No evidence that spice consumption is a cancer prevention mechanism in human populations

Abstract

Background: Why humans historically began to incorporate spices into their diets is still a matter of unresolved debate. For example, a recent study (Bromham et al. There is little evidence that spicy food in hot countries is an adaptation to reducing infection risk. Nat Hum Behav 2021;5:878-91.) did not support the most popular hypothesis that spice consumption was a practice favoured by selection in certain environments to reduce food poisoning, parasitic infections, and foodborne diseases. Methods: Because several spices are known to have anticancer effects, we explored the hypothesis that natural selection and/or cultural evolution may have favoured spice consumption as an adaptive prophylactic response to reduce the burden of cancer pathology. We used linear models to investigate the potential relationship between age-standardized gastrointestinal cancer rates and spice consumption in 36 countries. Results: Patterns of spice are not consistent with a cancer mitigation mechanism: the age-standardized rate of almost all gastrointestinal cancers was not related to spice consumption. Conclusions: Direction other than foodborne pathogens and cancers should be explored to understand the health reasons, if any, why our ancestors developed a taste for spices.