Moderate alcohol consumption linked to lower dementia risk

Maintaining a mild to moderate level of alcohol consumption was associated with a decreased risk of dementia, according to a study published in JAMA Network Open.

Additionally, lead study author Keun Hye Jeon, MD, of the department of family medicine at Cha Gumi Medical Center, Cha University in Gumi, South Korea, and colleagues found that a change in alcohol consumption from a heavy to moderate level or the introduction of mild alcohol consumption were both linked to a lower risk of all-cause dementia and Alzheimer’s disease.

“Currently, more than 57 million people live with dementia worldwide, and this number is expected to increase to more than 152 million by 2050,” Jeon and colleagues wrote. “Alcohol consumption is generally considered as a potential modifiable risk factor for dementia, but the results in the literature are not completely consistent.”

The retrospective cohort study, which included 3,933,382 participants (mean age, 55 years; 51.8% men) from the National Korean Health Insurance database, explored the connection between alcohol consumption patterns and the occurrence of all-cause dementia, vascular dementia and AD. Participants were aged 40 years and older and underwent a national health examination in 2009, with a second in 2011. To determine hazard ratios and 95% confidence intervals for the association between alcohol consumption and dementia incidence, the researchers used Cox proportional hazard regression analyses.

Newly diagnosed vascular dementia, AD or other dementia served as the study’s primary endpoint.

Daily alcohol consumption less than 15 g was defined as mild, 15 g to 29.9 g was moderate, and 30 g or more was heavy, whereas a level of “none” was defined as 0 g per day.

The researchers reported that 2.5% of participants had all-cause dementia, 2% had AD, and 0.3% had vascular dementia after a mean 6.3 years of follow-up after a 1-year lag period.

According to the study, there was a 21% lower risk for all-cause dementia among participants who sustained mild alcohol consumption (adjusted HR = 0.79; 95% CI, 0.77-0.81) and a 17% lower risk among those who sustained moderate alcohol consumption (aHR = 0.83; 95% CI, 0.79-0.88) compared with participants who sustained nondrinking. Those who sustained heavy drinking, however, experienced an 8% increased risk of all-cause dementia (aHR = 1.08; 95% CI, 1.03-1.12). The researchers reported similar patterns for AD and vascular dementia.

Nondrinkers who initiated mild alcohol consumption were found to be at a lower risk for all-cause dementia (aHR = 0.93; 95% CI, 0.9-0.96) and AD (aHR = 0.92; 95% CI, 0.89-0.95) when compared with those mild drinkers who sustained their consumption level. Those who decreased alcohol consumption levels from heavy to moderate also had an 8% lower risk of all-cause dementia (aHR = 0.92; 95% CI, 0.86-0.99) and a 12% lower risk of AD (aHR = 0.88; 95% CI, 0.81-0.95).

Compared with those who sustained their drinking level, those who quit drinking and those who already drank and increased their level of alcohol consumption all experienced an increased risk of all-cause dementia, according to the study.

“Our analyses indicate that maintaining mild to moderate alcohol consumption is associated with a decreased risk of dementia, whereas maintaining heavy drinking is associated with an increased risk of dementia,” Jeon and colleagues wrote. “Notably, our analyses stratified by the initial amount of alcohol consumption indicate that reduction of drinking from a heavy to a moderate level and initiation of mild drinking were associated with a decreased risk of all-cause dementia and AD.”