Cold adaptive thermogenesis following consumption of certain pungent spice principles: A validation study

Abstract

Identifying a means to activate or potentiate thermogenic mechanisms through ingestion of dietary compounds have important implications in cold endurance and survival. Although many reports discuss the thermogenic potential of spices, it is surprising that none of the studies verify whether consumption of spices can improve cold endurance. In this study, we have attempted to evaluate if ingestion of certain spices can activate heat-generating mechanisms in the body such that a fall in. core body temperature (CBT) can be delayed or prevented when faced with a cold challenge. Ten commonly used spices in the Indian cuisine were chosen and 70% ethanol extract of the spices were fed orally to male Wistar rats at a dose of 250mg/kg for a period of 7 days. A change in CBT during cold exposure was recorded before and after treatment. At the end of the experiment, plasma norepinephrine and serum free fatty acid levels were estimated. We observed that among the ten spices, treatment with cinnamon and pepper extracts showed significant improvement in comparison to the control group. Based on evidence in literature and the HPLC-MS analysis from our lab, we hypothesized that the effects of the pepper and cinnamon extracts might be due to their piperine and cinnamaldehyde content respectively. However, no improved endurance was observed when they were administered alone. Poor endurance following depletion of endogenous norepinephrine levels using reserpine indicated its involvement in mediating the heat generating processes. However, it is noteworthy that green tea and spice treated animals exhibited a fall in CBT which was lower than their initial fall. In conclusion, our findings provide experimental evidence that ingestion of spices, viz., pepper and cinnamon, might elicit thermogenic responses such that hypothermia can be delayed or prevented upon cold exposure.