ITHACA, N.Y. -- Fans of hot, spicy cuisine can thank nasty bacteria and other foodborne pathogens for the recipes that come -- not so coincidentally -- from countries with hot climates. Humans' use of antimicrobial spices developed in parallel with food-spoilage microorganisms, Cornell University biologists have demonstrated in a international survey of spice use in cooking.
The same chemical compounds that protect the spiciest spice plants from their natural enemies are at work today in foods from parts of the world where -- before refrigeration -- food-spoilage microbes were an even more serious threat to human health and survival than they are today, Jennifer Billing and Paul W. Sherman report in the March 1998 issue of the journal "Quarterly Review of Biology".
"The proximate reason for spice use obviously is to enhance food palatability," says Sherman, an evolutionary biologist and professor of neurobiology and behavior at Cornell. "But why do spices taste good? Traits that are beneficial are transmitted both culturally and genetically, and that includes taste receptors in our mouths and our taste for certain flavors. People who enjoyed food with antibacterial spices probably were healthier, especially in hot climates. They lived longer and left more offspring. And they taught their offspring and others: 'This is how to cook a mastodon.' We believe the ultimate reason for using spices is to kill food-borne bacteria and fungi."
Sherman credits Billing, a Cornell undergraduate student of biology at the time of the research, with compiling many of the data required to make the microbe-spice connection: More than 4,570 recipes from 93 cookbooks representing traditional, meat-based cuisines of 36 countries; the temperature and precipitation levels of each country; the horticultural ranges of 43 spice plants; and the antibacterial properties of each spice.