Green Tea (Camellia sinensis Kuntze)

What is Green Tea?

Green tea is made from the unoxidized leaves of Camellia sinensis — an evergreen shrub or small tree with glossy, serrated leaves and fragrant white flowers. Unlike black or oolong tea, green tea leaves are minimally processed, retaining high levels of natural antioxidants. Renowned for its antioxidant, metabolic and cognitive health benefits, green tea has been central to traditional Asian medicine and modern wellness culture alike — from heart and brain health to detox and weight management.

In Ayurveda, green tea is considered Pitta-pacifying due to its cooling, slightly bitter and astringent nature. In Traditional Chinese Medicine it has long been valued as a daily tonic for clarity, vitality and balance.

Where Does It Grow?

Green tea is native to South and Southeast Asia and is now cultivated in over 30 countries. Cooler temperatures and misty highlands yield higher-quality leaves rich in catechins and volatile oils.

Geographical Distribution

• South and Southeast Asia — India, China and Myanmar
• Japan — a centre of premium green and matcha tea cultivation
• Korea — traditional highland tea-growing regions

Ideal Growing Conditions

• Altitude — higher elevations and misty highlands produce the finest leaves
• Climate — cooler temperatures yield leaves richer in catechins and volatile oils
• Soil — rich, slightly acidic, well-drained loamy soils
• Rainfall — consistent moisture supports tender new growth

Parts Used & Key Phytochemicals

The young leaves and buds are the primary parts harvested and processed for medicinal use. Green tea is rich in a unique profile of bioactive compounds:

• Catechins (EGCG, EGC, ECG, EC) — powerful polyphenolic antioxidants
• Theanine — a calming amino acid that enhances cognitive function
• Caffeine — provides mild central nervous system stimulation
• Flavonoids and tannins
• Vitamins (C, B complex) and minerals (zinc, selenium)

Among these, EGCG (epigallocatechin gallate) is the most researched catechin, with well-documented effects on metabolism, a healthy inflammatory response and cellular protection. Green tea is also valued within Medhya Rasayana traditions prized for cognitive vitality and clarity.

Functional Benefits of Green Tea

Green tea offers a wide spectrum of health benefits ranging from antioxidant support and metabolism enhancement to neuroprotection and cardiovascular health.

Antioxidant support & a healthy inflammatory response

• Scavenges free radicals and protects cells from oxidative stress
• Supports a healthy inflammatory response throughout the body
• Delays cellular aging and supports natural detoxification

Cognitive & neuroprotective

• The combination of L-theanine and caffeine improves focus without overstimulation
• Protects neurons from degeneration, supporting cognitive longevity
• Studied for supporting attention and memory in older adults

Metabolic & cardiovascular

• Supports healthy LDL and HDL levels already within the normal range
• Supports healthy weight management alongside diet and exercise
• Supports healthy blood sugar levels already within the normal range and insulin sensitivity

Digestive, liver & skin support

• Traditionally used to ease occasional digestive discomfort
• Supports liver health, normal liver function and a healthy inflammatory response
• Improves skin tone and appearance, and helps protect the skin against UV damage

How to Use Green Tea Safely

Green tea can be consumed as a beverage or taken in concentrated extract form. Its versatility makes it suitable for daily consumption in moderate amounts. Whether enjoyed as a warm cup of tea, a concentrated capsule or a rejuvenating matcha, green tea is a daily ritual with science-backed benefits for body and mind — best consumed with mindfulness and balance.

Forms Available

• Loose-leaf and brewed tea
• Matcha — finely ground whole-leaf powder
• Standardized green tea extract in capsules and tablets
• Green tea extract in functional foods, cosmetics and supplements

Research Highlights

Green tea is one of the most widely studied botanicals in scientific literature, with extensive research across multiple domains.

• Cardiovascular — a 2020 meta-analysis found that green tea intake supports healthy blood pressure and LDL levels already within the normal range.
• Weight management — clinical trials support its role in enhancing fat metabolism and healthy weight management alongside diet and exercise.
• Cognitive function — L-theanine and EGCG improve attention and working memory in human studies.
• Antioxidant protection — EGCG has been shown to limit oxidative stress in cells in preclinical studies.

Green tea is recognized by EFSA, NIH and WHO for its functional food and nutraceutical value.

Precautions & Contraindications

Green tea is generally safe when consumed in moderation, but certain considerations are necessary.

• Pregnancy and breastfeeding — limit to 1–2 cups per day due to caffeine
• Iron-deficiency anemia — tannins can reduce iron absorption; avoid taking with meals
• Stimulant sensitivity — caffeine may disturb sleep or cause palpitations in sensitive individuals
• Medications — may interact with blood thinners, stimulants and beta-blockers
• Liver — excessive extract consumption has been associated with liver toxicity

References

1. Hodgson, J. M., Croft, K. D., et al. (2012). Tea flavonoids and cardiovascular health. Molecular Aspects of Medicine, 31(6), 495–502.
2. Kao, Y. H., Hiipakka, R. A., Liao, S. (2000). Modulation of endocrine systems and food intake by green tea epigallocatechin gallate. Endocrinology, 141(3), 980–987.
3. Park, S. K., et al. (2014). JAMA, 296(10), 1255–1265.
4. Scholey, A. B., et al. (2012). Effects of green tea and L-theanine on brain function. Nutrients, 4(10), 1631–1644.
5. Cabrera, C., Artacho, R., Giménez, R. (2006). Beneficial effects of green tea — A review. Journal of the American College of Nutrition, 25(2), 79–99.