Camellia sinensis Green Tea: Herbal Monograph
Camellia sinensis green tea is the cooling, drying leaf of the tea plant. This herbal monograph sets out its botany, energetics, constituents, traditional uses and cautions, with references.
Family
Theaceae
Actions
Antioxidant, thermogenic, diuretic, astringent, mild stimulant (Chacko et al., 2010)
Energetics
Cooling, drying (Tierra, 1998)
Chemical Constituents
- Catechins (Epigallocatechin gallate (EGCG), Epicatechin gallate (ECG), Epigallocatechin (EGC), Epicatechin (EC))
- Caffeine
- Theanine
- Flavonoids (quercetin, kaempferol, myricetin)
- Vitamins (C, B2, E)
- Minerals (zinc, selenium, chromium, manganese)
The polyphenolic compounds, particularly catechins, are responsible for many of green tea‘s biological activities (Khan & Mukhtar, 2019).
Part of Plant Used
Leaves (fresh or dried)
Uses
- Supports cognitive function
- Promotes cardiovascular health
- Supports healthy weight management
- Promotes oral health
- Supports healthy inflammatory response
- Promotes antioxidant activity
A comprehensive review by Xing et al. (2019) highlighted green tea‘s potential in supporting various aspects of health, particularly in cardiovascular and metabolic wellness.
Contraindications
- Iron deficiency anemia (may impair iron absorption)
- Anxiety disorders (due to caffeine content)
- Bleeding disorders
- Liver disease
Side Effects
- Potential for sleep disturbances due to caffeine content
- Possible gastrointestinal discomfort in some individuals
- May cause mild headaches in sensitive individuals
While generally well-tolerated, these side effects have been noted, particularly with high consumption (Yoto et al., 2014).
Interactions with Other Drugs
- May interact with anticoagulant preparations
- May affect iron absorption
- May interact with certain stimulant preparations
- May interact with certain chemotherapy drugs
Caution is advised when combining green tea with these types of preparations due to potential interactions (Ide et al., 2016).
Dosage
- Brewed tea: 3-5 cups daily (containing approximately 200-500 mg of polyphenols)
- Green tea extract: 250-500 mg daily (standardized to 50% polyphenols)
Clinical studies have used a wide range of doses, typically 200-1500 mg of green tea catechins daily for various applications (Ohishi et al., 2016).
Mode of Administration
Oral consumption as brewed tea, extract, or capsules.
Duration of Administration
Can be consumed daily as a beverage. For high-dose extracts, consult with a qualified herbalist for long-term use.
Risks
- Potential for caffeine-related side effects with high consumption
- Rare cases of liver toxicity reported with concentrated extracts
- May affect iron absorption with excessive consumption
A review by Hu et al. (2018) emphasized the importance of considering individual health conditions and potential interactions when using green tea therapeutically.
Recipes
- Classic Green Tea
- 1 teaspoon green tea leaves
- 8 oz water at 175°F (80°C)
Steep for 2-3 minutes, strain, and enjoy.
- Green Tea Latte
- 1 teaspoon matcha green tea powder
- 1 cup steamed milk (dairy or plant-based)
- Honey to taste (optional)
Whisk matcha with a small amount of hot water, add steamed milk and honey if desired.
- Iced Green Tea
- 4 green tea bags
- 4 cups cold water
Steep tea bags in cold water for 6-8 hours in the refrigerator, remove bags, and serve over ice.
Brewing for Physic
- Water and time: keep the water below boiling, about 70–80 °C, and steep for 1–3 minutes. Boiling water and long steeping turn the tea harsh and bitter.
- Drink the whole leaf. The Japanese drink matcha as a whisked suspension, so they swallow all of the tea. I encourage you to grind your tea blends fine, sometimes twice, and drink the sludge at the bottom of the cup. Your microbiome will take it as a small gift of fibre — a micro-salad.
- A squeeze of lemon helps protect the catechins through digestion (Green et al., 2007).
- Timing: drink green tea between meals rather than with them. The tannins reduce iron absorption, especially iron from plants.
- Caffeine: a cup holds roughly a third of the caffeine in a cup of coffee. The theanine in tea softens its edge, but sensitive sleepers should still stop by mid-afternoon.
Remember to always consult with a qualified herbalist before incorporating new herbs into your wellness routine, especially if you have existing health concerns or are taking other preparations.
Return to: A Wise Woman’s Guide to Reducing Inflammation with Herbs, Foods, and Lifestyle
© 2024 Carolyn Smith-Kizer
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References
Chacko, S. M., Thambi, P. T., Kuttan, R., & Nishigaki, I. (2010). Beneficial effects of green tea: A literature review. Chinese Medicine, 5, 13. https://doi.org/10.1186/1749-8546-5-13
Green, R. J., Murphy, A. S., Schulz, B., Watkins, B. A., & Ferruzzi, M. G. (2007). Common tea formulations modulate in vitro digestive recovery of green tea catechins. Molecular Nutrition & Food Research, 51(9), 1152–1162. https://doi.org/10.1002/mnfr.200700086
Hu, J., Webster, D., Cao, J., & Shao, A. (2018). The safety of green tea and green tea extract consumption in adults – Results of a systematic review. Regulatory Toxicology and Pharmacology, 95, 412-433. https://doi.org/10.1016/j.yrtph.2018.03.019
Ide, K., Yamada, H., Kawasaki, Y., Noguchi, M., Kitagawa, M., Chiba, T., Kagawa, Y., & Umegaki, K. (2016). Green tea consumption affects cognitive dysfunction in the elderly: a pilot study. Nutrients, 8(5), 256. https://doi.org/10.3390/nu8050256
Khan, N., & Mukhtar, H. (2019). Tea polyphenols in promotion of human health. Nutrients, 11(1), 39. https://doi.org/10.3390/nu11010039
Ohishi, T., Goto, S., Monira, P., Isemura, M., & Nakamura, Y. (2016). Anti-inflammatory action of green tea. Anti-Inflammatory & Anti-Allergy Agents in Medicinal Chemistry, 15(2), 74-90. https://doi.org/10.2174/1871523015666160915154443
Tierra, M. (1998). The way of herbs. Pocket Books.
Xing, L., Zhang, H., Qi, R., Tsao, R., & Mine, Y. (2019). Recent advances in the understanding of the health benefits and molecular mechanisms associated with green tea polyphenols. Journal of Agricultural and Food Chemistry, 67(4), 1029-1043. https://doi.org/10.1021/acs.jafc.8b06146
Yoto, A., Motoki, M., Murao, S., & Yokogoshi, H. (2014). Effects of L-theanine or caffeine intake on changes in blood pressure under physical and psychological stresses. Journal of Physiological Anthropology, 31(1), 28. https://doi.org/10.1186/1880-6805-31-28