Cognitive dysfunction eventually leads to a loss of independence that becomes a burden on families and society, as the individuals require more intense care and often institutionalisation. In the later stages, the cognitive impairment associated with dementia will create total dependency and thus, dementia is one the major causes of disability and disability burden overall among older adults globally (WHO 2023). Since so far there is no cure, identifying those factors, which are associated with preserving the cognitive function could lead to substantial improvements in the quality of life in older adults. Systematic reviews of health behaviours, which maintain healthy cognitive function suggest that the intake of fish and vegetables, moderate physical activity and moderate consumption of alcoholic beverages might be protective against cognitive decline and dementia. Studies have indicated that alcohol acts directly and indirectly on the brain. Previous reviews have indicated that light to moderate consumption of alcoholic beverages in middle to late adulthood was associated with a decreased risk of cognitive impairment and dementia. Conversely, heavy alcohol consumption was related to changes in cognitive impairments, and an increased risk of all types of dementia.
The current large retrospective cohort study of four million individuals, who were followed for six years, adds to the evidence that a decreased risk of dementia was associated with maintaining mild to moderate consumption of alcoholic beverages. The researchers found that sustained mild drinkers had a 21% decreased risk of all-cause dementia, and sustained moderate drinkers had a 17% decreased risk of all-cause dementia compared to non-drinkers, whereas sustained heavy drinkers had an 8% increased risk.
This study additionally showed that heavy drinkers who reduced their intake to a moderate level, and non-drinkers, who initiated drinking to a mild level, showed a decreased risk of all-cause dementia and Alzheimer Disease (AD). In contrast, those individuals who increased their consumption of alcoholic beverages from a mild or a moderate level to a heavy level had an increased risk of all-cause dementia and AD. Collectively, these data suggested that the threshold of alcohol consumption for dementia risk reduction is low.
The authors concluded that maintaining mild to moderate drinking of up to 30 g/day might be beneficial for the brain and is associated with a decreased risk of dementia, whereas maintaining heavy drinking is associated with an increased risk of dementia.
WHO 2023: https://www.who.int/news-room/fact-sheets/detail/dementia