Did you know you can taste garlic through your feet? Crush some fresh garlic, rub it on the bottom of your feet, wait for a while, and supposedly you will start tasting garlic in your mouth. It sounds laughable at first, mainly because we obviously do not have taste buds in our feet. But there is some real chemistry behind the experiment. The American Chemical Society (ACS) has featured the experiment, and the Tisserand Institute, an educational platform studying essential oils, has discussed it in detail.
The study suggested that if someone notices a garlic-like taste or smell afterward, the explanation has more to do with garlic compounds, the skin, the bloodstream and our sense of smell than with some hidden taste mechanism in the feet.
According to the ACS, “Chemistry can do some wild tricks with food.” The experimenting body noted that it is not because we have secret garlic taste buds on our feet. It is because the molecules responsible for garlic’s smell (allicin) can penetrate in our skin, get into your blood and travel to our mouth and nose, where we suddenly start to sense the taste of garlic.
As per the study, inside an intact garlic clove, a compound called alliin is kept separate from an enzyme called alliinase. Crushing the garlic breaks the cells and brings them together. Alliinase then converts alliin into allicin, a reactive sulfur-containing compound associated with the characteristic smell of freshly crushed garlic.
Allicin does not simply sit in the body unchanged either. It can break down into several other sulfur compounds. Researchers studying people who consumed garlic have detected compounds including allyl methyl sulfide, diallyl sulfide and diallyl disulfide in their breath. Allyl methyl sulfide is particularly interesting because it can stick around in the body and is one of the compounds responsible for the familiar “garlic breath” that can survive long after the meal is over.
So where do the feet come into this? The skin is not an impenetrable wall, experts noted. Some chemicals can cross it, although how much gets through depends on the particular chemical, its concentration, the condition of the skin and the area where it is applied.
The soles of the feet are actually covered by a relatively thick outer layer of skin, so they are not necessarily an efficient entry point. The Tisserand Institute used the garlic experiment as an example of the fact that some garlic-derived compounds can cross the skin, but it also made an important qualification: the experiment does not tell us that large or medically significant amounts of those compounds are entering the bloodstream.
There is another piece of the puzzle: taste and smell are closely connected. When we say that something “tastes” like garlic, part of what we are experiencing is actually our sense of smell. Garlic-derived volatile compounds can eventually be detected in exhaled breath, and our olfactory system is extremely sensitive to many sulfur-containing molecules. But most of the strong scientific evidence for garlic compounds appearing in breath comes from eating garlic or taking garlic preparations, not from rubbing garlic on someone’s feet.
So it can be a mistake to take those studies and conclude that we know exactly how much garlic compound reaches the bloodstream after applying garlic to the soles of the feet. The foot experiment is interesting, but it is not a proof of a major drug-delivery route through the feet.
It is also important to note that experts do not recommend trying this experiment for hours at home: raw garlic can irritate and even burn skin. There are published medical case reports of people developing blistering and chemical burns after leaving crushed or freshly cut garlic against their skin, sometimes under a covering.
Retrospectively, our feet cannot taste garlic, but compounds from garlic can interact with the skin, and garlic’s volatile sulfur chemistry can eventually produce sensations that we perceive through your mouth and nose.
