The European horse meat scandal continues to widen. The equine ingredient was most recently found in the Swedish meatballs sold by furniture giant IKEA in at least two dozen European countries.

While horse meat has yet to be found in the U.S., Americans have reacted to the possibility with revulsion. But people in other countries regularly eat horse meat. So why is it such a taboo here? 

Marion Nestle is a professor of nutrition at New York University who blogs about food in politics and culture.