Dementia risk is reduced with minimal alcohol consumption, study finds, but it’s complicated
According to a study of nearly 4 million South Koreans.
However, drinking more than two drinks a day increases that risk, according to the study published Monday in the JAMA Network Open journal.
“We found that maintaining light to moderate alcohol consumption as well as reducing alcohol consumption from high to moderate levels was associated with a decreased risk of dementia,” said the first author. , Dr. Keun Hye Jeon, assistant professor at CHA Gumi Medical Center, CHA University of Gumi, South Korea, in an email.
But don’t rush to the liquor store, experts say.
“This study was well done and is extremely robust with 4 million subjects, but we have to be careful not to overinterpret the results,” said Alzheimer’s disease researcher Dr. Richard Isaacson, preventive neurologist at the Florida Institute of Neurodegenerative Diseases. He did not participate in the new study.
Alcohol consumption may be a risk factor for breast cancer and other cancers, and drinking too much can contribute to digestive problems, heart and liver disease, high blood pressure, strokes and a weakened immune system over time, according to the US Centers for Disease Control and Prevention.
There are also red flags for Alzheimer’s disease. For example, if a person has one or two copies of the APOE4 gene variant, which increases the risk of developing the disease of the mind, drinking is not a good choice, Isaacson said.
“Alcohol has been shown to be harmful to brain outcomes in people with this risk gene – and approximately 25% of the US population carries a copy of APOE4,” he said.
The new study looked at the medical records of people covered by the Korea National Health Insurance Service (NHIS), which offers a free health check twice a year to insured South Koreans aged 40 and older. In addition to doing various tests, the examiners asked questions about each person’s drinking, smoking and exercise habits.
The study looked at data collected in 2009 and 2011 and ranked people based on their self-reported alcohol consumption. If a person reported drinking less than 15 grams (about 0.5 ounces) of alcohol per day, they were considered a “light” 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 drinks in the United States — researchers categorized them as “moderate” drinkers. And if people said they drank more than 30 grams, or three or more glasses a day, the researchers considered them “heavy drinkers.”
The researchers also looked at whether people maintained or changed the amount they drank between 2009 and 2011, Jeon said.
“By measuring alcohol consumption at two time points, we were able to investigate the relationship between reducing, stopping, maintaining, and increasing alcohol consumption and incident dementia,” he said. .
The team then compared that data to medical records in 2018 – seven or eight years later – to see if anyone studied had been diagnosed with dementia.
After adjusting for age, sex, smoking status, exercise level and other demographic factors, the researchers found that people who said they drank moderately over time – about one drink per day – were 21% less likely to develop dementia than people who had never drank.
People who said they continued to drink at a moderate level, around two glasses a day, were 17% less likely to develop dementia, the study found.
“Caution should be taken when interpreting studies using medical records. They may face challenges in how diseases are coded and studied,” Isaacson said. “Anytime you ask people to remember their behaviors, like drinking, it leaves room for memory errors.”
The positive trend did not continue as alcohol consumption increased. People who drank heavily — three or more drinks a day — were 8% more likely to be diagnosed with dementia, the study found.
If heavy drinkers reduced their alcohol consumption over time to a moderate level, their risk of being diagnosed with Alzheimer’s disease decreased by 12% and their risk of dementia from all causes decreased by 8%.
However, people aren’t very good at judging how much alcohol they drink, Isaacson said.
“People don’t really watch their wine pours, for example,” Isaacson said. “They may think they’re drinking a standard sized glass of wine, but it’s actually a glass and a half every time. Drink two of those pours and they’ve had three glasses of wine. It is no longer a light or moderate consumption.
Also, too many people who think they are moderate drinkers drink all weekend. Excessive alcohol consumption is on the rise worldwide, even among adults, studies show.
“If someone drinks five drinks on Saturday and Sunday, that’s 10 drinks a week, which would be considered moderate drinking,” Isaacson said. “For me, it’s not the same as having a drink of wine five days a week with a meal, which slows consumption.
The new study also found that starting to drink at a moderate level was associated with a decreased risk of all-cause dementia and Alzheimer’s disease, “which, to our knowledge, has never been reported in previous studies. “, wrote the authors.
However, “none of the existing health guidelines recommend starting to drink alcohol,” Jeon said, adding that since the study was observational, cause and effect cannot be determined.
“Our findings regarding the initiation of light drinking cannot be directly translated into clinical recommendations, warranting additional studies 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 a day can reduce overall brain volume, with damage increasing as the number of daily drinks increases.
On average, people between the ages of 40 and 69 who drank a pint of beer or a 6-ounce glass of wine a day for a month had brains that looked two years older than those who drank just one. half a beer, according to this previous study.
“I’ve never personally suggested anyone start drinking moderate amounts of alcohol if they’re sober,” Isaacson said. “But there’s really no one-size-fits-all approach to counseling a patient about alcohol use.”