant properties. It’s also quite high in caffeine, making it the best energy booster among other green teas.
Gyokyuro combines the standard green tea-ness of sencha with the rich emerald, power-packed properties of matcha. But it’s prepared as a drip/infusion.
*This article was scientifically reviewed by Yeva Margaryan, MD, MPH.