Chinese Green Tea and Your Health
Green tea is the most popular beverage in China and is increasing in popularity around the world. It is made from leaves of the tea tree (Camellia sinensis) that are steamed or roasted shortly after harvesting to inactivate enzymes, preventing oxidative fermentation, then pressed and finally dried.
Many health practitioners recognise the health benefits of drinking green tea and recommend its consumption to their patients. Similarly, as they did in ancient times, traditional Chinese medicine doctors continue to use green tea as a herb for certain conditions.
Green tea is considered both a food and a natural medicine. While many of us believe drinking green tea is beneficial for health, you might be surprised at what this humble tea can really do for you.
History and culture of green tea
Green tea has been consumed in China for at least 2,000 years. It’s one of the seven ingredients once considered essential for daily life in ancient China, together with firewood, rice, cooking oil, salt, soya sauce and vinegar.
Green tea is not only used as a beverage. In ancient China green tea was also used to clear the mouth, gum and teeth after meals. Ancient Chinese films and books show that green tea was very popular in wealthy families, and often consumed after eating. These films would show the housekeeper bringing the mother and father warm green tea to clean their mouth. They would rinse a few times and spit it out. Then, the remaining tea was drunk to help cleanse their body after a meal.
During the Tang Dynasty the green tea market was thriving and the emperor had defined many regulations for buying and selling tea. Since the 17th century, China has been the world’s ‘home town’ of tea. Nowadays green tea is grown and produced in several other countries as well.
Health benefits of green tea
To date, various potential health benefits of green tea have been scientifically studied including anti-inflammatory, antibacterial, neuroprotective, and cholesterol-lowering effects, which may have an impact on cancer and heart disease risk (Abe & Inoue, 2020). The following health benefits are based on the traditional Chinese medicine understanding of green tea.
Helps to clear Liver Heat and relax the body
Chinese medicine theory states that unflavoured green tea, which is bitter and sweet in taste, has cooling characteristics. As recorded in the Chinese diet therapy textbook of Food and Nutrition, green tea can clear the mind, increase alertness, improve mood and relax your liver, thereby reducing stress. A cup of tea with breakfast or lunch, can improve memory, increase energy and balance emotions for the whole day.
Helps to clear Heat and Toxins from the digestive system and helps bowel movements
Green tea can help to clear food in your digestive system and reduces cholesterol. If you’ve eaten a heavy, rich meal, drink a cup or two of green tea afterwards, to help your body digest oils. Green tea can also be of benefit if you are passing pungent wind, have bad breath, ulcers in the mouth and constipation. These symptoms indicate stagnant toxins or heat in the Large Intestine.
Helps to clear toxins from the body
Daily consumption of green tea can help to flush everyday chemicals such as pollution, alcohol and artificial food additives, from your body.
Helps to clear summer heat
During summer months, we often feel thirsty, have dry skin, get headaches and may experience constipation. These are symptoms associated with too much heat in the body. However, green tea can help cool the body during hot and dry seasons, so it makes sense to add it to your daily diet in summer.
In China, iced green tea or chrysanthemum green tea is a popular drink in summer. You can make this refreshing drink at home simply by refrigerating green tea and adding dried chrysanthemum flowers. You can sweeten the tea by adding a bit of ice sugar, which also has cooling properties. However, avoid using sugar if you have diabetes.
Green tea boosts the immune system
Traditional Chinese medical theory has recommended consuming green tea to prevent disease for over 2,000 years. One of its many benefits is that it clears toxins. And when you reduce toxins in your body, you reduce your risk of disease.
With medical studies confirming that green tea is rich in antioxidants, Chinese medicine and modern science both agree it is beneficial for a healthy immune system.
To increase the immune strengthening properties further, and to increase longevity, try adding one teaspoon of goji berries to the tea. In China, many older people drink this combination.
How to choose green tea
There are various types of green teas from China and other places throughout the world. In the Chinese market, the following green teas are popular: Bi Luo Chun, Long Jing and Tie Guan Yin.
We suggest that before you buy green tea, you can usually visit a quality tea shop to see which one you like. Traditionally, Chinese people are very fussy about their tea and prefer to drink fresh seasonally-picked green tea leaves.
