General misconceptions about the wormwood-flavoured spirit absinthe
"During our research on absinthe, we discovered that there is a general misunderstanding amongst the public, as well as in the scientific community, about the properties of absinthe in general, and the thujone content in particular. It is remarkable that, even in peer-reviewed journals, unsubstantiated myths and legends are continually repeated."
Chemisches und Veterinäruntersuchungsamt (CVUA) Karlsruhe, Weißenburger Str. 3, D-76187 Karlsruhe, Germany. E-mail: Lachenmeier@web.de" target="_blank" data-mce-href="mailto:Lachenmeier@web.de">Lachenmeier@web.de.
Absinthe was one of the most popular alcoholic beverages in late 19th century Europe. The emerald green drink was consumed by people from all walks of life, including the bohemian upper class, artists, poets and intellectuals. The most remarkable celebrity known as an absinthe drinker is the Dutch post-impressionist painter Vincent van Gogh (1853-1890). Other famous painters of the time, such as Henri de Toulouse-Lautrec and Paul Gaugin, and illustrious poets like Oscar Wilde, Charles Baudelaire, and Edgar Allan Poe were all fond of absinthe.
The wormwood plant (Artemisia absinthium L.) gave absinthe its name and is, together with alcohol, the main component of this spirit drink. Renewed interest in absinthe has been raised by the fact that, after a long prohibition in many European countries, wormwood was again allowed as an ingredient in alcoholic beverages in 1988. Currently over 100 types of absinthe are legally available (Lachenmeier et al. 2006).
During our research on absinthe, we discovered that there is a general misunderstanding amongst the public, as well as in the scientific community, about the properties of absinthe in general, and the thujone content in particular. It is remarkable that, even in peer-reviewed journals, unsubstantiated myths and legends are continually repeated.
Misinformation about thujone in absinthe
The first and foremost mistake regarding absinthe is the theory that there is a significant thujone content in the spirit. Thujone is a bicyclic monoterpene (Figure 1) that can be present in wormwood oil with very large variance in quantity (0-70%, dependent on chemotype and cultivation area).
Often values as high as 260 mg/l were misleadingly used to describe the so-called "historical thujone content" of pre-ban absinthe. In this context, it must be stressed that the structure of thujone was only correctly described in 1900 by Semmler. The first systematic gas chromatographic (GC) study of wormwood oils was conducted by Chialva et al. in 1983 who showed that the pre-GC view that thujone is the chief constituent of wormwood was over-simplified as there are a number of different wormwood chemotypes - a fact that is often ignored even in current literature.
The following point about the thujone content of pre-ban absinthe should be stressed: there are no analyses from the 19th century because neither knowledge about thujone nor the required analytical methodologies were in existence. Therefore, so-called "historical thujone contents" are either speculative or derived from calculations using historic recipe books, experimental production of absinthes using such recipes, or analyses of vintage absinthes.
The most conclusive evidence is provided by a number of studies about the experimental production of absinthes, and the analyses of vintage absinthes, which consistently showed that they contained only relatively low concentrations of thujone (< 10 mg/l) (see Padosch et al. (2006) for details). It was consequently concluded that the thujone content of absinthe had been overestimated in the past.
Absinthism - a fictitious syndrome?
With the increasing mass consumption of absinthe in the late 1800s, more and more of the chronic — and most probably high-level — absinthe consumers allegedly developed seizures, speech impairment, sleep disorder, mental prostration, auditory and visual hallucinations and finally death. This collection of symptoms gave birth to the term "absinthism;" it is unclear, however, if this condition ever really existed at all.
Both the serious and populist medical literature of the day demonized absinthe, in many cases paving the way for the anti-absinthe temperance movement. It should be stressed that clinical reports produced in the early days were more or less purely descriptive, or speculative, as causal connections between absinthe and wormwood and the above-mentioned symptoms could not be reliably proven. However, experimental studies were performed on animals which suggested that wormwood was the causative agent of absinthism (particularly the seizures). All these studies were carried out using so-called "essence d'absinthe" (pharmaceutical wormwood extracts) or pure etheric oil of wormwood; frequently, however, only the term "absinthe" was used to describe these extracts. It should be stressed that only the "essence d'absinthe" and not the ready-to-drink alcoholic beverage (in France called "extrait d'absinthe") triggered seizures in animals. However, these experiments with "essence d'absinthe" were generalized and findings were applied to humans who drank high concentrations of alcohol flavoured with low concentrations of wormwood extract. Sleeplessness, tremors, hallucinations, paralysis, and even seizures, are considered to be established symptoms of simple alcoholic excess. The only consistent conclusion that can apparently be drawn from all these animal experiments, is that wormwood oil, but not absinthe is a potent agent for causing seizures in animals.
The concept of absinthism was introduced into late 19th century medicine together with the first emerging descriptions of alcoholism. Due to the low solubility of etheric oils, absinthe usually contains high concentrations of ethanol, which means that there was no ingestion of wormwood without ingestion of high quantities of ethanol. In a recent literature review, Padosch et al. (2006) concluded that absinthism, as a clinical condition of its own, cannot be conclusively distinguished from chronic alcoholism.
Is it possible to manufacture a legal absinthe according to pre-ban recipes?
