The Green Fairy, explained (Hint: Think 140 proof)

The ingredient thujone, credited (or blamed, depending on your point of view) with giving absinthe its psychedelic reputation, was apparently overrated. We suspected it, now we have proof. (Get it?) An analysis of old bottles of the stuff has found that they contained relatively small concentrations of thujone, a chemical found in various plants, most notably wormwood.

The drink, a favorite of the late-19th-century bohemian crowd in Paris, was believed to expand the mind, making it a favorite of artists such as Van Gogh, Degas and Picasso. Alas, it was also blamed for violent episodes, illness and "absinthe madness," which was not nearly as much fun as you might think. Symptoms included facial spasms and dementia.

The new analysis, to be published in the May 14 issue of the Journal of Agriculture and Food Chemistry, concluded that the likely culprit in all this was ethanol. Some of the old absinthe was 70% alcohol, making it 140 proof. Gin, vodka and whiskey, by comparison, are usually 80 to 100 proof.

The stuff obviously packed a wallop. Banned for many years in France and elsewhere (including the U.S.), the beverage is making a comeback -- and a couple of brands can even be legally obtained at fine outlets near you. Of course, with a nickname like the Green Fairy and with an entire ritual as part of its preparation, how could it not be popular?

But beware: Though thujone may amount to little more than an exotic-sounding herb, the alcohol itself isn't to be trifled with  -- as anyone who has ever had one too many whiskeys can attest.

-- Tami Dennis

Photo: Carlos Ramos / For The Times

Comments

[J.Bennett]

What nonsense! Thujone degrades over time and this would account for the levels found in +100 year old bottles.

Journal of Agriculture and Food Chemistry should be ashamed of themselves for publishing this rubbish. Thujone is a public health menace, causes epileptic convuslions and of course according to Karin M. Höld, Nilantha S. Sirisoma, and John E. Casida at Berkeley (not an unknown vet from Germany) affects the GABA receptors. They found that the toxin, alpha-thujone, blocks brain receptors for gamma-aminobutyric acid, or GABA. Without access to GABA, a natural inhibitor of nerve impulses, neurons fire too easily and their signaling goes out of control. Wilfred Niels Arnold of the University of Kansas Medical Center in Kansas City also supports this view.

I would be interested to know of any financial arrangement between the publisher and the authors of this absurd conclusory science. I would also like to know if the authors of this paper have any commercial interest in the product.

[David Nathan-Maister]

I'm one of the authors of this paper.

We explicitly dealt with the question of potential thujone degradation in the article. There's an important existing paper on the subject, viz:

"Stability of Pulegone and Thujone in Ethanolic Solution", Fr??lich and Shibamoto (1990)
http://www.thujone.info/thujone-absinthe-40.html

This passage is important:
"No change in the thujone concentrations was noticed during the storage experiments in 100% ethanol and 30% ethanol at either pH 2.5 or pH 6.5. At pH 11.5 a very rapid epimerization of alpha-thujone to the 5 times less toxic beta-thujone (Rice and Wilson, 1976) took place as reported by Hach et al. (1971) and reached an equilibrium of about 1:2 alpha-thujone to beta-thujone after about 20 h. A comparison of the reaction rates at 20"C in sunlight and in the dark showed that the reaction was independent of the influence of light. At the different temperatures (100, 20, and 0 "C), nearly no difference in reaction rate was observed."

What we find in this experiment is the degradation of thujone can be effected via a sufficient pressure of photoirradiation with 310nm UV light (but this is a level way above anything naturally occurring). Under that pressure, thujone undergoes decorbonylation to 5-methylene-6-methyl-hept-2-ene. We of course also made full scan analyses of the pre-ban products. 5-methylene-6-methylhept-2-en was NOT contained in any of the samples.

So not only is there no evidence of any thujone degradation products, but NO degradation at all was observed in real world conditions - ie in the absence of sufficient photoirradiation pressure, despite exposure to sunlight, wide differences in pH, and temperature ranges from 0-100??C.

A further indicator that thujone doesn't deteriorate significantly over time, is the fact that modern absinthes made scrupulously according to Belle Epoque recipes generally have thujone levels in the same range as the pre-ban absinthes we tested - roughly around 20-35mg/l.