Green Tea

At a Glance

Common name

Green Tea

Scientific name

Camellia sinensis

Family

Theaceae

Region

East Asia

Plant part

Leaves (and leaf buds)

Caffeine

Caffeinated (moderate, ~20–45 mg/cup)

Evidence

Moderate

Safety review

Safety information on file

Botanical Description

An evergreen shrub or small tree 1–9 m, pruned low for plucking, with glossy dark green serrated leaves, white fragrant five-petaled flowers, and a tender leaf bud (the tip). Green tea is made from leaves that are quickly heated/steamed to prevent oxidation.

Also known as: Tea Plant, Tea

Historical Background

Tea is the world's most consumed manufactured beverage after water, with 5,000 years of history in China — first as a medicine, then as a drink. Green tea (unoxidized) preserves more catechins than black tea, and its long association with meditation (Zen/Chan) and health spans Chinese, Japanese, and global cultures.

Earliest recorded uses: Chinese legend attributes tea's discovery to Shennong (~2737 BCE); Lu Yu's Classic of Tea (760 CE) codified it.

Cultural significance: Tea shaped Chinese and Japanese civilization — the Japanese tea ceremony (chanoyu) is a Zen-inspired art of attention and hospitality, and the word 'tea' now denotes both the plant and the global ritual of brewing.

Traditional Uses

These uses document historical traditions and do not imply proven effectiveness.

Flavor & Aroma

Aroma: Fresh, grassy, vegetal, sometimes marine

Tea Preparation

Modern Evidence

Green tea is among the most-studied beverages; its catechins (notably EGCG) have antioxidant and mild metabolic effects. Some trials suggest modest benefits for cardiovascular risk markers and alertness, while evidence for cancer prevention is inconclusive. Concentrated extracts have been linked to rare liver injury. It is a caffeinated beverage, not a medicine.

Evidence levels describe the state of research for the traditional use discussed here, not a recommendation. Historical use does not imply effectiveness.