For thousands of years humans have been seeking a remedy for bad breath. The ancient Greeks tried chewing gum mastic, or tree resin. So did early American settlers, who were partial to the rubbery sap of the white spruce.

In most cases, preventing bad breath is as simple as brushing your teeth twice a day and flossing daily. And don't forget to brush your tongue, scrubbing as far back as you can: Germs in the pits and crevices of the tongue's surface, marked by a white coating in the morning, are key causes of bad breath. The Cherokee used a foamflower mouthwash to fight what they called "the white-coated tongue."

But brushing thoroughly isn't the whole solution. A good flow of saliva is necessary for sweet-smelling breath, since the oxygen in saliva kills bacteria. Saliva flow is decreased when you sleep--the reason people wake up with "morning mouth." Some medications also dry the mouth, and the mouth also becomes drier with age. You can stimulate saliva flow by chewing sugarless gum or eating raw vegetables. You should try to drink at least eight glasses of water or other fluids a day, but avoid coffee, tea, and alcohol, which dry the mouth.

If bad breath persists, consult your dentist; the problem may be the result of gum disease. If it isn't, your doctor should investigate a possible medical cause.

Herbal Remedies

Sage Bad breath caused by oral infections may be fought by the anti-inflammatory and antiseptic action of thujone, one of the active principles in common sage. To make a tea, pour 1 cup boiling water over 1 tablespoon of chopped fresh sage leaves (1 to 2 teaspoons dried), let steep, then strain. Drink the tea slowly for maximum effect.

Myrrh An antiseptic, myrrh kills oral bacteria. Make a mouthwash by stirring 5 to 10 drops of myrrh tincture into a glass of water. Mixing the tincture with mint or rosemary tea will enhance its breath-freshening effect and mask myrrh's disagreeable taste. But be careful to watch for skin irritation.

Fennel seed Lovers of Asian food may be familiar with fennel seeds, which are often offered as an after-dinner treat at Indian restaurants. Chewing a small handful will help freshen the breath. Look for the seeds in the spice section of a grocery store.

Peppermint The menthol in peppermint can mask bad breath temporarily. Steep 2 tablespoons chopped leaves and flowering tops (or 1 teaspoon dried peppermint) in 1 cup boiling water for 10 minutes. Strain, then drink.