The Mouthwash Debate

Bacteria that cause bad breath release sulfur compounds are "anaerobic," which means they thrive without oxygen. They love to burrow into the surface of the tongue, and they thrive in inflamed gums. Smoking causes bad breath. "It makes the mouth extremely dry, instantly," says Katz. (His 50-page "Bad Breath Bible" is free on his Web site.) So does eating onions and garlic. "If it smells going in, it will smell going out," says Price. "We eat something that goes into our bodies and ends up in our bloodstream. You're breathing it out." People who are lactose intolerant may have problems with their breath after drinking milk, says Katz. "It's an overload of proteins in their mouth." Sugary foods, including Altoids, feed bacteria and encourage its growth, so they also promote bad breath.

Who should avoid alcohol-containing mouthwash? Alcoholics, and kids. Children's livers aren't fully developed, so alcohol exposure can be toxic and even put them in a coma, says P&G's Doyle. "It's dangerous to leave this stuff lying about," says Northwestern's Hurst. "Leaving it lying about is like leaving a bottle of spirits about. It has the potential of an intoxicant." Other doctors agree. "You want to warn children against using alcohol-containing mouthwash," says Karabin. "Children don't tend to use things as directed." (Listerine officials note that they do not recommend that anyone swallow Listerine. "It's created so it's unpalatable for drinking," says Johnson & Johnson's Chris Charles.)

What mouthwashes, if any, do the experts use? The ADA's Price doesn't use them. Instead, he is a big believer in brushing and scraping the tongue. Hurst doesn't regularly use them. Shah gargles with a homemade mouthwash made from mixing a cup of warm water with a half teaspoon of baking soda. Karabin uses an alcohol-containing mouthwash because she thinks it kills the bacteria better than alcohol-free ones. She does not like homemade mouthwashes made from baking soda, because she says they get rid of some bacteria but not others and tend to lead to an "overgrowth of fungus." Rinsing with hydrogen peroxide also promotes fungal growth, she says.

The bottom line? "The best thing you can do for oral health is buy a three-minute egg timer," says Price, who wants people to spend that long brushing and flossing. "How much time do you spend blow-drying your hair?" And of course, wet hair doesn't smell—but dirty teeth do.

© 2008