Change in facial blood flow before (left) and during (right) the consumption of consommé in a participant who liked the taste of the soup. Red areas indicate greater blood flow and blue areas lower blood flow. (Photo courtesy of the Tokyo Institute of Technology)

2014-1-13 | News Asia Pacific

TOKYO, Japan: Japanese researchers have identified new links between the palatability of various tastes and circulation in different parts of the face. In a recently published study, they found that tastes perceived as pleasant by the study participants increased blood flow around the eyes, while bitter tastes influenced circulation in other facial areas.

In order to examine whether various types of taste stimuli in the oral cavity cause changes in facial skin blood flow, 15 healthy participants (11 males and 4 females) were given samples of sweet chilli sauce, orange juice, bitter tea, coffee and soup. They retained the fluids in their mouths for 30 seconds before swallowing. Afterwards, the participants were asked to rate the tastes with regard to palatability.

Throughout the experiment, the researchers collected skin blood flow data from the participants’ forehead, eyelids, nose and cheek using laser speckle flowgraphy before and during ingestion of the fluids. 

They found that blood flow in the eyelids increased significantly in response to chilli sauce, orange juice and soup, whereas blood flow in the forehead, nose, and cheek decreased in response to bitter tea. “These results suggest that the facial circulatory response reflects the degree of palatability of foods,” the researchers concluded.

The study, titled “Palatability of tastes is associated with facial circulatory responses”, was published online on 5 January in the Chemical Senses journal ahead of print. It was conducted at Tokyo Institute of Technology in collaboration with the Prefectural University of Hiroshima and Kyushu University in Fukuoka.