Objectives This research intends to determine how drinking behaviour, such as episodic heavy drinking, is related to cognitive performance in middle-aged and old-aged people in South Korea.

Methods A cohort data of 5157 adults, age 45 years or older, with normal cognitive function (the Korean version of the Mini-mental state examination (K-MMSE) ≥24) at baseline (2006), was derived from the Korean Longitudinal Study of Aging. Alcohol drinking behaviour was assessed using the CAGE (Cut down, Annoyed, Guilty, Eye-opener) questionnaire. The relationships between baseline drinking behaviour (in 2006) to the extent of cognitive decline (between 2006 and 2012) and development of cognitive impairment (in 2012) were assessed.

Results Individuals with problematic drinking behaviour at baseline experienced a faster decline in cognitive function than those with non-problematic drinking (p<0.05) during 6 years of follow-up, especially among those with relatively lownormal K-MMSE score (24–26) at baseline (p<0.05). Problematic alcohol drinking behaviour was also significantly associated with onset of severe cognitive impairment (SCI) (K-MMSE score ≤17) among those with relatively low-normal K-MMSE score (adjusted OR (aOR)=3.76, 95% CI 1.46 to 9.67). In addition, abstinence, compared with non-problematic drinking, was related to higher risk for developing SCI among men (aOR=1.62, 95% CI 1.09 to 2.39).

Conclusions Our results suggest that those with problematic alcohol drinking behaviour could be at an increased risk of cognitive impairment/decline. While further research will provide stronger evidence, intervention targeting alcohol abuse may play a role in prevention of cognitive impairment.