Published in Applied Research
Modifying the perception of saltiness using a pungent component of chilli pepper

High salt consumption has been associated with an increased risk of hypertension and cardiovascular events. Whilst there are a number of strategies which promote salt reduction, scientists are reporting that traditional cooking habits and taste can "dampened the effectiveness of salt reduction at the population level."  A study published in Hypertension has investigated an alternative strategy of reducing salt intake by modifying the perception of saltiness, using a pungent component of chilli pepper, capsaicin. Previous research has found that capsaicin also has a protective role against cardiometabolic diseases.

The study by Zhu et al. recruited 606 Chinese adults aged 18-65 years and determined the participants preferences for salty and spicy flavours.  The participants were asked to identify from a number of solutions that contained increasing amounts of capsaicin (1, 3, 5 and 7 µmol/L) which they preferred. They were also given a salt perception test, where they were asked to identify solutions which contained salt at various concentrations of 0, 10, 30, 50 and 75 mmol/L and a salt-threshold test where they had to stipulate which solutions containing high levels of salt (500, 750, 1000, and 1500 mmol/L) they could tolerate. Those who had a preference for capsaicin of 1 or 3 µmnol/L were categorised as low, 5 µmnol/L medium and 7 µmnol/L high.  The participants also completed a diet questionnaire where they reported on salt and spicy food intake, and blood pressure and urinary sodium excretion was measured.  Zhu et al. also used imaging techniques to look at two regions of around 60 participants' brains, the insula and orbitofrontal cortex (OFC), known to be involved in salty taste. Zhu et al. examined "brain metabolism changes in response to a salt stimulus in individuals with high salt consumption" and "subsequently addressed whether changes in salt-induced metabolic activity may be modified by capsaicin administration." The team further investigated the findings in rodent models, by giving mice four types of solutions (deionised water, 200 mmol/L NaCI, 150 mmol/L NaCI and 150 mmol/L NaCl with 0.5 µmol/L capsaicin) and examining the mice brains.

Zhu et al found that compared to those who least enjoyed spicy foods, participants with a high spicy preference had 8 mm Hg lower systolic and 5mm Hg lower diastolic blood pressure; and consumed less salt than participants who had a low spicy preference. They state "high salt intake and salt preference were closely correlated with increased brain activity in the insula and OFC of the participants. Capsaicin administration increased activation of the insula and OFC."  The authors said that this increased activity likely makes people more sensitive to salt so that they can enjoy food with less of it.  Zhu et al report that similar findings were also found in the mouse study with "OFC activity closed associated with salt preference and salty-taste information processed in the OFC was affected in the presence of capsaicin." 

In conclusion the authors discuss the limitation of the study, noting all the participants are from China, so further research is needed to determine if these findings may be generalised to other countries. However they state that "enjoyment of spicy foods may significantly reduce individual salt preference, daily salt intake and blood pressure by modifying the neural processing of salty taste in the brain."


Leave a comment

Copyright © 1998-2022 Chiriotti Editori srl Tutti i diritti riservati
Viale Rimembranza, 60 - 10064 Pinerolo - To - Italy - P.IVA e C.F. 01070350010 - Tel. +39 0121.393127 - email | Disclaimer