Forget dietary advice, scientists say salt reduction strategies should start targetting the brain
The research from China also used brain molecular imaging study to reveal that the preference for more salt is associated with increased activity in several brain regions, including the insula, orbitofrontal cortex (OFC), and parahippocampus.
The researchers carried out a multi-centre, random-order, double-blind taste study with 537 people, both overweight/obese and normal weight, to investigate salty taste and salt intake at the population level.
“We showed that overweight/obese individuals were prone to consume a higher daily salt intake (2.0 g/day higher compared with normal weight individuals after multivariable adjustment,” they wrote in the journal Cellular Physiology and Biochemistry.
“Furthermore they exhibited reduced salt sensitivity and a higher salt preference.”
Reducing high salt intake is vital for preventing hypertension and obesity-related cardiovascular events.
Alter preferences
Currently recommendations for dietary sodium restriction and the use of NaCl substitutes are suffering from poor compliance at the population level.
“Modifying the salty preference might be an alternative strategy for reducing high salt intake,” added the researchers
“Palatability is the consequence of stimulation of brain reward pathways, which indicates that individual’s salty preference might be associated with the neural hedonic properties of the salted foods. In this study, we hypothesized that alterations in brain activity in response to salty taste are responsible for high salt intake in obese individuals.”
Investigations into the changes in the salty taste response of the brain by PET/CT scanning showed increased activity in the orbitofrontal cortex and parahippocampus.
“Interestingly, the OFC and parahippocampus can retain the food memories that interact with the reward–based decision-making process, which may be involved in food-seeking behaviours.
“Our results potentially provide physiologic insights indicating that overweight/obesity individuals develop a less adverse reaction to high salt intake and a more hedonic response to salty taste than normal weight individuals,” they added.
They concluded that the study provided insights for reducing daily salt intake in overweight/obese individuals by modifying the neural processing of salty taste and the reward circuits for salty preference in the brain.
Source: Cellular Physiology and Biochemistry.
DOI: 10.1159/000484122
‘Enhancement of neural salty preference in obesity”
Authors: Qiang Li, et al.
