When I was growing up, we had a VHS tape of Arsenic and Old Lace that I watched probably a hundred times. It was one of my mother’s favorite movies. The story is very silly, but if you’ve never seen it, the plot circles around a couple of eccentric old ladies who take old bachelors out of their misery by serving them wine spiked with arsenic.
Indeed, arsenic has a fine tradition as a silent killer, and the detection of it in the body of a dead person spawned the development of forensic science as we know it today. Since it’s a known poison, it must be pretty dangerous, right?
Well, not necessarily.
Arsenic is very common. Low levels of it are found in soil, water, and air, and are then absorbed by plants, including vegetables and grains we eat every day. Prolonged exposure to low levels of arsenic can affect the way your cells communicate, which means it could play a role in the development of diseases like diabetes and cancer.
In the 1800s, taking arsenic as a health supplement was all the rage for a while. Visitors to Styria in southeast Austria reported that the residents there put a little in their coffee. Men and women took it to clarify their complexions and help with breathing problems. Scientists who visited the region observed that the arsenic didn’t seem harmful, and that in fact, many of the arsenic-eaters seemed quite strong and healthy. When pale complexions were the fad, women applied arsenic to their faces, which constricted capillaries and made skin look whiter. Peddlers of arsenic health tonics pushed taking it orally to treat a plethora of maladies.
Since arsenic was so common, deaths by arsenic poison became more common as well, be it deliberate poisoning or accidental. By the 1920s, the arsenic’s connection to death by poison was too well publicized, and taking it went out of fashion. (For more on the history of arsenic tonics check out this article at io9.)
Today we recognize that prolonged exposure to arsenic can indeed be dangerous, though there is some evidence that people can build up a tolerance to it. Though it is a carcinogen, exposure to arsenic has been found to decrease instances of certain kinds of cancer. Evidence indicates that the people in one region in South America have been exposed to arsenic for so long that they’ve developed a gene that helps them better flush toxins from their systems, which may help reduce the ill effects of exposure to carcinogens. A form of arsenic called arsenic trioxide has also been used to treat leukemia.
Arsenic trioxide is sold over the counter at some drug and supplement stores as arsenicum album. This is arsenic in its homeopathic form, and it is used to treat a variety of maladies, particularly indigestion.
But don’t go running out to buy arsenic supplements just yet—it’s still a poison and can be dangerous if too much is ingested. It’s a good idea to talk to an expert first. Arsenic should be avoided by women who are pregnant or breast-feeding, too. If taking arsenicum album, consult a doctor right away if indigestion or stomach ache persist.