Paper or plastic? At first, it was polite of grocery store cashiers to ask which sort of bag we’d prefer. But today, the question often sounds like, “Environmentalist or Polluter?” Everyone knows that paper is the best choice for protecting the planet. Or is it? A recent Wall Street Journal article noted, “There is growing evidence that the production, use and disposal of plastic bags put less burden on natural resources than paper bags.” So, reusable bags must be the answer, right? Not so fast. A recent study found reusable bags to be breeding grounds for bacteria.

Short of shunning the grocery store altogether in favor of growing all of our own food, it seems that the best option for carrying our groceries home is a reusable bag. Just make sure to wash it every now and then (This Newsday.com article explains the non-intuitive nuances of how to do so properly).