Diagnostic dilemma: A man's heart stopped after he ate too much licorice

The patient: A 54-year-old man in Boston

The symptoms: The man was at a restaurant when he suddenly gasped, started shaking uncontrollably and lost consciousness.

What happened next: An emergency medical team performed CPR and determined that the lower chambers of the man's heart were malfunctioning so they could not pump blood properly. The team gave the man drugs to normalize his heart rhythm and keep the heart pumping. The man briefly regained consciousness but passed out again before reaching the hospital.

The diagnosis: Hospital doctors confirmed that the man had experienced cardiac arrest, in which the heart suddenly stops beating.

The treatment: He received IV fluids to stabilize his vitals, as well as drugs to help restart his heart and relieve pain. A tube was inserted into his airway to support his breathing while a mechanical pump was placed to help his heart work. Lab tests revealed that he had too little potassium in his blood, so he was given the essential mineral via IV. Despite these and other treatments, though, the man's condition worsened to multiorgan failure. He died 32 hours after being admitted to the hospital.

What makes the case unique: The cause of this patient's fatal condition might seem harmless: licorice-flavored candy. The man's family informed his doctors that he had been eating one to two large packages of soft candy each day. Three weeks prior to the cardiac arrest, the patient had switched from fruit-flavored to licorice-flavored candy.

Candies flavored with real licorice contain a compound called glycyrrhizin. This compound blocks an enzyme in the kidneys, causing them to retain too much water and sodium and to expel too much potassium. Potassium is needed for the heart to pump properly, so losing too much of the mineral can lead to serious — and sometimes deadly — heart problems.

The Food and Drug Administration warns that "if you're 40 or older, eating 2 ounces (56 grams) of black licorice a day for at least two weeks could land you in the hospital with an irregular heart rhythm." Licorice can also interfere with certain medications, so if you eat this candy, it's best to do so in moderation.

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