The Scary Reason(s) You Might Want To Be Cautious With This Halloween Candy

from “Eat This, Not That”

The sweet stuff in your kids' trick-or-treat buckets may come with a bitter side effect. When eaten in large quantities (which in this case is anything over a mere 2 ounces, keep reading!), black licorice can cause serious health issues. This Halloween, you'll want to stay vigilant about the candy, whether you're looking out for your kids or just indulging your own sweet tooth.

"Consumed occasionally and in moderation, it's unlikely you would experience any detrimental effects from black licorice," explains GP clinical lead Dr. Daniel Atkinson at treated.com, a U.K.-based healthcare service. "But if you were to eat too much black licorice over a sustained period of time—more than 50 grams a day for two weeks straight, for example—then you are risking your health for a number of reasons."

Why is black licorice so dangerous? It all has to do with glycyrrhizin, licorice root's sweet compound. "Glycyrrhizin decreases potassium levels and increases sodium levels in the blood," Dr. Atkinson explains. And while you'd have to eat a good amount of licorice to get to that point, it could have some scary side effects.

A drop in potassium levels could lead to an abnormal heart rhythm in addition to heart failure, high blood pressure, edema, and lethargy, according to the FDA. "Potassium plays an important role in the body. It helps us better transmit nerve signals, aids normal muscle function, plays a role in the balance of fluids, and has a number of other functions, too," says Dr. Atkinson. "The term for low potassium levels is hypokalemia. This can lead to heart palpitations, irregular heartbeat, weakened muscle function, or even high blood pressure."

How much black licorice is too much? While 50 grams, or two ounces, might sound like a lot of candy, it's not actually that difficult an amount to reach, especially if you're a licorice lover. "This isn't actually as much as it sounds," Dr. Atkinson says. "A serving of 8-10 small pieces is probably between 40 and 50 grams."

Are certain people more at risk for the health risks black licorice poses? Adults over 40 and parents of young children will want to be especially careful of how much licorice they and their children are eating.

"Children have a smaller body surface area, which predisposes them to a higher risk than adults," explains Dr. Raj Singh, a Nevada-based nephrologist. The FDA also warns that several medical studies have linked licorice consumption with health problems in adults over 40.

In fact, a review in the journal Therapeutic Advances in Endocrinology and Metabolism found that overconsumption of this polarizing candy is linked to high blood pressure and hypokalemic myopathy, or low-potassium-level–related metabolic muscle weakness.

"Individuals with high blood pressure, especially those taking diuretics or water pills such as HCTZ (hydrochlorothiazide), are at the most risk, as these medications force the kidneys to waste potassium in the urine, which can cause severe hypokalemia (low levels of potassium in the blood)," Dr. Singh explains. "Individuals with atrial fibrillation (a common cardiac arrhythmia) are at high risk as even minor fluctuation in blood potassium levels can trigger a fatal arrhythmia." If you have those particular conditions, you might want to check with your doctor about how much black licorice is safe in your case.

How can you prevent black licorice's adverse effects? Make sure to stay below the FDA's recommended limit of two ounces a day. Also, it never hurts to beef up your diet with some potassium-rich foods to make sure your body's potassium stores aren't depleted.

"Theoretically, consuming a diet high in potassium (vegetables, bananas) or drinking potassium-rich fluids such as coconut water or orange juice can protect against the potassium-lowering effects of black licorice and stabilize the cardiac membrane," says Dr. Singh.

If you do end up experiencing any licorice-induced symptoms, contact your doctor right away. Halloween candy is can be fun treat, but this is one variety you'll want to be wary of.