According to the Centers for Disease Control and Prevention (CDC), alcohol use can increase the risk of cancer, and excessive consumption has been linked to high blood pressure, cardiovascular disease, and stroke, reports Medical News Today.

One area of active research is the effects of alcohol on the brain. A recent study published in the journal Neurology, examined the impact of alcohol consumption on various brain processes associated with dementia and neurodegenerative changes.

The study shows that moderate, heavy and discontinued heavy alcohol consumption are associated with hyaline arteriolosclerosis, a condition in which the walls of small blood vessels in the brain thicken and narrow. This is common in the elderly and individuals with certain health problems.

Former heavy drinkers also show a lower brain mass ratio and poorer cognitive abilities compared to people who have never used alcohol. While further research is needed, the results highlight the potentially harmful effects of alcohol on the brain.

How alcohol affects the brain

The study was population-based and based on autopsies performed in São Paulo, Brazil, covering 1,781 participants. The brain samples were taken from the biobank at the Sao Paulo Autopsy Service and did not include cases of death from trauma.

The mean age of the participants was about 75 years, and the sample was ethnically diverse. All were over 50 years of age and had a close relative who had maintained regular contact with them in the last 6 months of their lives.

Individuals with acute brain injury or no evidence of alcohol use were excluded. Through interviews with relatives of the deceased, the researchers gathered information about medical history, alcohol use, and the presence of dementia.

Participants were divided into the following groups:

Never used alcohol;

Moderate drinkers - up to 7 doses per week;

Heavy drinkers - 8 or more doses per week;

Former heavy consumers - stopped alcohol up to 3 months before death.

One dose of alcohol was taken for 14 grams.

Heavy drinkers had a 133% higher risk of brain damage

After analyzing the results, the researchers found that moderate, heavy and former heavy alcohol use were associated with an increased risk of hyaline arteriolosclerosis. Heavy drinkers had a 133% higher risk compared to people who never drank.

Heavy and former heavy drinkers are also at increased risk of neurofibrillary tangle accumulation, a hallmark of Alzheimer's disease. Former heavy drinkers also show lower brain weights as well as poorer cognitive performance.

Importantly, no direct link between alcohol consumption and cognitive function has been established. Instead, the researchers found that hyaline arteriolosclerosis mediated - that is, it mediated - the relationship between alcohol use and impaired cognitive ability.

Opinion of specialists

Dr. Harris Kamal, a neurologist at Memorial Hermann, told Medical News Today:

"The effect of alcohol on the human brain depends on a multitude of factors - age, duration of use, general health, diet and more. This study shows that even moderate to heavy alcohol use, or even previous heavy use, is associated with progressive thickening of the walls of brain arteries and a buildup of tau-type proteins that can lead to cognitive impairment and dementia."

Study limitations

Among the main limitations is the fact that some of the information (including on drinking habits) was collected from relatives, creating a risk of inaccuracy. Data on duration of use before death were also lacking.

The study focused on people from one country - Brazil - and therefore the results are not necessarily applicable to other populations.

The authors also note the so-called "survival effect" - the fact that heavy users die earlier, which may explain why lower rates of stroke, hypertension and brain lesions were observed in the univariate analysis.

Reverse causality is also possible - that is, some people may have stopped drinking precisely because of cognitive problems.

The study also did not look at nutritional deficiencies, including of vitamins, which can also impair brain function. Future studies should take this into account.

According to Dr. Alberto Justo of the University of São Paulo's School of Medicine:

"Future research should take the form of cohort studies that track the direct causal relationship between alcohol consumption and changes in the brain over time."

Dr Tony Thrasher, who was also not involved in the study, adds:

"Despite the limited accuracy of some of the data, the numbers are impressive. Previous research has already shown that heavy drinkers live significantly shorter lives. This study gives hope to medical professionals seeking evidence for motivational interviewing."

Heavy drinking leads to vascular changes in the brain

The evidence so far clearly shows the potentially serious risks that alcohol poses to brain health. Dr Justo stresses:

"Our study found that even moderate alcohol consumption can lead to vascular changes in the brain, including hyaline arteriolosclerosis. In former heavy drinkers, we observed reduced brain mass and impaired cognitive abilities. This highlights the need for greater awareness of the risks of alcohol even in moderate use."

Dr Kamal adds:

"Clinical implications of these results may include accelerated degeneration of subcortical structures in the brain leading to cognitive problems. Over time, this can manifest through slowed thinking, memory problems and impairments in higher brain functions - symptoms characteristic of vascular dementia." | БГНЕС