Dubai, United Arab Emirates (CNN) — A study of about 4 million South Koreans showed that consuming one or two glasses of alcohol a day on a regular basis reduces the odds of developing dementia.
On the other hand, if the amount consumed exceeds the average of two glasses per day, this increases the risk of dementia, according to the study, which was published on Monday in the journal “JAMA Network Open”.
First author Dr. Keun Hye-jeon, assistant professor at CHA Gumi Medical Center at CHA University, Gumi, South Korea, told CNN, “We found that regular light-to-moderate alcohol consumption, as well as reducing alcohol consumption from an excessive level, to moderate is associated with a lower risk of dementia.”
Richard Isaacson, an Alzheimer’s disease researcher and preventive neurologist at the Institute of Neurodegenerative Diseases in Florida, who was not involved in the study, said, “This study is well-conducted, and it’s very robust for including 4 million people, but we have to be careful, even Don’t over-interpret the results.
On the other hand, the US Centers for Disease Control and Control (CDC) found that alcohol use may be a risk factor for breast cancer and other types of cancer, and consuming too much alcohol can contribute to digestive problems, heart and liver disease, high blood pressure, and stroke. stroke, and a weakened immune system over time.
Isaacson pointed out that there are also alerts regarding Alzheimer’s disease. For example, if a person has one or more copies of the APOE4 genetic variant, which increases the risk of Alzheimer’s disease. In that case, drinking is not a good option.
He continued, “Alcohol has been shown to be harmful to the brain in people with this dangerous gene, and about 25% of the US population carries one copy of APOE4.”
Limit alcohol consumption
The new study reviewed the medical records of people covered by the Korea National Health Insurance Service (NHIS), which provides free health check-ups twice a year to insured South Koreans aged 40 and over. In addition to conducting several tests, the researchers asked the participants about their drinking, smoking, and exercise habits.
The study looked at data collected between 2009 and 2011, and categorized people according to their self-reported drinking levels. If someone says they drink less than 15 grams of alcohol per day, they are considered a “moderate” drinker.
In the United States, a standard drink contains 14 grams of alcohol, which is roughly equivalent to 12 ounces of regular beer, 5 ounces of wine, or 1.5 ounces of distilled spirits.
If study participants told doctors they drank 15 to 29.9 grams a day, the equivalent of two standard US drinks, the researchers classified them as “moderate” drinkers. If people said they drank more than 30 grams, or three or more cups a day, the researchers considered them to be “heavy drinkers”.
The researchers also looked at whether people consumed the same amount of alcohol, or adjusted for the amount, between 2009 and 2011, Jeon said.
“By measuring alcohol consumption at two time points, we were able to study the relationship between reduced alcohol consumption, abstinence, regular or excessive drinking, and incident dementia,” he said.
The team then compared that data to 2018 medical records, seven or eight years later, to see if anyone who participated in the study had been diagnosed with dementia.
After adjusting for age, gender, smoking, exercise level, and other demographic factors, the researchers found that people who said they drank at a moderate level over time, about one drink per day, were 21% less likely to develop dementia than people who never drank.
The study found that people who said they continued to drink at a moderate level, or two drinks per day, were 17% less likely to develop dementia.
“One has to be careful when interpreting studies using medical records,” Isaacson said. “It can be fraught with challenges in terms of how diseases are coded and studied.” “Anytime you ask people to remember their behaviour, such as drinking, it leaves room for memory errors,” he continued.
The risks of drinking increase over time
The positive pattern did not continue with increased drinking. The study found that people who drank heavily, meaning three or more drinks per day, were 8% more likely to develop dementia.
If heavy drinkers reduce the moderate level, their risk of developing Alzheimer’s disease decreases by 12%, and the risk of developing dementia from various causes decreases by 8%.
However, Isaacson said, people are not good at judging how much alcohol they drink.
“For example, people don’t really monitor how much wine they drink,” he added. He continued, “They may think they are drinking a standard-sized glass of wine, but it’s actually about a glass and a half at a time. This is no longer low or moderate consumption.”
In addition, many people think they drink alcohol in moderation, and drink it especially on weekends. Studies show that heavy drinking is on the rise all over the world, even among adults.
“If someone drinks 5 drinks on Saturday and Sunday, that’s 10 drinks a week, and that person qualifies as a moderate drinker,” Isaacson said. “For me, this is not the same as having a glass of wine over a five-day-a-week period with a meal, which slows consumption,” he said.
The new study also found that starting to drink at a moderate level was associated with a lower risk of all-cause dementia and Alzheimer’s disease.
However, Jeon noted that “none of the current health guidelines recommend starting with alcohol,” adding that because the study was observational, cause and effect cannot be determined.
“Our findings regarding initiation of moderate alcohol consumption cannot be directly translated into clinical recommendations, and therefore additional studies are warranted to further confirm these associations,” Jeon said.
A study published in March 2022 found that just one pint of beer or a glass of wine per day can shrink the total volume of the brain, with the damage increasing according to the amount of daily drinks.
“I would not personally suggest that anyone start drinking moderate amounts of alcohol if they are abstinent,” Isaacson said. “But the truth is, there is no one-size-fits-all approach to counseling patients about alcohol consumption.”