Two glasses of wine a week are enough to cause brain changes

A scientific study published this Thursday (14) showed that moderate consumption of alcohol – about 2 glasses of wine a week – is enough to cause iron accumulation in the brain. This condition is associated with cognitive decline. Until now, it was believed that only abusive consumption of alcoholic beverages could have this effect.

In the study, which was developed by the University of Oxford in the United Kingdom, 21,000 participants answered a questionnaire about their drinking habits, had an MRI to measure the amount of iron in the brain and performed cognitive tests (puzzles, for example). ).

Research has shown that drinking seven units of alcohol weekly – the equivalent of two 8-ounce glasses of wine – is associated with increased iron in a brain region called the basal ganglia.

​Published in the scientific journal Plos Medicine, the study was the largest to investigate the relationship between moderate alcohol consumption and iron accumulation.

According to José Gallucci Neto, physician at the Institute of Psychiatry at Hospital das Clínicas at USP (University of São Paulo), this brain region is responsible for several activities, but the main ones are motor and cognitive functions.

This phenomenon is observed in neurodegenerative conditions, such as Parkinson’s and Alzheimer’s diseases, but it is also closely linked to dependence and alcohol abuse. According to Anya Topiwala, a psychiatrist who led the study, it is already known that drinking for a long time can cause dementia and brain damage.

However, until now it was not known that moderate alcohol consumption also has this effect. What the study shows is that patients who drink moderately not only have greater iron accumulation, but also have greater difficulty in cognitive tests.​

According to Gallucci, cognition is “a set of superior functions that mainly involve memory, attention and performance”. In practice, cognitive decline means greater difficulty in performing simple tasks such as working and learning new things.

For Jerusa Smid, a neurologist and coordinator of the department of cognitive neurology and aging at the Brazilian Academy of Neurology, the main novelty in this article is that it suggests a possible explanation for the cognitive disorders associated with alcohol that are still not well understood.

The study also showed a relationship between alcohol consumption and the accumulation of iron in the liver, but the effect was only seen in participants who consumed at least 11 units of alcohol per week – the equivalent of four and a half cans of beer.

The liver is the main organ affected by alcohol consumption. According to data from the WHO (World Health Organization), 48% of deaths caused by drinking are due to liver cirrhosis, a condition in which the organ ceases to be functional due to the constant occurrence of lesions.

For Gallucci, it is important to emphasize that the damage caused by alcohol is systemic. Although the main effects are observed in specific organs, the substance is toxic to the entire body and can affect, in addition to the body, judgment and emotions.

According to Topiwala, the psychiatrist who led the study, more work needs to be done to understand whether the accumulation is reversible and how it impacts cognition, but, according to her, this is further evidence that “even moderate alcohol consumption is bad for the brain”.

Public health

According to data from PAHO (Pan American Health Organization), alcohol consumption is responsible for 380,000 deaths a year in the Americas – about 5% of all deaths from all causes.

Although most of these deaths are due to liver cirrhosis, the drink also causes diseases such as cancer, hypertension and tuberculosis. Deaths are also related to the occurrence of injuries such as car accidents and homicides.

For Smid, public policies to combat alcohol are not good. “Alcohol is a legal drug that must be fought, like cigarettes”. According to her, precisely because it is legal, policies should be stricter.

According to data from Vigitel 2021 (Surveillance of risk factors and protection for chronic diseases by telephone survey), a survey carried out by the Ministry of Health in Brazilian capitals, 18.3% of adults interviewed reported abusive consumption of alcoholic beverages. The frequency is higher in men (25%), young people (25.5%) and people with higher education (22.5%).

During the pandemic, the use of substances of abuse increased, which prompted the WHO to recommend that governments regulate the sale of beverages. Also according to PAHO, 42% of Brazilian adults interviewed reported high alcohol consumption during the quarantine period.