Alcohol abstinence, excessive intake up risk of dementia
Long-term alcohol abstinence and excessive alcohol consumption appear to increase the risk of dementia, according to a recent study.
“The UK guidelines suggest an alcohol threshold of 12 units/week, but many countries use a much higher threshold to define excessive consumption,” researchers said. [www.iard.org/policy-tables/drinking-guidelines-general-population/]
“The present study encourages the use of a lower threshold of alcohol consumption in such guidelines, applicable over the adult life course, in order to promote cognitive health,” they added.
Over a mean follow-up of 23 years, a total of 397 cases of dementia were recorded. Compared with consumption of 1–14 units/week, abstinence in midlife correlated with a greater risk of dementia (hazard ratio [HR], 1.47; 95 percent CI, 1.15–1.89). [BMJ 2018;362:k2927]
A 7-unit increase in alcohol intake among those drinking >14 units/week correlated with a 17-percent (4–32 percent) increased risk of dementia. In addition, CAGE score >2 (HR, 2.19; 1.29–3.71) and alcohol-related hospital admission (HR, 4.28; 2.72–6.73) correlated with an increase in risk of dementia.
In alcohol consumption trajectories from middle to early old age, a higher risk of dementia was associated with long-term abstinence (HR, 1.74; 1.31–2.30), decrease in consumption (HR, 1.55; 1.08–2.22) and long-term consumption >14 units/week (HR, 1.40; 1.02–1.93) compared with long-term consumption of 1–14 units/week.
Multistate models analysis indicated that cardiometabolic disease over the follow-up partly explained the excess risk of dementia associated with abstinence in midlife, as the HR in abstainers without cardiometabolic disease was 1.33 (0.88–2.02) vs 1.47 (1.15–1.89) in the entire population.
Furthermore, alcohol abstinence is associated with a higher risk of diabetes and cardiovascular disease, which may also heighten the risk of dementia, according to researchers. [Lancet 2009;373:2223-2233; Lancet Neurol 2016;15:455-532; BMJ 2018;361:k934; Lancet Diabetes Endocrinol 2014;2:246-255]
On the other hand, moderate alcohol consumption is believed to benefit cardiovascular health through favourable impacts on lipid profile, inflammation level, endothelial function and insulin sensitivity. [Circulation 2017;136:1434-4; BMJ 2011;342:d636]
“The present findings on alcohol abstinence should therefore not motivate people who do not drink to start drinking given the known detrimental effects of alcohol consumption for all-cause mortality and diseases such as neuropsychiatric disorders, cirrhosis of the liver and cancer,” researchers noted.
This prospective cohort study involved 9,087 participants aged 35–55 years at baseline (1985/88). Outcome measures included alcohol consumption and incident dementia, identified through linkage to hospital, mental health services and mortality registers until 2017.
Measures of alcohol intake were the mean from three assessments between 1985/88 and 1991/93 (midlife), categorized as abstinence, 1–14 units/week and >14 units/week; 17-year trajectories of alcohol consumption based on five assessments between 1985/88 and 2002/04; CAGE questionnaire for alcohol dependence assessed in 1991/93; and hospital admission for alcohol-related chronic diseases between 1991 and 2017.