Green tea extract improves gut health and glucose levels

A study published in June 2022 put forward the idea that green tea extract – which is rich in catechins – may reduce intestinal inflammation and lower fasting glucose levels in adults.

Written by Joanna Hodges, et al, the study – “Catechin-Rich Green Tea Extract Reduced Intestinal Inflammation and Fasting Glucose in Metabolic Syndrome and Healthy Adults: A Randomized, Controlled, Crossover Trial” – tested whether green tea extract (GTE) would help alleviate intestinal inflammation. They also noted a link with fasting glucose levels.

So – how does green tea improve gut health and glucose levels?

Catechins in green tea

Green tea consists of leaves from the Camellia sinensis plant, which proliferates mainly in Asia. It has several potential health benefits due to its high concentration of antioxidants and polyphenols.

Recently, however, research has begun emerging about green tea’s antimicrobial properties, the important components of which are catechins.

Catechins are flavonoids and comprise 80–90% of flavonoids in green tea. This type of tea contains a higher concentration of catechins than other forms of tea due to the way it is processed. Green tea is produced from mature tea leaves left unfermented – resulting in a potent amount of flavonoids and chlorophyll.

Green tea has four main types of catechins – EC, EGC, ECG, and EGCG. Of the four, EGCG is the most abundant and has been the subject of much research.

The flavonoids – and therefore catechins – in green tea positively influence our health. They have anticarcinogenic, anti-inflammatory, antioxidant, and antimicrobial properties.

This means they can help prevent and mitigate conditions such as cardiovascular disease, diabetes, obesity, and neurological disease.

In particular, green tea and catechins can help [1]:

  • Boost the creation of anti-inflammatory cytokines
  • Increase activity of antioxidant enzymes
  • Reduce bad cholesterol
  • Stimulate insulin secretion
  • Inhibit absorption of fat
  • Improve oral health

And now, new research has shown that green tea can improve a person’s gut health by reducing intestinal inflammation. It can also lead to a lower fasting glucose level.

Catechins in green tea

The study by Joanna Hodges, et al, [2] determined that green tea extract (GTE) could reduce intestinal inflammation due to its high concentration of catechins. It noted that pre-clinical evidence showed GTE improved gut barrier function and reduced intestinal inflammation.

The methodology of the study involved having participants consume either placebo gummies or GTE gummies that contained the equivalent of 5 cups of green tea for 28 days. Researchers then tested fecal and urine samples to measure inflammation and glucose levels.

Participants of the study followed a low-polyphenol diet to ensure no other polyphenol-rich food could interfere with results. Researchers also conducted the study in a randomized, double-blind, and placebo-controlled manner.

At day 0, day 14 and day 28 of the trial, they measured dietary polyphenols, fasting blood glucose, and insulin levels.

The study included both healthy persons and those who had metabolic syndrome (a group of conditions including high blood pressure, high blood sugar, and abnormal cholesterol levels).

Fasting insulin remained unaffected by an intake of green tea extract, but fasting glucose decreased. Intestinal inflammation also saw a decrease in those with GTE-enriched diets. These results were consistent regardless of health status.

There are also related studies by Sergio Pérez-Burillo, et al [3] and Eun Sung Jung, et al [4] that study the effects of green tea supplementation on the human gut microbiome.

These studies showed that green tea stimulated the growth of beneficial bacteria and hindered the growth of detrimental ones.

What else is green tea good for?

Green tea has plenty of other health benefits besides improving gut health and blood glucose levels. It is rich in antioxidants, which combat oxidative stress in our bodies.

Oxidative stress occurs due to an excess level of free radicals, which damage cells and play a key role in age-related degenerative conditions such as cancer.

Green tea also benefits our cardiovascular health – it can lower blood pressure and cholesterol levels while reducing the risk of developing detrimental cardiovascular conditions.

Some research has even shown that consuming 5 cups of green tea in a day lowers the mortality risk from a cardiovascular condition [5].

Moreover, green tea extract has been studied for its potential role in weight management and metabolic health. Research suggests that the catechins in green tea may enhance fat oxidation and thermogenesis, thereby aiding in weight loss and maintenance.

