For those who don’t know, absinthe is a grain alcohol of Swiss origin which is made by macerating herbs and spices, the most important of which are fennel, anise and wormwood. The first two give absinthe its characteristic licorice flavor. Wormwood imparts a bitter flavor and is the source of absinthe’s famed mystique and jade-green hue.

Absinthe is regulated by the Food and Drug Administration and, until recently, was completely banned in the US and most of Europe. The reason for this: absinthe contains thujone, a toxic chemical found in several edible plants including tarragon, sage and wormwood. Why is thujone so dangerous that its presence in your glass of booze needs to be regulated by the FDA? The answer has more to do with history than science.

Prior to the ban in the early 1900s, absinthe was ubiquitous. If you check out a list of famous people who drank absinthe, you’ll notice that there’s a lot of them.  That’s because basically everyone who was cool between 1850 and 1900 drank it. Being both the latest fad in booze and extremely high in alcohol, absinthe was sometimes to blame for bouts of raging drunkenness, occasional delirium and even death. Kind of like Four Loco today.

As its popularity spread, incidents of absinthe-related alcohol abuse spread as well. Society gradually came to associate absinthe with alcoholism and degeneracy in general. A French psychiatrist named Dr. Valentin Magnan even went so far as to blame absinthe for what he saw as a collapse of French culture.

Dr. Magnan set out to prove through scientific experiment that absinthe was the root of French society’s ills. He conducted all sorts of scientific experiments on animals using thujone and wormwood oil.  He observed that mice that ingested high concentrations of thujone had convulsions and died.  He even gave a dog a vial of wormwood oil and watched it go crazy and bark at a brick wall for half an hour. (This experiment, by the way, is the root of the myth that absinthe causes hallucinations. It doesn’t.)

These and other experiments seemed to confirm the common sense of the day: absinthe caused people to go crazy. It became common knowledge that wormwood had madness-inducing and psychoactive powers.

Then, in 1905, a Swiss man named Jean Lanfray murdered his wife and two daughters in a drunken rage one night. Lanfray had been drinking absinthe (as well cognac, brandy, crème de menthe, wine and beer) since breakfast, and the day before, and the day before, and the day before. The Lanfray trial put absinthe in the spotlight.

Combined with the evidence produced by Dr. Magnan, the crime was added to the narrative of the Temperance Movement which advocated a ban on absinthe.  By the early 1900s, the spirit was banned in most of Europe and the United States. The bans persisted for over a hundred years.

We now know that that the toxic effects of thujone were greatly exaggerated. An average sized adult male would have to consume about 30mg of thujone in order to feel its toxic effects which include tunnel vision, tremors and delayed reaction time. These effects are similar to other toxic chemicals, e.g. alcohol.

Wormwood

While Dr. Magnan’s experiments relied on high doses of pure wormwood oil and thujone, there isn’t actually that much thujone in absinthe. Gas chromatography tests on vintage absinthe bottles produced in the 19^th century revealed average thujone levels of 25mg/L. Some had levels as low as .5mg/L. Today, thujone levels in absinthe are capped at 10mg/L in the United States, and 38mg/L in Europe. That means you would die of alcohol poisoning before you consumed enough absinthe to be poisoned by 30mg of thujone. This was true even in Dr. Magnan’s time.

It kind of makes one wonder about the way we regulate scary chemicals. Thujone, like any other natural or artificial chemical, is only toxic at certain levels. The National Toxicology Program produces the “Report on Carcinogens” which is currently in its 12^th edition. The science behind this report frequently relies on experiments in which high doses of chemicals are administered repeatedly to rodents.  When these experiments, like Dr. Magnan’s, are understood in the context of preexisting societal fears, we shouldn’t be surprised by regulations that are out of all proportion to the threat posed by the chemicals.