Attenuation of Alcohol Restraint in Demographically Vulnerable Koreans with Alcohol-induced Facial Flushing Phenotype: A Nationwide Population-based Cross-sectional Study (Preprint)

Abstract

Alcohol-induced facial flushing phenotype (flushing) is commonly observed among East Asians. Despite a small intake of alcohol, they experience heightened levels of acetaldehyde, a group-1 carcinogen, which in turn causes unpleasant symptoms such as flushing, acting as a robust protective mechanism against consuming alcohol. However, some individuals with this genetic trait exhibit weakened alcohol restraint, which increases the risk of developing alcohol-related cancers, such as esophageal and head/neck cancer, by more than ten times. Thus, identifying the population characteristics of those who have the flushing trait but cannot refrain from drinking is crucial. However, there is a paucity of studies that have comprehensively investigated the effect of flushing or its genotype on alcohol consumption in a large group of East Asians while controlling for various sociodemographic and health-related variables at a country level. Our aim was to address this research gap.

This cross-sectional study aimed to explore the effect of flushing on drinking behavior in Koreans and to examine whether the effect varies across sociodemographic and health-related factors.

We used data from the Korean National Health and Nutrition Examination Survey 2019–2020 conducted by the Korea Disease Control and Prevention Agency. Our sample comprised 10,660 Korean adults. We investigated the association of 26 variables, including flushing, with drinking frequency and amount. The effect of flushing was investigated with and without adjusting for the other 25 variables using multinomial logistic regression analysis. Additionally, we tested the interaction effect with flushing and conducted a simple effect analysis.

In the flushing group, the odds of each drinking frequency/amount versus “never drank in the past year” (reference) were significantly lower than in the non-flushing group after adjusting for potential confounders at all levels except the lowest contrast (all of OR < 1 and 95% CI did not include the value of one); the odds ratio tended to decrease as the drinking frequency/amount increased. Flushing had notable interactions with other variables. A simple effect analysis showed a diminished alcohol-suppressive effect of flushing on alcohol consumption for specific groups (e.g., those with a low level of education, limited family support, physical labor, or health-related issues).

Our findings suggest that flushing suppresses drinking in Koreans overall but has little or no effect in certain vulnerable populations. Therefore, health authorities should conduct targeted epidemiological studies to assess drinking patterns and disease profiles, particularly regarding alcohol-related cancers, and establish effective preventive measures tailored to this population. Generalizability of these findings to other East Asian communities should also be determined.