Moderate Alcohol Consumption Linked to Reduced Dementia Risk?

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Moderate Alcohol Consumption Linked to Reduced Dementia Risk? Study of 4 Million Individuals

Moderate Alcohol Consumption Linked to Reduced Dementia Risk? Study of 4 Million Individuals

Disclaimer: This article provides an accurate interpretation of the literature and does not advocate for alcohol consumption.

Dementia presents a significant global health burden with substantial economic and social implications. There are approximately 57.4 million cases of dementia worldwide, and this number is projected to increase to 152 million by 2050.

Despite considerable scientific efforts, there are currently no highly effective treatment strategies to prevent or cure dementia.

It is well-known that alcohol consumption is detrimental to health, increasing the risks of cancer, heart disease, and hypertension. Alcohol consumption is often considered a potentially modifiable risk factor for dementia, but the results in the literature are inconsistent.

Recently, researchers from Seoul National University and Gyeongsang National University in South Korea published a study titled “Changes in Alcohol Consumption and Risk of Dementia in a Nationwide Cohort in South Korea” in the “JAMA Network Open” journal.

The study analyzed data from 4 million individuals in South Korea and found that moderate alcohol consumption was associated with a reduced risk of all-cause dementia. Compared to non-drinkers, light drinkers had a 21% lower risk of dementia, while moderate drinkers had a 17% lower risk. However, higher levels of alcohol consumption increased the risk of dementia, with heavy drinkers showing an 8% increase in risk.

Moderate Alcohol Consumption Linked to Reduced Dementia Risk? Study of 4 Million Individuals

In this study, researchers analyzed the Korean National Health Insurance Service (NHIS) database, which included 3,933,382 participants with an average age of 55, of whom 51.8% were male. At the beginning of the study, none of the participants had dementia. Adults aged 40 and above underwent health examinations in 2009 and 2011, which included the number of days of alcohol consumption per week and the amount of alcohol consumed.

Participants were categorized based on their alcohol consumption: non-drinkers, light drinkers (less than 15 grams of alcohol per day, equivalent to a 350ml can of beer), moderate drinkers (15-30 grams per day), and heavy drinkers (more than 30 grams per day). Participants were also classified based on changes in alcohol consumption levels from 2009 to 2011: non-drinkers, quitters, reducers, maintainers, and increasers. Researchers analyzed the association between alcohol consumption patterns and the incidence rates of all-cause dementia, Alzheimer’s disease (AD), and vascular dementia (VaD).

At the first health examination, 54.8% of participants were non-drinkers, 26.7% were light drinkers, 11% were moderate drinkers, and 7.5% were heavy drinkers.

From 2009 to 2011, 24.2% of light drinkers, 8.4% of moderate drinkers, and 7.6% of heavy drinkers quit drinking. However, 13.9% of non-drinkers, 16.1% of light drinkers, and 17.4% of moderate drinkers increased their alcohol consumption levels.

During an average follow-up period of 6.3 years, a total of 100,282 cases of all-cause dementia, 79,982 cases of Alzheimer’s disease, and 11,085 cases of vascular dementia were recorded.

The study found that moderate alcohol consumption was associated with a reduced risk of all-cause dementia. Compared to non-drinkers, light drinkers had a 21% lower risk, moderate drinkers had a 17% lower risk, while heavy drinkers had an 8% increased risk. Similar results were observed for Alzheimer’s disease and vascular dementia.

Analysis of changes in alcohol consumption levels revealed that reducing alcohol consumption from heavy to moderate or starting light drinking from abstaining was associated with a decreased risk of all-cause dementia, while quitters and increasers showed higher risks of all-cause dementia.

Researchers suggested that the protective effect of moderate alcohol consumption may be attributed to various mechanisms, such as reducing neuroinflammation in Alzheimer’s disease. Regarding vascular dementia, moderate alcohol consumption may be beneficial to the vascular system, increasing platelet function and high-density lipoprotein serum concentrations.

However, excessive alcohol consumption can have various harmful effects through direct mechanisms, such as confirmed alcohol neurotoxicity and malnutrition, as well as exacerbating the pathology of Alzheimer’s disease by enhancing tau protein accumulation.

The authors pointed out that the harms of alcohol outweigh any minor benefits. Early studies have shown that alcohol consumption increases the risks of cancer, heart disease, hypertension, and weakens the immune system.

Researchers also acknowledged limitations, noting that this study cannot conclusively prove that alcohol leads to a reduced risk of dementia, as opposed to other factors such as diet or genetics. For example, alcohol consumption levels were self-reported by participants, which may not be accurate, and non-drinkers tended to be older, which could increase their risk of dementia due to other reasons.

Dr. Percy Griffin, Director of Scientific Engagement at the Alzheimer’s Association, stated that while this study is intriguing and the topic deserves further research, no one should consider alcohol consumption as a method to lower the risk of Alzheimer’s disease or other dementias.

Paper Link: doi:10.1001/jamanetworkopen.2022.54771