If you’re concerned that drinking alcohol increases your risk of dementia as you age, a large new study from South Korea may provide insight. This starts from the idea that in general, reducing your alcohol consumption is a good idea.
“Maintaining light to moderate alcohol consumption is associated with a decreased risk of dementia, whereas excessive alcohol consumption increases the risk of dementia,” said the study’s first author, Dr. Dr. Keun Hye Jeon, to NPR.
Part of the study’s findings seem to have taken many people by surprise: it found that while going from heavy to moderate alcohol consumption reduced the risk of dementia, so did “the initiation of a moderate consumption.
Study reveals complex interaction between alcohol and health
“Those who drink alcohol within the recommended limits are not advised to quit on the grounds of reducing dementia risk,” Jeon said, “although reducing alcohol consumption may provide other benefits for health”.
Compared to people who didn’t change their drinking habits, Jeon and his colleagues found that two groups had an increased risk of dementia: drinkers who increased their intake and people who quit completely.
“People who quit, regardless of their level of alcohol consumption, showed a higher risk of all-cause dementia compared to those who maintained the same level of alcohol consumption,” according to the research paper. .
This aspect of the results has been talked about a lot, as people try to analyze whether it could represent true cause and effect – and a possible new data point in their own decisions about drinking. But the researchers warn that the higher dementia risks of people who quit drinking in their study “are believed to be primarily attributed to the sick dropout effect, which is defined as a person quitting (or reducing) a certain hazardous activity due to health problems.”
In other words, they may have stopped drinking because their health deteriorated, rather than their health deteriorated because they stopped drinking.
So what can drinkers do to limit their risk of dementia?
When asked what surprised the researchers the most about the results, Jeon said it was the large drop in risk when people reduced their alcohol intake, noting that heavy drinkers who moderated their drinking were associated with an 8% lower risk of all-cause dementia, and a 12% lower risk of Alzheimer’s disease.
“For the prevention of dementia, light to moderate drinkers should curb the increase in their alcohol consumption, while heavy drinkers should reduce it,” said Jeon, assistant professor of family medicine at CHA University of Gumi.
“People who do not currently drink alcohol should not be encouraged to start as a way to reduce the risk of dementia,” she added.
Alcohol is known to damage brain cells and impair memory and other functions. Current US dietary guidelines urge adults to “drink in moderation by limiting consumption to 2 drinks or less per day for men and 1 drink or less per day for women”.
According to the researchers, one of the main findings of the study is that it suggests that even small reductions in alcohol consumption can help reduce the risk of dementia.
The study included millions of adults
To search for potential associations between alcohol consumption and dementia outcomes, the researchers relied on data from Korea’s National Health Insurance Service. The government-administered insurer offers free biannual health checks to anyone insured aged 40 and over.
The study included nearly 4 million South Koreans – a specific cohort of adults who underwent back-to-back NHIS health exams in 2009 and 2011. The exams include a medical history and personal habits questionnaire, including alcohol consumption, smoking and exercise, as well as laboratory tests and demographic data. data.
The research team classified people into four drinking categories: none; soft (minus one glass a day); moderate (one to two glasses a day) and heavy (more than two glasses a day).
In the United States, a standard drink is considered to contain 14 grams (0.6 ounces) of pure alcohol, slightly less than the 15 grams used in the study. This is equivalent to a 12 ounce beer at 5% alcohol, a 5 ounce glass of wine at 12% alcohol, or 1.5 ounces of 80 degree alcohol.
The researchers also sorted people by whether they had stopped, reduced, maintained or increased their alcohol consumption. Then, starting a year after the second health check, the researchers counted the members of the cohort who had been diagnosed with dementia through the end of 2018.
The “abandoned sick” effect
“The sick dropout effect is based on the assumption that disease onset and changes in health status lead to cessation of alcohol use,” Jeon said, “so the risk for former drinkers is higher than that for abstainers.
In the study, former drinkers were mostly included in the non-drinking control group. But, she added, “the general poor state of health of former drinkers may lead to an overestimation of the protective effect of alcohol consumption.”
The study authors attempted to compensate for this dynamic in several ways, but “the sick dropout effect remains a source of potential bias,” they wrote.
Another complicating factor is socioeconomic status. The study found that people who quit drinking tend to be older and have lower incomes than those who maintain the same drinking habits. On the positive side, people who quit smoking tended to be non-smokers and were more likely to exercise regularly.
The Korean study also relied on people to report their own health habits, which the researchers acknowledge as a limitation.
What does science say about alcohol consumption?
Heavy drinking and binge drinking are linked to chronic liver disease, high blood pressure, several types of cancer and a range of other health problems, according to the CDC. Excessive alcohol consumption is also associated with violence, accidental death and injury, and damage to the developing fetus.
Outside of the US, some recent advisories are stricter. A large international study on The Lancet concluded in 2018 that “the safest level of alcohol consumption is zero”. And last month, Canada’s new updated guidelines caused a stir when they concluded that any level of alcohol consumption carries a risk and that people should limit themselves to two standard drinks or less per week.
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