According to Organic Authority, an online resource for information on produce, garlic can have a number of health effects, whether eaten in food or taken as a nutritional supplement. It potentially keeps colds and infections from worsening, may improve blood sugar levels and assuredly prevents scurvy with its high vitamin C content. It also causes noxious bad breath.
It is no surprise that eating garlic can foul up the mouth. A relative of the onion and leek, it is well known for its pungent aroma, which not only stinks up teeth and tongue but stains fingers and can be extremely difficult to wash away.
Garlic’s odorous origin is allyl methyl sulfide, a compound that is found in garlic more than any other plant. Sulfur-based molecules are infamous for causing halitosis, with a similar compound - hydrogen sulfide - causing “natural “ bad breath whenever emitted by bacteria in a dry mouth.
Allyl methyl sulfide, however, is much more difficult to be rid of. Just as washing the hands may not remove the smell of garlic, brushing the teeth often does little to eliminate the odor, although it thankfully removes any garlic particles that could potentially continue to emit the reek of garlic.
Individuals with garlic breath may consider using specialty breath freshening products that employ chlorine dioxide, which neutralizes sulfuric compounds in the mouth and sweetens oral odor.