Precautions
While green tea is highly beneficial for overall health, it may not be suitable for everyone, so please keep the following precautions in mind.
- Natural green tea contains caffeine. It is best to avoid drinking it in the late afternoon or evening, as it can affect sleep.
- Children under 12 are advised not to drink strong green tea. They can try mild green tea or avoid it altogether.
- If you are unsure of whether you should drink green tea for your individual health condition, please contact your experienced Chinese medicine practitioner or health professional.
Food as medicine (A disclaimer)
Our “food as medicine” articles share knowledge about health foods in the context of traditional Chinese medicine diet therapy and practices often dating back thousands of years. We also support this knowledge with references to published scientific research. Please keep in mind that scientific research into the health benefits of foods is still emerging and human research is limited.
Consuming a wide variety of natural foods as part of a balanced diet is most beneficial for health, however, we don’t advise using food alone to treat diseases. Please consult with your doctor or health professional about which foods are suitable for your body or health issues.
What Does The Research Say?
The following insights are obtained from scientific studies, systematic reviews and analysis of clinical trials investigating the efficacy of Green Tea.
2020 European Journal of Clinical Nutrition
The literature overall supports an inverse association between green tea and cardiovascular disease-related health outcomes, while the included meta-analyses generally suggested an inverse association between green tea and BMI-related and blood pressure outcomes.
The evidence on green tea consumption and health outcomes presented in this review suggests green tea may be favorable for cardiovascular disease, particularly stroke, and certain cancers such as endometrial, esophageal, lung, non-Hodgkins lymphoma, oral, and ovarian cancer. More evidence is needed to assess the impact of green tea on breast, gastric, and liver cancer risk. Additional studies could also help clarify the suggested null association with certain cancer sites: colorectal, pancreatic, and prostate cancer. Possible minor adverse events on health from green tea consumption were reported in one study, however these must be interpreted cautiously within the study context and possible finer dose-response implications. The findings for green tea and diabetes risk were inconclusive. For BMI the current evidence suggests a possible weak association, while the evidence is stronger supporting a decrease in blood pressure from green tea. More studies investigating a possible association between green tea consumption and other health outcomes such as cognition, injuries, respiratory disease would be informative to more completely assess the impact of green tea on human health.
In conclusion, our review suggests green tea may have health benefits especially for cardiovascular disease and certain cancer sites.
Green tea and cancer and cardiometabolic diseases: a review of the current epidemiological evidence Abe, S.K., Inoue, M.
2019 Aging
Our study offers the first evidence of the positive contribution of tea drinking to brain structure and suggests a protective effect on age-related decline in brain organisation.
Our study comprehensively investigated the effects of tea drinking on brain connectivity at both global and regional scales using multi-modal imaging data (i.e., functional and structural imaging) and provided the first compelling evidence that tea drinking positively contributes to brain structure making network organization more efficient. Our study suggests that tea drinking is effective in preventing (slowing) or ameliorating cognitive decline and that tea drinking might be a simple lifestyle choice that benefits brain health.
Habitual tea drinking modulates brain efficiency: evidence from brain connectivity evaluation Li J, Romero-Garcia R, Suckling J, Feng L.
2018 Beverages
Among the health benefits of green tea are: anticarcinogenic, anti-inflammatory, antimicrobial, and antioxidant properties, and benefits in cardiovascular disease and oral health.
Green tea catechins have proved to be very versatile in providing health benefits. This means that there are potential health benefits for everyone in the consumption of green tea. Even moderate amounts of consumption (drinking 1–2 cups of tea per day) may have benefits. It is a very good thing that it is the second most popular beverage worldwide, as the differences in health in a world without green tea might be significant. There is fortunately a wide variety of research being performed using green tea catechins, and we are starting to see many studies performed using human subjects, as it is extremely important that we are able to show the direct benefits to humans. The expansive repertoire of green tea activity in health is important, especially to those people who live where medical assistance is not generally available or affordable.
An Update on the Health Benefits of Green Tea Wanda C. Reygaert
2017 Phytomedicine
The reviewed studies presented evidence that green tea influences psychopathological symptoms (e.g. reduction of anxiety), cognition (e.g. benefits in memory and attention) and brain function (e.g. activation of working memory seen in functional MRI).
