Too Much Licorice Stopped Man’s Heart and Killed Him, Doctors Say

Black licorice candy.
Black licorice candy.
Photo: Patrick Silson (AP)

A Massachusetts man’s fateful switch to licorice candy seems to have sent him to an early grave. In a case report published in the New England Journal of Medicine, doctors described how the man’s recent habit of eating a bag of black licorice every day likely led to his sudden cardiac arrest, kidney failure, and eventual death.


The report was presented as a teaching exercise for doctors and medical students—part of a longstanding tradition of the journal. Outside doctors are asked to diagnose a patient based on their initial symptoms and medical history upon admission, with the details of the case all taken from the genuine but anonymous patient records of the Massachusetts General Hospital. Afterward, the patient’s actual diagnosis and outcomes are revealed.

In this case, a 54-year-old construction worker was admitted to the hospital with sudden cardiac arrest, his heart having stopped beating in the middle of the day while he was at a fast food restaurant. Though the hospital was able to stabilize him, he had experienced multi-organ failure, particularly his kidneys, and he was admitted to the cardiac intensive care unit. Three hours later, his family arrived and was able to fill in some of the man’s medical history and relevant habits.

Though the man did have some preexisting conditions, including chronic hepatitis C, there was no apparent history of cardiovascular problems or other chronic ailments that could have explained his drastic turn for the worse. His family did tell doctors that he had a poor diet and that he loved candy. More importantly, they mentioned he had switched from eating fruity soft candy to eating a bag or two of licorice-flavored soft candy three weeks earlier, a decision that was likely his downfall, doctors concluded.

That’s because the somewhat-sweet flavor of licorice (the authentic black licorice kind, not what you find in red licorice candy) comes from a chemical called glycyrrhizic acid. Too much or chronic consumption of glycyrrhizic acid can cause our body’s level of potassium to plummet, which can then affect everything from our nervous system to our heart. As it happens, an abnormally slow beating heart is a well-known risk of low potassium levels caused by licorice consumption, which can then trigger cardiac arrest.

Unfortunately, the man’s prognosis following his sudden cardiac arrest was grim, and after consulting with doctors, the family opted for him to only receive palliative care. Just 32 hours after his symptoms began, the man died with his family by his bedside, according to the report.


Black licorice is rarely ever this dangerous, thankfully. It takes eating a lot of it for a while for licorice to really pose any health risks, and simply the act of not eating it anymore will usually boost potassium levels back to normal. Still, the Food and Drug Administration now explicitly warns people over the age of 40 to moderate their love of licorice, noting that eating 2 ounces a day for at least two weeks has been linked to an irregular heart rhythm and other health problems.

Given that Halloween is right around the corner, that remains good advice.


Science writer at Gizmodo and pug aficionado elsewhere


Arcanum Five

This is why black licorice tastes so disgusting. It’s nature’s way of saying “DON’T EAT THIS!” It’s like protective coloration on venomous animals and other toxic plants.

Peeps and circus peanuts, on the other hand, are quite good for you.