A Comparative Study of Whole-Mouth Taste Thresholds between North Korean Refugees and South Koreans

Kim, Eun Young; Kim, Yiseul; Lee, Youngjoo; Rhyu, Mee Ra

Abstract

BACKGROUND AND OBJECTIVES
Since Korea has been divided into two countries over 60 years ago and differences has gradually developed between the two, an influx of North Korean refugees to South Korea have soared over the past 20 years. Their complaints regarding taste intensity, particularly about strong sweetness of foods, are common after entry into South Korea. Because a long-term over-exposure or restriction to some taste stimuli causes profound alterations in corresponding taste sensitivity in humans, we hypothesized that sugar restriction, which remains common in North Korea, has influenced sweet sensitivity of North Koreans.
SUBJECTS AND METHOD
To test this hypothesis, we assessed the taste stimuli recognition and detection thresholds of both young adults North refugees and South Koreans using a 1-mL whole-mouth gustatory test applied to a series of sweet, bitter, sour, and salty solutions.
RESULTS
As expected, the cumulative curve of the recognition threshold for sucrose shifted to the left and the mean recognition threshold for sucrose was significantly lower (0.5357% vs. 0.7393%, p=0.044) for North refugees than for South participants. On the other hand, the recognition threshold for salt was significantly higher (0.2174% vs. 0.1212%, p=0.027) in North refugees. No differences on the recognition taste sensitivity for quinine hydrochloride and citric acid were observed.
CONCLUSION
The findings documented in the present study indicate that a prolonged food deficit seems to have changed the taste sensitivity of healthy North Korean refugees. The altered taste sensitivity was most pronounced for sweet and salty tastes, and lasted up to 3.5 years after the refugees left North Korea.