Everyone knows drinking too much is bad for the body. But a new study from leading U.S. research centers shows that even small amounts can seriously damage the brain.
The researchers linked alcohol use to reduced cerebral blood flow and thinning of the cerebral cortex (the part of the brain responsible for complex thinking). They also suggested that the effects of occasional drinking could build up over time.
The researchers found these signs in men who drank about 60 standard servings per month and in women who drank about 30 standard servings per month. Each standard serving equaled 14 g of pure ethanol. That’s roughly:
- a standard can of beer
- a 150 ml glass of dry wine
- a 50 ml shot of spirits
How the study was done and what it found
The researchers aimed to find correlations between alcohol consumption, age, measures of blood flow, and cortical thickness.
The team recruited 45 healthy adults aged 22 to 70. None of the participants had a history of alcohol-related disorders, and none had been drinking excessively in the past year.
Participants answered questions about their drinking habits over the past year, the past three years, and their lifetime.
On average across their adult lives, the participants drank 21 servings per month. In the sample, monthly intake ranged from 1 to 54 servings.
The team compared the self-reported drinking data with MRI results that measured cortical volume and thickness and with measures of cerebral blood flow. The scans and blood-flow tests were performed only once. The participants were not followed over time.
Cortical thickness was clearly linked to alcohol intake: thickness decreased as alcohol consumption increased. The association between alcohol and cerebral blood flow was even stronger. That pattern suggests alcohol has a major effect on blood flow, which raises the risk of damage to brain tissue.
Cerebral blood flow plays a crucial role in delivering oxygen and nutrients to the brain and in removing waste.
The researchers believe one key consequence of alcohol use is biological wear-and-tear in the form of oxidative stress.
There’s no safe level of alcohol
The study did not demonstrate a direct causal link, partly because it captured a single point in time. The drinking data were self-reported and could be inaccurate. Factors such as diet and physical activity were not accounted for.
Even with those limitations, the results published in the journal Alcohol (via ScienceDirect) merit attention because they align with recent studies that have challenged the idea of any safe level of alcohol.
Photo: Unsplash
