Ten guidelines for a healthy life: Korean Medical Association statement (2017).
December 15, 2017 148 p (in English)

doi: https://doi.org/10.26604/979-11-5590-078-9-93510-2

Drinking in Moderation

Drinking in Moderation

Stop peer pressure to drink, especially if someone's face turns red after only one shot


◆ Background

Koreans tend to have a genetically lower alcohol metabolism than Westerners, and are thus more vulnerable to alcohol. This fact is often ignored, even though it poses a severe health risk to Korean society, which is aggravated by the after-work drinking culture, where the pressure to drink is common. Even those with a relatively good alcohol metabolism show aldehyde toxicity symptoms after consuming the equivalent of half a bottle of soju (Korean distilled beverage).

◆ Purpose

1. To identify those who are extremely alcohol-sensitive and advise them not to drink.

2. To suggest a standard amount of alcohol consumption for occasional drinkers.

3. To help frequent drinkers reduce their alcohol consumption and understand the health risks of regular drinking.

◆ Contents

1. “Cheers, except for those whose faces turn red after only one shot!”

Those who have a flush reaction to one shot of soju or one glass of beer (180 mL), or who had such a reaction when first exposed to alcohol in their late teens or early 20s, are deemed to have a genetically weak alcohol metabolism. These people should not drink alcohol at all, nor should they be invited to.

2. The zero-hangover formula: Always drink slowly and moderately over a period of 2-3 hours with water and/or food

Occasional drinkers who drink 1-3 times a month are recommended to consume alcohol with water and/or food slowly over 2-3 hours to prevent hangovers the following morning. The standard alcohol limit for males is 3-4 shots of soju, 2 cans of beer, or 2 glasses of wine, while 2-3 shots of soju, one can of beer, or one glass of wine is considered the cap for females.

3. When is your alcohol-free day? Frequent alcohol consumption increases the risk of cancer!

Frequent drinkers are advised to designate alcohol-free days to reduce their alcohol consumption.

◆ Expected impact

To help protect those vulnerable to alcohol and promote a healthy drinking culture.

Keywords: Ethanol, Acetaldehyde, Aldehyde dehydrogenase, Microsomal ethanoloxidizing system, Oxidative Stress

Best practices to follow

1. Stop peer pressure to drink! Never force people to drink, especially those whose faces turn red after only one shot!

2. The zero-hangover formula: Always drink slowly and moderately over a period of 2-3 hours with water and/or food

3. When is your alcohol-free day? Frequent alcohol consumption increases the risk of cancer!

Fact Sheet ➊

Stop peer pressure to drink! Never force people to drink, especially those whose faces turn red after only one shot!

Mr. Kim, a Korean businessman in his early 30s, is afraid of company dinner outings. His senior colleagues always insist he drink with them over dinner. He has a flush reaction all over his face and body after just one shot of soju, accompanied by a rash and skin irritation in severe cases (Fig. 2.1). However, his seniors continue to force more drinks upon him, claiming that they saw on TV that “a small amount of wine is said to prevent aging and is good for your cardiovascular system and skin.” They also believe that he should drink more to increase his tolerance for alcohol. Mr. Kim often feels a headache, escalated heartbeat, and nausea after drinking.

Figure 2.1

Facial flushing after a minimal amount of alcohol.

Before (left) and after (right) drinking alcohol. A 22-year-old Asian male with a less functional aldehyde dehydrogenase enzyme (an ALDH2 heterozygote) due to genetics. (Adapted from Brooks PJ et al [1])


Why does this happen to Mr. Kim?

Why does even a small amount of alcohol affect him this way? Ethanol, the intoxicating substance in alcoholic drinks, is first converted to acetaldehyde, which is toxic, by alcohol dehydrogenase (ADH). Then, in the second step, acetaldehyde is converted to acetate by aldehyde dehydrogenase (ALDH). A less functional ALDH enzyme leads to increased acetaldehyde accumulation inside the body, which causes facial flushing, headaches, and an increased heart rate [1,2]. Those with a severe flushing reaction in response to even small amounts of alcohol are considered to have a genetic ALDH deficiency, which causes their bodies to rapidly accumulate a large amount of toxic acetaldehyde even after drinking only a small amount (Fig. 2.2). The alcohol flush reaction is more common among East Asians than Westerners, and has been reported to affect 35%-37% of Korean, Chinese, and Japanese people [1,3]. Those who experience a decrease in this symptom with age, but experienced the alcohol flush reaction when first exposed to alcohol in their late teens or early 20s, are also considered to have this condition [2]. The Japanese, Chinese, and Korean populations are estimated to have this condition at rates of 45%, 30%-33%, and 30%, respectively. In contrast, it is found significantly less often in other Asian populations, including Indians, Filipinos, and Malaysians. The condition is rare among Europeans, North Americans, and Africans [3].

Figure 2.2

Comparison of blood acetaldehyde concentrations over time between adults with and without facial flushing after consuming 3 shots of soju. (Adapted from Peng GS et al [4])


An individual who inherits just one dysfunctional allele of the gene from one of his or her parents will develop ALDH deficiency.

Acetaldehyde is the key driver of acute and painful hangover symptoms. It has also been established to be Class 1 carcinogen to human according to WHO, that causes malignant tumors upon prolonged exposure. Therefore, if you urge people whose skin easily flushes after one shot of alcohol to drink, you are essentially forcing them to absorb a glass full of carcinogens [1,4,5].

Unfortunately, this ‘secret’ regarding alcohol breakdown in those of East Asian descent has not been well advertised to the public. Those who are particularly defenseless against alcohol are unprotected in modern Korean drinking culture. Modern Korean social and organizational culture has a liberal attitude toward alcohol. Along with this attitude, people are exposed to frequent depictions of binge drinking in mass media and the notoriously rampant practice of forcing people to drink at after-work company dinner events [1].

