Eugenol
Polyphenols
The scent of clove, and the antiseptic dentists have always used.
Gram for gram, clove is the densest food in polyphenols in the whole catalog, and eugenol accounts for almost all of it.
Effects and benefits
Bite a clove: your tongue goes numb. Eugenol blocks the channels of pain nerves, the same action that made it an ally of dental offices. In the laboratory, it also slows many bacteria, including those of plaque.
Eugenol makes up 70 to 90% of clove essential oil. It acts on the sodium channels of nerves, like a local anesthetic, and on a heat receptor, TRPV1 (Park et al., 2006). Mixed with zinc oxide, it is still used as a temporary dental dressing.
In the laboratory, it pierces the membrane of many bacteria and fungi (Marchese et al., 2017); the effect in the gut has not been measured in humans.
Pure, it is irritating: the essential oil is not to be swallowed. In a dish, a few cloves provide only small amounts.
Sources: Park et al., 2006 · Marchese et al., Crit Rev Microbiol, 2017