Black Licorice. Siohban Delancey is with the Food and Drug Administration. She says kids don't usually have a taste for it, but adults seem to develop one as they get older…and too much is a bad thing.
DELANCEY: "I remember as a child, my mother sneaking the licorice away from me which was actually fine with me, but we're finding that for people over 40, if they eat more than two ounces a day for more than two weeks, their potassium levels can fall and that can cause an irregular heart rhythm or arrhythmia."
Two ounces is about four large mouthfuls.
Also on the FDA's warning list: any contact lenses that come with a costume. Delancey says Avatar and Lady Gaga costumes come with contacts and are popular this year. But the contacts are not a one-size fits-all item and can cause permanent eye damage.