K-pop singer Kim Se-jeong quits drinking after daily habit impairs training

Singer and actress Kim Se-jeong said she has quit drinking after a nightly alcohol habit escalated and began impairing her cognitive performance during daily training for I.O.I's first full group reunion in 10 years, she disclosed on a South Korean variety show Monday.

The admission, reported by The Korea Times, illustrates how even moderate daily drinking can disrupt deep sleep and accelerate brain aging, according to health researchers — a pattern that can catch up with performers maintaining intensive training schedules.

Kim, a member of the K-pop group I.O.I, opened up about her relationship with alcohol on the SBS variety show "But Seriously," according to The Korea Times. When host Lee Soo-ji noted that the members could now drink together as adults, Kim replied simply: "I really love alcohol."

She described herself as a moderate drinker driven by ritual. "I'm not the type to binge drink, but at the end of the day, having a drink makes me feel like I worked hard today," Kim said. She added that the nightly ritual had grown harder to control: "I usually drink about two cans of beer. Then alcohol starts calling for more alcohol. I'll think, 'Maybe I should try a little whiskey too,' and before I know it, I'm pouring more."

The habit eventually affected her work. "My sense of reward was huge. After practice, no matter how tired I was, I would always have a drink before bed. Lately I've been practicing every day, and because I was drinking daily, my brain just stopped working. I realized this really wasn't good. For the sake of my training, I decided I needed to quit drinking. I'm currently trying to stop," Kim said on the show.

The Korea Times cited research from the National Institute on Alcohol Abuse and Alcoholism and UK Biobank data showing that daily drinking can impair judgment, memory and concentration, reduce the quality of deep sleep and speed up brain aging. The article also noted that many people of East Asian descent carry a variant of the ALDH2 gene that slows the breakdown of acetaldehyde — a byproduct of alcohol metabolism — raising health risks even at lower consumption levels. Facial flushing after drinking is a common sign of this variant, the Times reported.

Kim's comments come as I.O.I prepares for what the group's fans are calling a landmark comeback — the first time all members have reunited since the group disbanded roughly a year after its 2016 debut through the reality competition "Produce 101."

Kim said she is actively working to stop drinking as I.O.I readies for their full group comeback.