When you bite down on a clove of raw garlic, a pleasurable hell breaks loose. First there’s the pungent scent that sears your nostrils, then your tongue catches fire, and if it’s a really hot clove, tears spring to your eyes. This is just the allium sativum's way of fending off squirrels, rats and other pests—that is, all of us who are addicted to the taste and smell of the “stinking rose.”
According to a study at the University of California at San Francisco and Lund University in Sweden, the simple act of crushing a clove starts a complex chemical reaction that fires up our pain neurons. In the August 23, 2005 Proceedings of the National Academy of Sciences (“Pungent Products from garlic activate the sensory ion channel TRPA1”), scientists found that eating garlic releases thiosulfinate allicin, a sulfurous compound that opens a specific cellular ion channel. Once the gates have been breached, other ions pile on, sending pain messages to the spinal cord and the brain as they inflame mucus membranes in the mouth and nose. Other fiery foods—wasabi, mustard and chilies—use similar channels to excite pain receptors.
Why do we like the sting of garlic and other spicy foods? In On Food and Cooking (2nd edition), Harold McGee suggests that the experience may be akin to the exhilaration of riding a rollercoaster or plunging into Lake Michigan in January. Eating salsa made with raw garlic may send danger signals to the brain, but since we know it won’t really hurt us, we “can savor the vertigo, shock and pain for their own sakes.” Endorphins kick in, creating a pleasurable glow as the pain fades.
And according to a 2005 Scripps Research Institute study published in Current Biology ("The Pungency of Garlic: Activation of TRPA1 and TRPV1 in Response to Allicin"),food may even taste better when the mouth is irritated by garlic’s sulfurous compounds. One of the study’s authors, associate professor Ardem Patapoutian, told National Geographic News that “…the activation of…pain neurons causes hypersensitivity in the mouth, so that other sensory/taste stimuli are enjoyed at more intense levels.” That means, when you eat salsa with, say, a beef fajita, the garlic inflames the mouth, heightening the flavor of the grilled meat, ripe tomatoes and, indeed, all the other ingredients.
Here’s a classic salsa recipe for Pico de Gallo (literally “rooster’s beak”). Serve it with homemade tortilla chips, or on top of scrambled eggs, or with any grilled meat, chicken or fish--or just eat it by the spoonful.
Pico de Gallo (Tomato, Cilantro and Garlic Salsa)
Makes about 3 cups
1 pound plum or other ripe tomatoes, chopped
4-5 cloves of garlic, finely chopped, or to taste
1 medium yellow onion, finely chopped
1 small bunch cilantro, leaves finely chopped
1 or more Serrano chilies, seeds removed and finely chopped
1 tablespoon canola oil
Salt to taste
Lime juice to taste
Combine the tomatoes, garlic, onion, cilantro, Serrano chilies and canola oil in a large bowl. Add salt and lime juice to taste. Allow the flavors to mingle for at least 30 minutes before serving. Taste the salsa once more before bringing it to the table, adding more of any ingredients if desired.
Editor’s Note: To read the original articles cited in this post, go to the websites for The Proceedings of the National Academy of Sciences and Current Biology. See also Harold McGee, On Food and Cooking: The Science and Lore of the Kitchen, Scribner, 2004.