bad breath caused by garlic seems like a fairly simple process. You eat garlic; you get halitosis that smells like, what else, garlic. However, there is a lot more than that going on in a mouth afflicted by garlic breath, and researchers at the University of Minnesota recently set out to explain what causes this particular form of oral odor.
Their report, which appears in the American Journal of Physiology: Gastrointestinal and Liver Physiology, blames the smell of garlic breath in large part on allyl methyl sulfide, a volatile sulfur compound (VSC) that is mainly responsible for the odor of garlic.
The team tested for this and other VSCs - including methanethiol, allyl mercaptan, allyl methyl disulfide and allyl disulfide - on the breath of participants who ate six grams of raw garlic.
They reported trying to determine whether the smell of garlic breath emanates from the mouth or the stomach. Over the course of three hours, they determined through halimeter readings that the vast majority of garlic breath originates in the oral cavity.
Simply put, garlic breath occurs because allyl methyl sulfide and its sister molecules mix with saliva and then break free into exhaled air for hours afterwards.
Over time, this smell will slowly be replaced by that of other VSCs, which are emitted by oral microbes as they digest food particles in the mouth.
To nip garlic breath in the bud, individuals with halitosis may consider rinsing the mouth out with a moistening speciality breath freshener after any garlic-laden meal.