Alcohol Consumption and Dementia

“Even drinking a moderate amount of alcohol can cause brain damage over a prolonged period of time, scientists have said. In a study of more than 500 adults over 30 years, researchers found people who drank between 14 and 21 units per week were three times more likely to suffer from hippocampal atrophy—damage to the area of the brain involved in memory and spatial navigation.

“The effect of heavy drinking on brain function has long been known. But what impact drinking within government guidelines has on a person’s brain health is not well understood. In the latest study published in the BMJ, researchers from the University of Oxford and University College London looked at the impact of moderate alcohol consumption on the brain…” (Alcohol and Brain Damage: Moderate Drinking Linked to Cognitive Decline, 07 June 2017). 

from Research: moderate alcohol consumption as risk factor for adverse brain outcomes and cognitive decline: longitudinal cohort study (Published 06 June 2017):

“…What is already known on this topic:

• Heavy drinking is associated with Korsakoff’s syndrome, dementia, and widespread brain atrophy
• While smaller amounts of alcohol have been linked to protection against cognitive impairment, few studies have examined the effects of moderate alcohol on the brain
• Previous studies have methodological limitations especially regarding the lack of prospective alcohol data, have been conflicting, and have failed to provide a convincing neural correlate

“What this study adds:

• Compared with abstinence, moderate alcohol intake is associated with increased risk of adverse brain outcomes and steeper cognitive decline in lexical fluency
• The hippocampus is particularly vulnerable, which has not been previously linked negatively with moderate alcohol use
• No protective effect was found for small amounts of alcohol over abstinence, and previous reports claiming a protective effect of light drinking might have been subject to confounding by associations between increased alcohol and higher social class or IQ

Abstract:

“Objectives: To investigate whether moderate alcohol consumption has a favourable or adverse association or no association with brain structure and function.

“Design: Observational cohort study with weekly alcohol intake and cognitive performance measured repeatedly over 30 years (1985-2015). Multimodal magnetic resonance imaging (MRI) was performed at study endpoint (2012-15).

“Setting: Community dwelling adults enrolled in the Whitehall II cohort based in the UK (the Whitehall II imaging sub-study).

“Participants: 550 men and women with mean age 43.0 (SD 5.4) at study baseline, none were ‘alcohol dependent’ according to the CAGE screening questionnaire, and all safe to undergo MRI of the brain at follow-up. Twenty three were excluded because of incomplete or poor quality imaging data or gross structural abnormality (such as a brain cyst) or incomplete alcohol use, sociodemographic, health, or cognitive data.

“Main outcome measures: Structural brain measures included hippocampal atrophy, grey matter density, and white matter microstructure. Functional measures included cognitive decline over the study and cross sectional cognitive performance at the time of scanning.

“Results: Higher alcohol consumption over the 30 year follow-up was associated with increased odds of hippocampal atrophy in a dose dependent fashion. While those consuming over 30 units a week were at the highest risk compared with abstainers (odds ratio 5.8, 95% confidence interval 1.8 to 18.6; P≤0.001), even those drinking moderately (14-21 units/week) had three times the odds of right sided hippocampal atrophy (3.4, 1.4 to 8.1; P=0.007). There was no protective effect of light drinking (1-<7 units/week) over abstinence. Higher alcohol use was also associated with differences in corpus callosum microstructure and faster decline in lexical fluency. No association was found with cross sectional cognitive performance or longitudinal changes in semantic fluency or word recall.

“Conclusions: Alcohol consumption, even at moderate levels, is associated with adverse brain outcomes including hippocampal atrophy. These results support the recent reduction in alcohol guidance in the UK and question the current limits recommended in the US…”

Research: Moderate alcohol consumption as risk factor for adverse brain outcomes and cognitive decline: longitudinal cohort study (Published 06 June 2017). Read the Entire Study Here: https://doi.org/10.1136/bmj.j2353