In fact, these people should not even consume a tiny shot of alcohol for the sake of their health, let alone be pressured to drink with others.

As a conclusion, I would like to suggest the following toast:

“Cheers, except for those whose faces turn red after only one shot!”

Fact Sheet ➋

The zero-hangover formula: Always drink slowly and moderately over a period of 2-3 hours, with water and/or food

Standard alcohol consumption

Males (per session) Females (per session)

3-4 shots of soju 2-3 shots of soju

(2 cans of beer or 2 glasses of wine) (1 can of beer or 1 glass of wine)

Individual tolerances for alcohol are difficult to define, but standard healthy drinking limits are considered to be amounts that do not bring any discomfort to an individual the following morning. An occasional drinker who consumes alcohol 1-3 times a month or once a week or less is advised to follow the above recommendations and drink slowly over a 2- to 3-hour period in order to stay safe and prevent any discomfort the next morning [6-8]. One shot of soju is defined as 50 mL of soju with 20% alcohol by volume (ABV) for males, the equivalent of four-fifths of a regular soju shot glass, and 40 mL of 18% ABV soju for females, equivalent to three-fourths of a shot glass. One can of beer is defined as 355 mL of 4.5% ABV beer, and one glass of wine as 150 mL of 12% ABV wine, approximately half of a standard wine glass.

High-risk drinkers are males who consume 12 shots or more of 18% ABV soju a day or females who drink 10 shots or more of 18% ABV soju a day. This is equivalent to six 355-mL cans of 4.5% ABV beer for men and 5 cans of the same beer for women [7]. Binge-drinking is consuming the same amount of alcohol over 2 hours of time. Even a single round of such high-risk drinking or binge drinking may lead to acute arrhythmia and coronary artery disease requiring hospitalization [7]. Such drinking habits are also linked to various health and social issues, including sexually transmitted infections, unwanted pregnancies, violence, injury, and drunk driving.

Inside the body, alcohol is first converted to acetaldehyde and then converted to acetate by the ALDH enzyme. Frequent drinking promotes a different set of enzymes, collectively known as the microsomal ethanol oxidizing system, which metabolizes more alcohol and acetaldehyde, corresponding to an increased drinking capacity. However, occasional drinkers who drink 1-3 times a month may experience intoxication from an accumulation of acetaldehyde once they consume a high level of alcohol, even if they have normal ALDH function [8,9]. This is called an alcohol hangover (Fig. 2.3).

In general, alcohol intake around 8-10 PM makes you feel a little tipsy but energized. However, 6 hours later, around 3-4 AM, even if you are mentally sober as your blood alcohol level drops to 0, you are still intoxicated from the acetaldehyde, and hangover symptoms may be at their worst, as your acetaldehyde level peaks [9,10]. An individual’s tolerance for alcohol depends on physique, age, gender, fatigue, and health conditions, as well as the frequency of alcohol consumption. The average tolerance for alcohol of a healthy 60-70 kg male occasional drinker who drinks 1-3 times a month is 4-5 shots of 18% ABV soju [4,7,8,10].

The problem lies in the fact that Korean drinking culture discourages people from limiting their alcohol consumption to the “healthy drinking limit” standards. A senior colleague who frequently drinks and has a highly active microsomal ethanol oxidizing system is likely to encourage a junior coworker to drink more alcohol than he or she can tolerate. In reality, this means forcing your subordinates to consume a liquid toxin, only to have them be incapacitated for work the next day.

Figure 2.3

Metabolism of alcohol and substances that cause hangovers

People with a good aldehyde metabolism may still suffer from aldehyde toxicity upon consuming half a bottle of soju or more. (Provided by PICO Entech Co. Ltd.)


Fact Sheet ➌

When is your alcohol-free day? Frequent alcohol consumption increases the risk of cancer!

It is recommended to limit your number of drinking sessions to once a week, but men who drink as frequently as 2-3 times a week should make it a priority to limit their total weekly consumption of alcoholic drinks to less than 2 bottles of 18% ABV soju (1 bottle = 360 mL) [6,11]. This corresponds to eight 355-mL cans of beer with a 4.5% ABV or seven 150-mL glasses of wine (half a regular wine glass) containing 12% ABV. If the total amount of alcoholic drinks consumed in a week is close to 2 bottles of soju, it is recommended that a person consume that amount over at least 3 days. Women should consume no more than half of the standard amount for men [11].

Frequent drinking episodes may increase one’s chances of developing mouth, throat, larynx, colon, liver, and breast cancer, even if you drink a moderate amount per session. The more you drink, the higher the risk of cancer. Those who suffer facial flushing have a markedly higher risk of esophageal, head, and neck cancer than those who do not [1,8]. An effective way to reduce alcohol consumption is to plan self-designated alcohol-free days every week and stick to your plan [6].

*The percentage of alcohol for each alcoholic drink is measured by volume (ABV).



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[1] Contributing associations and organizations:

Korean Society of ALDH

Korean Society of Cancer Prevention

Contributing experts:

Se-Young Choung, Department of Preventive Pharmacy and Toxicology, College of Pharmacy, Kyung Hee University

Jong Sung Kim, Department of Family Medicine, Chungnam National University Hospital

Hee Man Kim, Department of Internal Medicine, Yonsei University Wonju College of Medicine and Wonju Severance Christian Hospital

Jung Eun Lee, Department of Food and Nutrition, Seoul National University

Yu Jin Paek, Department of Family Medicine, Hallym University Sacred Heart Hospital

Cheol Min Shin, Department of Internal Medicine, Seoul National University Bundang Hospital