In the past, this was how office workers in Korea operated. The so-called “owner” of the company made all the decisions, while the rest of the organization simply followed along. The rapid expansion of the manufacturing industry demanded long working hours and minimal sleep. The physical and mental hardships were often dulled by legalized substances such as alcohol and tobacco.

This method of stress relief is no longer effective in today’s knowledge-driven, competitive society. Daily alcohol consumption significantly impairs the frontal lobe, which governs high-level decision-making, and the hippocampus, responsible for retaining long-term memories. Over time, the entire brain shrinks. In a world where split-second decisions determine an organization’s survival, alcohol-induced cognitive decline severely compromises judgment.

The molecular biology behind alcohol’s role in accelerating aging is well documented, with its effects on the nervous system being particularly significant. Previously, neurodegenerative diseases such as alcoholic dementia were believed to occur only after years of heavy drinking. However, modern imaging techniques reveal that even small accumulations of alcohol can accelerate brain aging. Notably, the rapid volume loss in the frontal lobe and hippocampus directly impairs decision-making and memory retention while reducing the ability to grasp complex issues. Additionally, overall brain stress increases, leading to poor impulse control and a tendency to lose temper easily. This often results in illogical or poorly considered decisions.

Our brain’s preference for alcohol can be understood through an evolutionary lens. The “drunken monkey hypothesis” suggests that our ancestors evolved to recognize the trace amounts of alcohol in naturally fermented fruit as a valuable energy source, much like the human preference for sweet and fatty flavors. However, the natural alcohol content in forest berries was only about 1 percent. In contrast, modern industrial societies have developed methods to produce alcohol in concentrations far beyond what occurs in nature. This parallels the way refined sugar and processed foods contribute to obesity.

The issue lies in our country’s permissive drinking culture, which is severely compromising brain health. According to the 2021 National Health and Nutrition Examination Survey, 27.9 percent of men in their 40s engage in high-risk drinking—defined as consuming more than seven drinks per occasion and drinking more than twice a week. This far surpasses the Western standard for moderate drinking, which is limited to three drinks per occasion. Such high-risk drinking accelerates brain aging, leaving alcohol-dependent individuals in their 60s with a brain age 12 years older than their peers. Even more alarming is that “light” drinking—such as consuming one barrel of rice wine daily for three months—can age the brain by over six years.

The dangers of alcohol become even more apparent when examining how it functions in the body. Alcohol acts more like an organic solvent—similar to bond or thinner—than a selective sedative or sleeping pill. For example, a 70-kilogram man drinking just one can of beer can reach a blood alcohol level of 0.03 percent, a state associated with slurred speech and reduced inhibitions. At a level ten times higher, 0.3 percent, maintaining an open airway becomes impossible, posing a life-threatening risk. Moreover, continuous alcohol consumption directly damages nerve cells, triggers widespread inflammation throughout the body, and disrupts the stress hormone system.

Even more concerning is the impact of alcohol on sleep quality. After drinking, your brain does not rest properly, even if you sleep for the same duration. Alcohol alters the structure of sleep, significantly reducing deep sleep and disrupting REM sleep patterns. This results in a state akin to chronic sleep deprivation, impairing judgment, concentration, and memory.

Alcohol also stimulates the release of the stress hormone cortisol, which raises the risk of cardiovascular disease. Sleep and stress management are two of the most crucial health factors for leaders in today’s world, and frequent alcohol consumption worsens both. This is why I compare falling asleep drunk to “scraping your frontal lobe with a razor blade.”

At this point, it is undeniable that the widespread cognitive impairment caused by alcohol can lead to poor decision-making, which can have profound consequences for the future of the nation and companies. Despite these clear harms, Korea remains remarkably tolerant of alcohol. There are even precedents for “drunkenness reduction,” where the penalty for committing a crime while intoxicated is lessened. But if the result is an unnecessary war or a foreign exchange crisis, can we truly afford to take such consequences lightly?

Leaders today must be more alert and clear-headed than ever before. With technology advancing exponentially and the marketplace growing increasingly complex, they face constant pressure to make critical decisions that shape the survival and prosperity of their organizations. The role of a leader has evolved from simple managerial oversight to creative problem-solving and strategic insight. In this environment, alcohol-induced cognitive impairment is not just a health issue; it can pose a serious risk to the future of an organization. That’s why, whenever I speak to leaders in our society, I emphasize that the more you are in a position to make decisions that impact the fate of your organization, the more important it is to keep your brain clear.

We must remember that it is only when you can build yourself up that you can truly lead a nation and govern the world. Sobriety should not be viewed merely as a form of healthcare, but as a fundamental virtue that helps keep the brain clear and sharp.

Jung Hee-won, a geriatric physician at Asan Medical Center, graduated from Seoul National University College of Medicine and trained at Seoul National University Hospital. During his med-school days, while practicing the horn, he realized the importance of muscle maintenance and became interested in sarcopenia. His main research interests include frailty, sarcopenia and establishing age-friendly health systems for acute hospitals. This column was originally published in Chosun Ilbo in Korean on December 11, 2024. -- Ed.