The effects of green tea cannot be attributed to a single constituent of the beverage. This is exemplified in the finding that beneficial green tea effects on cognition are observed under the combined influence of both caffeine and l-theanine, whereas separate administration of either substance was found to have a lesser impact.
Green tea effects on cognition, mood and human brain function: A systematic review Mancini E, Beglinger C, Drewe J, Zanchi D, Lang UE, Borgwardt S
2010 Chinese Medicine
Long-term consumption of tea catechins could be beneficial against high-fat diet-induced obesity and type II diabetes and could reduce the risk of coronary disease.
Laboratory studies showed the health effects of green tea. As the human clinical evidence is still limited, future research needs to define the actual magnitude of health benefits, establishes the safe range of tea consumption associated with these benefits, and elucidates the mechanisms of action. Development of more specific and sensitive methods with more representative models along with the development of good predictive biomarkers will give a better understanding of how green tea interacts with endogenous systems and other exogenous factors. Definitive conclusions concerning the protective effect of green tea have to come from well-designed observational epidemiological studies and intervention trials. The development of biomarkers for green tea consumption, as well as molecular markers for its biological effects, will facilitate future research in this area.
Beneficial effects of green tea: A literature review Chacko, S.M., Thambi, P.T., Kuttan, R. et al.
Scientific References
Browse our collection of scientific research on Green Tea. It includes recent and reputable papers published by peer-reviewed journals within the last 10 years.
2020, Aug 20
Green tea and cancer and cardiometabolic diseases: a review of the current epidemiological evidence
European Journal of Clinical Nutrition
The review highlighted the benefits of green tea for cardiovascular disease, particularly stroke. It also found increased advantages in studies with certain cancers such as endometrial, esophageal, lung, non-Hodgkins lymphoma, oral, and ovarian cancer. Furthermore, green tea is also evident in reducing blood pressure and other cardiovascular diseases.
Abe, S.K., Inoue, M. Full Article
2019, Jun 14
Habitual tea drinking modulates brain efficiency: evidence from brain connectivity evaluation
Aging
Our study comprehensively investigated the effects of tea drinking on brain connectivity at both global and regional scales using multi-modal imaging data (i.e., functional and structural imaging) and provided the first compelling evidence that tea drinking positively contributes to brain structure making network organization more efficient. Our study suggests that tea drinking is effective in preventing (slowing) or ameliorating cognitive decline and that tea drinking might be a simple lifestyle choice that benefits brain health.
Li J, Romero-Garcia R, Suckling J, Feng L. Full Article
2018, Jan 18
An Update on the Health Benefits of Green Tea
Beverages
This systematic review has highlighted the anti-microbial properties, oral health benefits and cardiovascular disease advantages of green tea. Its catechins contain an expansive amount of medical benefits which makes it an affordable healthy beverage
Wanda C. Reygaert Full Article
2017, Oct 15
Green tea effects on cognition, mood and human brain function: A systematic review
Phytomedicine
The reviewed studies indicated that green tea influences psychopathological symptoms (e.g. reduction of anxiety), cognition (e.g. benefits in memory and attention) and brain function (e.g. activation of working memory seen in functional MRI).
Mancini E, Beglinger C, Drewe J, Zanchi D, Lang UE, Borgwardt S Full Article
2010, Apr 6
Beneficial effects of green tea: A literature review
Chinese Medicine International Society for Chinese Medicine
This intensive systematic review showcased that green tea to treat metabolic syndrome for diabetes, contains drug metabolizing enzymes, increased absorption of irons and reduced pro-inflammatory cytokine. However, it also highlights the long term consumptions of green tea with its elevated caffeine levels.
Chacko, S.M., Thambi, P.T., Kuttan, R. et al. Full Article
Rab
Hi there
V interesting website. Is green tea suitable to drink in the peagnancy or would you suggest any other tea which is non caffeine and can help cool down liver and body. And can you plz tell me pepermint comes in which cattagory in food.cool or hot ?
Thanks
Ping Ming Health
Dear Rab, green tea contains high amounts of caffeine so it’s not suitable to drink frequently during pregnancy. A cup here or there is okay. Peppermint tea is cooling in nature. We can also suggest squeezing the juice from a fresh lemon into a glass of room temperature water, drinking this 2-3 times per week is helpful to cool the liver and body.