A tasty Indian meal is often worth the after-dinner halitosis that can come with it. It is widely accepted that curry and other Indian spices can cause bad breath, though some researchers used to believe the opposite.
In a 1994 issue of the British Medical Journal, researchers from the MGM Medical College in Mumbai, India, wrote an editorial suggesting that curry spices actually decrease oral odor. They noted that many of the same essential oils found in U.S. mouthwashes also exist in curry leaves.
After noting that 2.6 percent of curry leaves consist, by weight, of oils that have antifungal and antimicrobial properties, they suggested that chewing the leaves seemed to reduce bad breath in male volunteers.
More recently, however, a 2004 study in the Journal of Clinical Periodontology found that essential oils do little to reduce the amount of oral sulfuric compounds that give bad breath its scent.
In place of chewing a spicy leaf after a meal, a more effective method of oral care may be to brush and then rinse with a specialty breath freshening mouthwash.