hist-brewing: Tansy in Ale
bjm10 at cornell.edu
Wed Mar 6 10:16:58 PST 2002
>Tansy can be very dangerous in anything more than small amounts,
>especially for pregnant women. Don't do it.
To give more detail to this warning:
There is more than one "Tansy".
_Tanacetum vulgare_ (_Chrysanthemum vulgare_) is "common tansy". Its
main "essential oil" is the terpenoid ketone thujone--yes, the active
ingredient in wormwood. Death has been known from taking common
tansy in "medicinal" doses. "Oil of tansy" is roughly 50% thujones,
according to the WHO. For dogs, LD50 occurred at 250mg/kg (oral
administration). However, it should be noted that Purdue University
classifies the plant in the same category as it does common burdock,
english ivy, and catnip. Paulsen et al (1993), reported roughly 5%
of test population having allergic reaction (topical) to tansy.
There is also "Tansy ragwort" (_Senecio jacobaea_). Tansy ragwort is
considered to be a threat to grazing livestock, able to keep its
toxicity even after being cut and dried along with desired plants for
use in hay. Its dose of alkaloid toxins can kill over a long period
of time, since the liver damage it causes can be cumulative. The
USDA lists it as a noxious weed, and since it's of foreign origin,
its eradication in the USA would be legal (and highly approved of).
But even if one has a-hold of the "good" tansy, note that there are risks.
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