Moderate drinking has been associated with a lower risk of developing and dying from heart disease and stroke. But alcohol is known to damage brain cells, leading to the belief that it most likely can’t improve outcomes for dementia.
However, researchers from Denmark set out to challenge this general theory and see if the positive association between alcohol and the reduced risk of cardiovascular disease could be replicated in dementia patients.
The study was part of a broader study: the Danish Alzheimer’s Intervention Study (DAISY), and drew of data from 321 dementia patients and their carers.
DAISY set out to assess the impact of a 12 month program of counselling and support, and tracked progress for three years afterwards, accumulating a considerable amount of data.
This included information on how much alcohol people with early stage dementia or Alzheimer’s drank every day. Around one in 10 (8 per cent) drank no alcohol and at the other end of the scale, around one in 20 (4 per cent) drank more than 3 units daily.
Most of the sample (71 per cent) drank one or fewer units a day; 17 per cent drank 2-3 units.
Analysing the data, the researchers found that drinking two to three units of alcohol every day was linked to a reduced risk of death among people with early stage Alzheimer’s disease – and the difference was significant, with a 77 per cent lowered risk of death compared to those drinking one or fewer daily drinks.
People who drank more or less than two to three units of alcohol saw no change to their risk of death.
These results held true after taking account of influential factors: gender, age, other underlying conditions, whether the individual lived alone or with their primary carer, educational attainment, smoking, quality of life, and the stage of their disease.
The researchers say there could be several explanations for the findings, including that people who drink moderately have a richer social network, which has been linked to improved quality, and possibly length, of life.
Another explanation may lie in the fact that the seemingly protective effect of alcohol may have been caused by reverse causality, whereby those drinking very little alcohol were in the terminal phase of their life, which would have artificially inflated the positive association.
In a bid to correct for this, the researchers re-analysed the data, omitting the first year of monitoring. But this made no difference to the findings.
“The results of our study point towards a potential, positive association of moderate alcohol consumption on mortality in patients with Alzheimer’s disease. However, we cannot solely, on the basis of this study, either encourage or advise against moderate alcohol consumption in [these] patients,” they caution.
They suggest that further research looking at the impact of alcohol on cognitive decline and disease progression in patients with mild Alzheimer’s disease would be particularly informative.