Eating too much licorice can lead to irregular heartbeat or even heart failure due to its glycyrrhetinic acid content. If you tend to overchew, you might be advised to seek out DGL (de-glycyrrhizinated) licorice. Stawberry Twizzler fiends need not worry. About this anyway. From Smithsonian (Wikipedia image):
When consumed in large quantities, (glycyrrhetinic acid) can cause your body’s potassium levels to fall to the point that some people experience arrhythmia, a rise in blood pressure, swelling and even congestive heart failure. People taking diuretics or medications for high blood pressure should be especially wary as the licorice may inhibit the effectiveness of the drugs. How much is too much? According to the FDA, a diet including 2 ounces of black licorice a day for two weeks might merit a trip to the hospital to have an irregular heart beat checked out. And consuming one to two pounds of licorice candy in one go may cause the blood vessels in your eyes to spasm, causing temporarily impaired vision. Though predominately a concern for persons over 40, it is recommended that everyone should moderate a high licorice intake.
David Pescovitz is Boing Boing's co-editor/managing partner. He's also a research director at Institute for the Future. On Instagram, he's @pesco.