A Massachusetts construction worker’s love of black licorice wound up costing him his life. Eating a bag and a half every day for a few weeks threw his nutrients out of whack and caused the 54-year-old man’s heart to stop, doctors reported Wednesday.

“Even a small amount of licorice you eat can increase your blood pressure a little bit,” said Dr. Neel Butala, a cardiologist at Massachusetts General Hospital who described the case in the New England Journal of Medicine.

The problem is glycyrrhizic acid, found in black licorice and in many other foods and dietary supplements containing licorice root extract. It can cause dangerously low potassium and imbalances in other minerals called electrolytes.