Tea

[Guest guest]

Hi All,

This was about the only thing I thought of potential interest in today's

Lancet.

Four liters is a lot of tea.

Cheers, Al.

Lancer Correspondence

“Tea: not immoral, illegal, or fattening, but is it innocuous?

Sir--J Finsterer's report (April 27, p 1484)1 of intoxication with Earl

Grey tea coincides with a report on tea intoxication in the Netherlands

involving 63 people, of whom 22 needed admission.2

In Finsterer's case, the toxic component was bergapten contained in the

bergamot oil flavouring. The tea was consumed in large quantities of up to 4

L daily, and led to symptoms of muscle cramps, paraesthesiae, and blurred

vision after 1 week. He deems the mechanism to be due to a largely selective

axolemmal potassium-channel blocker, reducing potassium permeability at the

nodes of Ranvier.

In the Netherlands report, herbal tea probably contained the Japanese star

anise (Illicium anisatum L) instead of the Chinese star anise (Illicium

verum L). The Japanese star anise contains anisatin, which is a

non-competitive GABAA-receptor antagonist. In in-vitro studies, anisatin may

cause long-term inhibition of the response to GABA once the receptor is

blocked. The reported patients developed nausea, vomiting, auditory

hallucinations, and epileptic attacks within hours of ingestion.

More than 3 billion kg of tea made from the leaves of the plant Camellia

sinenis is consumed worldwide yearly, and has been drunk since at least 2737

BC. Of this, 78% is black tea, most of which is consumed in European

countries and the USA. The leaves are allowed to wither before being broken

to allow oxidisation or fermentation. Green tea, for which the withered

leaves are steamed and rolled before drying to stop fermentation, accounts

for 20% of consumption and is commonly drunk in Asian countries. The other

2% of consumption is of Oolong tea, produced by partial fermentation and

consumed mainly in Southern China.

More than 2000 varieties of tea are produced, including spiced and

flavoured varieties. Tea from the leaves of the plant Camellia sinenis has

been associated with some health benefits attributed to its antioxidant

activity.3 However, toxicity has been extensively reported in components of

herbal teas containing such diverse ingredients as fir club moss, angel's

trumpet, nerium oleander, mabi bark, and foxglove.

Tea is a comfort without which normal daily life for many would be much

more stressful.

Finsterer's and the Netherlands' cases destroy our life-long belief that

tea is one little pleasure that, to quote Woollcott is not

" immoral, illegal or fattening " .4

Anne Marie Oudesluys-, Niall Oudesluys

1 Finsterer J. Earl Grey tea intoxication. Lancet 2002; 359: 1484.

2 Johanns ESD, van der Kolk LE, van Gemert HMA, Sijben AEJ, s PWJ, de

Vries I. An epidemic of epileptic seizures after consumption of herbal tea.

Ned Tijdschr Geneeskd 2002; 146: 813-16. [PubMed]

3 Yang CS, Landau JM. Effects of tea consumption on nutrition and health.

J Nutr 2000; 130: 2409-12. [PubMed]

4 Drennan RE (ed). The Algonquin wits. Secaucas: Citadel, 1968.”

Alan Pater, Ph.D.; Faculty of Medicine; Memorial University; St. 's, NF

A1B 3V6 Canada; Tel. No.: (709) 777-6488; Fax No.: (709) 777-7010; email:

apater@...