Why vegetable recipes are not very spicy

Spices are aromatic plant materials that are used in cooking. Recently it w as hypothesized that spice use yields a health benefit: cleansing food of p arasites and pathogens before it is eaten, thereby reducing food poisoning and foodborne illnesses. In support, most spices have antimicrobial propert ies and use of spices in meat-based recipes is greatest in hot climates, wh ere the diversity and growth rates of microorganisms are highest. A critica l prediction of the antimicrobial hypothesis is that spices should be used less in preparing vegetables than meat dishes. This is because cells of dea d plants are better protected physically and chemically against bacteria an d fungi than cells of dead animals (whose immune system ceased functioning at death), so fewer spices would be necessary to make vegetables safe for c onsumption. We tested this corollary by compiling information on 2129 veget able-only recipes from 107 traditional cookbooks of 36 countries. Analyses revealed that spice use increased with increasing ambient temperature, but less dramatically than in meat-based recipes. In all 36 countries, vegetabl e dishes called for fewer spices per recipe than meat dishes; 27 of these d ifferences were significant. Of 41 individual spices, 38 were used less fre quently in vegetable recipes; 30 of these differences were significant. Pro portions of recipes that called for > 1 spice and > 1 extremely potent anti microbial spice also were significantly lower for vegetable dishes. By ever y measure, vegetable-based recipes were significantly less spicy than meat- based recipes. Within-country analyses control for possible differences in spice plant availability and degrees of cultural independence. Results thus strongly support the antimicrobial hypothesis. (C) 2001 Elsevier Science I nc. All rights reserved.