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

Abstract 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. 2021, Nat Hum Behav) 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. Because several spices are known to have anticancer effects, we explored, using the same dataset, the hypothesis that natural selection and/or cultural evolution may have favoured spice consumption as an adaptive prophylactic response to reduce the burden of cancerous pathologies. Patterns of spice use in 36 countries, however, are not consistent with a cancer mitigation mechanism: the age-standardised rate of almost all gastrointestinal cancers was not related to spice consumption. Thus, directions other than foodborne pathogens and cancers should be explored to understand the health reasons, if any, why our ancestors developed a taste for spices.