Besides the thujone myth, the most frequent misconception about absinthe appears to be the "common knowledge" that absinthe cannot be legally manufactured using pre-ban recipes. Simultaneously, with allowing wormwood to again be used as an ingredient of alcoholic beverages, maximum limits for thujone were established. A maximum limit of 35 mg/l in bitters, recommended by the Codex Alimentarius Commission of the FAO/WHO (1979) after toxicological evaluations, was adopted by many countries including the European Union and Switzerland. The maximum limit, in combination with the thujone myth and fear about absinthism, may have persuaded producers to disregard historic recipes and pre-ban production methods at the beginning of absinthe's renaissance in the 1990s. This may explain the high numbers of low-quality products found on the market that are artificially green-coloured and flavoured, without any content of wormwood or resemblance to pre-ban absinthe (Lachenmeier et al. 2006). Recently, a number of authentic distilled and naturally coloured absinthes have become available on the market. Some high-quality absinthes were tested and given awards at the International Wine and Spirit Competition 2006. The buyer is recommended to look for such certificates as the market is overstocked with low-quality products improperly labelled as absinthe. Authentic products are difficult to find.
Finally, it should be emphasised that thujone values in absinthes produced according to historical recipes confirm to today's maximum limits. The thujone content of absinthe has nothing to do with the spirit's quality. The most elegant way to totally avoid thujone is to use the thujone-free wormwood herb, which is available in certain cultivation areas and appears to be perfect for use in the spirits industry. The question posed above can, therefore, be answered by a definitive "yes".
Marketing with unproven secondary effects of absinthe
Some absinthe manufacturers and suppliers tend to advertise the supposed psychoactive or aphrodisiac properties of absinthe on their websites. Absinthe is also often and misleadingly advertised as having a cannabis-like effect. This is based on a hypothesis from the 19th century suggesting that absinthe acts in the same way as hashish. The hypothesis was renewed in 1975 by relatively far-fetched findings stating that, because of structural similarities between thujone and tetrahydrocannabinol (THC), both substances might activate the same receptor in the central nervous system (del Castillo et al. 1975); this could not be proven in later experiments (Meschler et al. 1999). The THC-absinthe connection may serve as an archetype modeling how conjectural scientific evidence can enter modern culture. A search on Google for "absinthe and THC" currently produces approximately 37,600 hits, mostly shopping sites, which advertise absinthe for psychoactive effects. In one case, the declaration "cannabis-like effect" was even found on a bottle label.
However, based on current available evidence, commercially manufactured absinthe appears not to cause detrimental health effects other than those encountered in alcoholism. All advertisements of aphrodisiac, psychotropic or other "secondary effects" of absinthe may, therefore, be misleading to the consumer. Consumers need to refocus their attention away from absinthe's thujone myth, former reputation and supposed effects, and start to choose absinthe purely for quality and taste like any other spirit.
Chialva, F., Liddle, P. A. P. and Doglia, G. 1983. Chemotaxonomy of wormwood (Artemisia absinthium L.) I. Composition of the essential oil of several chemotypes. Zeitschrift fÃ¼r Lebensmittel Untersuchung und Forschung 176(5): 363-366.
Codex Alimentarius Commission of the FAO/WHO. 1979. Report of the 13th session of the codex committee on food additives. Alinorm 79/12-A.
del Castillo, J., Anderson, M. and Rubottom, G. M. 1975. Marijuana, absinthe and the central nervous system. Nature 253(5490): 365-366.
Lachenmeier, D. W., Walch, S. G., Padosch, S. A. and Kröner, L. U. 2006. Absinthe - A review. Critical reviews in food science and nutrition 46(5): 365-377.
Meschler, J. P. and Howlett, A. C. 1999. Thujone exhibits low affinity for cannabinoid receptors but fails to evoke cannabimimetic responses. Pharmacology, biochemistry, and behaviour 62(3): 473-480.
Padosch, S. A., Lachenmeier, D. W. and KrÃ¶ner, L. U. 2006. Absinthism: a fictitious 19th century syndrome with present impact. Substance abuse treatment, prevention, and policy 1(1): 14. (http://www.substanceabusepolicy.com/content/1/1/14, open access)
Semmler, F. W. 1900. Ueber Tanaceton und seine Derivate. Berichte der deutschen chemischen Gesellschaft 33(2): 275-277.
Recommended internet links
http://en.wikipedia.org/wiki/Absinthe: Good introductory article about absinthe from Wikipedia, the free encyclopedia.
www.oxygenee.com/absinthe-museum.html: The Virtual Absinthe Museum provides a range of original artifacts documenting every aspect of the history of absinthe. Especially the collected 19th century guides to distillation techniques are highly recommended reading.
www.thujone.info: Collection of scientific research about thujone in absinthe.
www.iwsc.net: The International Wine and Spirit Competition has awarded some high-quality absinthes.
www.wormwoodsociety.org: The Wormwood Society is a private organization founded to help promote accurate, current information about absinthe.
About the author
Dirk W Lachenmeier is a Certified Food Chemist and Laboratory Head at the Chemical and Veterinary Investigation Laboratory (CVUA) of Karlsruhe. He holds a doctorate in Forensic Toxicology from the University of Bonn. His multi-faceted interdisciplinary research interests span from Food Science and Technology, Legal and Forensic Medicine and Toxicology to Biochemistry, Analytical Chemistry and Chemometrics. Dr. Lachenmeier has authored more than 50 peer-reviewed publications. As primary and co-author of a number of recent studies about absinthe performed in collaboration with academic and industrial partners, he researched and reviewed all aspects of the wormwood-flavoured spirit.
The CVUA Karlsruhe participates in official food and animal health control in the German Federal State of Baden-WÃ¼rttemberg. A wide range of products is examined (e.g. food, cosmetics, and pharmaceuticals), and the diagnosis of zoonoses as well as manufacturing hygiene controls are performed. The CVUA Karlsruhe is one of the most renowned institutes in Germany for the analysis and evaluation of alcoholic beverages.
More information regarding the CVUA Karlsruhe can be found on www.cvua-karlsruhe.de.