# Tea (Camellia sinensis)

*Chinese *chá*, Amoy *te*; *thea**

**Known today as.** The dried leaves of *Camellia sinensis*; a ship of the Dutch East India Company brought the first green tea to Amsterdam from China early in the seventeenth century.

Kind: Food & Drink

## What was it used for?

A remedy before it was a pleasure: for headache, drowsiness, the stone, and to help digestion.

## What does modern science say?

Its caffeine is the stimulant; the European Food Safety Authority found too little evidence that theanine improves cognitive function.

## Pharmacognosy and toxicology

- **caffeine**: 30–90 mg a cup
- **L-theanine**: 
- **epigallocatechin gallate**: EGCG, in green tea

**Mechanism.** Caffeine, some 30 to 90 mg a cup, is the stimulant; claims that theanine improves cognition or sleep were not upheld by the European Food Safety Authority in 2011, and the catechins are under study.

**Dose.** Green-tea extracts taken as food supplements at 800 mg EGCG a day or more raised liver enzymes in trials; rare cases of liver injury have followed even the infusion.

**Standing.** A food; in 2018 the European Food Safety Authority found that 800 mg of EGCG a day or more, taken as a supplement, raised markers of liver damage.

## What lore surrounds it?

The Dutch physician Cornelis Bontekoe made his reputation with a treatise advocating tea-drinking, which appeared in 1678.

## What did the older authorities say?

**Thomas Garway.** The London merchant advertised it in a broadside of 1660 as good for nearly every complaint.

## Sources

- Garway, T. (1660). *An Exact Description of the Growth, Quality, and Vertues of the Leaf Tea*.
- Grieve, M. *A Modern Herbal*, “Tea.” As published on botanical.com.
- “History of tea.” *Wikipedia* (read 2 October 2026).
- “Tea.” *Wikipedia* (read 2 October 2026).
- “Theanine.” *Wikipedia* (read 2 October 2026).
- “Cornelis Bontekoe.” *Wikipedia* (read 2 October 2026).
- “Epigallocatechin gallate.” *Wikipedia* (read 2 October 2026).
- Text Creation Partnership. *TCP catalogue* (TCP.csv), github.com/textcreationpartnership.
- European Food Safety Authority (2018). “Scientific opinion on the safety of green tea catechins.” *EFSA Journal* 16.

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*Tea.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-03. The Thinking Press. https://thethinkingpress.org/materia-medica/tea

Historical description, not medical advice.