Even moderate alcohol consumption can damage the brain and impair its performance. In what they claim to be the largest study on the subject to date, scientists from the University of Oxford have found a link between alcohol consumption and iron deposits in certain areas of the brain – even at alcohol levels that professional societies still consider acceptable. Iron deposits were accompanied by a decrease in cognitive abilities, the researchers write in the journal Plos Medicine.
It has long been proven that excessive alcohol consumption is harmful to the human body. But does alcohol have an impact on health, even in small doses? Some studies in the past have concluded that alcohol – consumed in small amounts as a stimulant – can have positive effects. According to other studies, even moderate amounts can harm brain health and lead to nerve cell death. However, the exact mechanisms underlying this are still largely unexplored.
A possibility of neurodegeneration due to moderate drinking behavior could be iron deposits in the brain. The neurological consequences of increased iron content in the brain have long been known in patients with hereditary iron overload disorders. In recent studies, they are associated with various neurodegenerative diseases such as Alzheimer’s disease or Parkinson’s disease. Interestingly, the clinical profile of alcohol-related dementia overlaps with these disorders. Additionally, recent observations indicate that alcohol addiction can also lead to iron accumulation. It is not yet clear whether such deposits occur in moderate drinkers.
The increase in iron levels was accompanied by a decrease in cognitive performance in study participants.
To answer this question, researchers led by Anya Topiwala surveyed a total of 20,965 women and men between the ages of 40 and 69 about their alcohol consumption. Iron levels in the brain and liver were measured using magnetic resonance imaging (MRI). Participants were also given a series of cognitive tests to measure skills such as attention, reaction speed, motor skills, memory and logic.
Even a weekly alcohol consumption of more than 56 grams, which remains well below UK “low risk” guidelines, was associated with elevated levels of iron in six of the seven brain regions studied, the researchers explain. The increase in iron levels was accompanied by a decrease in cognitive performance in study participants. In tests, they showed slower reaction speed and reduced attention and were less able to solve logic puzzles.
The results indicate that even moderate alcohol consumption can upset the body’s iron balance. A weakness of their study is that participants had to self-assess their alcohol consumption, the team writes. Moreover, the iron content was only measured indirectly. It is also unclear how the results of the study can be transferred to other ethnically diverse population groups.
In Germany, the German head office for addiction problems recommends that women drink no more than 12 grams of alcohol per day, two days should be completely alcohol-free. This corresponds to a maximum of 60 grams of alcohol per week. For men, the value is 24 grams per day, or 120 grams per week. The recommendations of the German Nutrition Society are similar. 60 grams corresponds to approximately five small glasses of wine or five small beers. If the findings of the UK study are confirmed by further investigation, these amounts can no longer be considered low risk.