The article entitled ‘Explaining variability in sodium intake through oral sensory phenotype, salt sensation and liking’ was published in 2010 by Hayes, Sullivan and Duffy, and focuses on the relationship between sensory phenotype, liking of saltiness and sensitivity to saltiness. The term ‘sensory phenotype’ in this case refers to differences between individuals regarding their sensitivity to a particular bitter compound (PROP) and the amount of taste buds on an individual’s tongue.
This article investigates these relationships with the view to further understand the issues surrounding salt intake and associated health implications. As discussed on the blog before, there are a number of health issues that are associated with high levels of dietary sodium, and as such it is important to investigate any potential causes of heightened consumption.
Participants were tested for sensitivity to salt and their liking in two ways;
- Salt solutions
Participants were asked to rate the intensity of the sensations and their liking of a salt and water solution.
- Chicken broth
Participants were asked to provide intensity and liking ratings for seven chicken broth samples with differing levels of sodium.
This study found that both PROP sensitivity and number of taste buds were associated with greater sensitivity to salt in salt/water solutions. It was found that individuals who found PROP more bitter also found the sodium solutions more salty. Higher levels of perceived saltiness was also found to be associated with lower liking ratings.
Conversely, the testing using a chicken broth base found that while there was a relationship between PROP sensitivity and sodium sensitivity, there was no relationship between taste bud density and any outcomes. This is contrary to previous research that has been done in relation to the number of taste buds an individual has.
Overall, this study suggests that PROP sensitivity and papillae density are linked with intake through liking and sensation rather than directly affecting intake itself. The main finding of this study relates to PROP sensitivity, which is shown below in figure 1. Papillae density appears to be linked with lower liking of high fat and salt foods, and therefore lower intake.
As a final note, the authors suggested that as individuals who are more sensitive to both PROP and salt have been shown to add less salt to their food at the table, it may be that they are able to taste enough saltiness and therefore don’t need to add any additional discretionary salt, whereas individuals who are less sensitive may need to add salt to get the same level of sensation.
Hayes, J., Sullivan, B., Duffy, V. (2010). Explaining variability in sodium intake through oral sensory phenotype, salt sensation and liking. Physiology and Behavior, 100, 369-380.