Although spices have been important for centuries in food preparation throughout the world, patterns of spice use differ considerably among cultures and countries. What factors underlie these differences? Why are spices used at all? To investigate these questions, we quantified the frequency of use of 43 spices in the meat-based cuisines of the 36 countries for which we could locate traditional cookbooks. A total of 4578 recipes from 93 cookbooks was analysed. We also complied information on the temperature and precipitation in each country, the ranges of spice plants, and the antibacterial properties of each spice. These data were used to investigate the hypothesis that spices inhibit or kill food-spoilage microorganisms. In support of this is the fact that spice plant secondary compounds are powerful antimicrobial (i.e., antibacterial and antifungal) agents. As mean annual temperatures (an indicator of relative spoilage rates of unrefrigerated foods) increased, the proportion of recipes containing spices, number of spices per recipe, total number of spices used, and use of the most potent antibacterial spices all increased, both within and among countries. Likewise, the estimated fraction of bacterial species inhibited per recipe in each country was positively correlated with annual temperature. Several alternative hypotheses were considered--that spices provide macronutrients, disguise the taste and smell of spoiled foods, or increase perspiration and thus evaporative cooling; it also is conceivable that spice use provides no benefits. However, none of these four alternatives was well supported by our data. The proximate reason spices are used obviously is to enhance food palatability. But the ultimate reason is most likely that spices help cleanse foods of pathogens and thereby contribute to the health, longevity and reproductive success of people who find their flavors enjoyable.

pices are plant products used in flavoring foods and beverages. For thousands of years, aromatic plant materials have been used in food preparation and preservation, as well as for embalming, in areas where the plants are native, such as Hindustan and the Spice Islands (Govindarajan 1985, Dillon and Board 1994). During and after the Middle Ages, seafarers such as Marco Polo, Ferdinand Magellan, and Christopher Columbus undertook hazardous voyages to establish routes to trading ports in primary spice-growing regions (Parry 1953). The spice trade was so crucial to national economies that rulers repeatedly mounted costly expeditions to raid spice-growing countries, and struggles for the control of these countries precipitated several wars. When Alarich, a leader of the Goths, laid siege to Rome in AD 408, he demanded as ransom various precious metals and 3000 pounds of pepper (Scheiper 1993).Today, spice use is ubiquitous, but spices are far more important in some cuisines than others. Most people have experienced this variability firsthand, when traveling in foreign lands, dining at international Humans have borrowed plants' chemical "recipes" for evolutionary survival for use in cuisine to combat foodborne microorganisms and to reduce food poisoning restaurants, or preparing exotic recipes at home. Japanese dishes are often "delicate," Indonesian and Szechwan dishes "hot," and middle European and Scandinavian dishes "bland." Usually these differences are merely chalked up to cultural idiosyncrasies. Several years ago, we became curious about this interpretation. We wondered if there are any predictable patterns of spice use and, if so, what factors might underlie them. In this article, we summarize the results of our inquiries. We found that spice use is decidedly nonrandom and that spices have several beneficial effects, the most important of which may be reducing foodborne illnesses and food poisoning. What is a spice?"Spice" is a culinary term, not a botanical category-it does not refer to a specific kind of plant or plant part (Farrell 1990). Indeed, spices come from various woody shrubs and vines, trees, aromatic lichens, and the roots, flowers, seeds, and Patterns of spice useConventional wisdom tells us that cuisines of tropical countries are spicier than those of northern countries, but patterns of spice use around the world have not been quantified.To do so, we located "traditional" cookbooks, which were written primarily to archive the author's native cuisine. We analyzed recipes in 93 traditional cookbooks from 36 counties (at least two books from each country) and quantified the use of 43 Paul W. Sherman is a professor at Cornell University. He studies the behavioral ecology of various birds and mammals and teaches animal behavior and Darwinian medicine. Jennifer Billing was an undergraduate Honors student at Cornell when she began studying spices. She now teaches biology and chemistry at The Dalton School in New York City. 0