Additionally, green tea extract may help regulate lipid metabolism, leading to improvements in cholesterol levels.

The caffeine in green tea stimulates the brain, allowing you to feel more alert and focused. The bioactive compounds in green tea might also enhance the performance of a person’s memory and thinking.

Beyond its metabolic benefits, green tea extract exhibits anti-inflammatory properties, which can help alleviate inflammation throughout the body.

Chronic inflammation is linked to various health conditions, including cardiovascular disease, arthritis, and neurodegenerative disorders. By reducing inflammation, green tea extract may contribute to preventing and managing these conditions, promoting long-term health.

Emerging research indicates that green tea extract possesses anti-cancer properties, attributed to its ability to inhibit tumor growth and metastasis. While more studies are needed to fully elucidate its mechanisms and efficacy in cancer prevention and treatment, preliminary findings are promising and warrant further investigation.

Should you drink more green tea for gut health and glucose control?

Green tea is an overall healthy drink and clearly has a beneficial place in our diets. However, you should always consult a registered dietitian before consuming green tea extract as supplements or adding large quantities of green tea to your daily beverage intake.

Still, there’s no harm in drinking a few cups of brewed green tea every day – not only is it good for you, but it’s tasty!

Drinking green tea for health

Drinking green tea for health

The catechins in green tea have several studied health benefits, including improving the conditions of our digestive systems and reducing glucose levels in the blood. They reduce inflammation in the gut, as well, and potentially stimulate the growth of healthy bacteria in our stomachs.

While we shouldn’t be jumping to consuming 10 cups of green tea in a day, drinking a cup or three can help improve our overall health. You’ll boost your cognitive, cardiovascular and digestive function as well as potentially prevent skin cancer.

Just remember to drink plain green tea or matcha – eating pastries or drinking bubble tea will have the opposite effect!

How do you use green tea extract?

Incorporating green tea extract into your daily routine can be a straightforward and enjoyable process. Whether you prefer supplementation or enjoy a soothing cup of brewed green tea, there are various ways to reap the benefits of this potent botanical extract.

Firstly, when considering supplementation, it’s crucial to choose high-quality products from reputable brands. Look for standardized extracts with a high concentration of active compounds, such as EGCG.

Start with a low dosage and gradually increase as tolerated, following the manufacturer’s recommendations. Additionally, consider consulting with a healthcare professional to ensure the supplement is suitable for your individual health needs and goals.

Alternatively, you can enjoy the health benefits of green tea extract by incorporating brewed green tea into your daily routine. Opt for high-quality loose-leaf or bagged green tea for the best flavor and nutrient content.

To brew green tea, simply steep one teaspoon of tea leaves or one tea bag in hot water (not boiling) for 2-3 minutes to avoid bitterness. You can adjust the steeping time based on your preference for a milder or stronger flavor.

For added versatility, try incorporating green tea extract into your favorite recipes. You can infuse baked goods, smoothies, or even savory dishes with the subtle flavor and health benefits of green tea.

Experiment with different culinary creations to find delicious ways to incorporate green tea extract into your diet.

Lastly, remember to enjoy green tea extract as part of a balanced and varied diet. While it offers numerous health benefits, consuming it in moderation and alongside a diverse range of nutrient-rich foods is essential.

By incorporating green tea extract into your routine thoughtfully and consistently, you can harness its powerful properties to support your overall health and well-being for years to come.

In closing

A growing body of scientific research supports the benefits of green tea extract for gut health and glucose regulation. Not only does green tea extract improve gut microbiota composition, but it also aids in regulating glucose levels and insulin sensitivity.

Additionally, green tea extract offers a range of other health benefits, including antioxidant, anti-inflammatory, and potential anti-cancer properties.

Incorporating green tea extract into your daily routine can be a simple yet effective way to support your overall health and well-being.

As we strive to maintain optimal health, let us remember the power of nature’s remedies, such as green tea extract, to enhance our wellness journey. By embracing the holistic benefits of green tea extract and incorporating it into our lifestyle, we can take proactive steps towards achieving long-term health and vitality.


Photograph: Deenida/Shutterstock
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