New research suggests that drinking seven or more units of alcohol each week can lead to the accumulation of iron levels in the brain, which is linked to Alzheimer’s and Parkinson’s diseases.
A study of almost 21,000 people found their average weekly alcohol intake was 18 units a week – around 7.5 cans or beer or six large glasses of wine. Researchers found that drinking more than seven units a week was linked to higher levels of iron in parts of the brain responsible for motor movements, emotion, cognition, eye movement and more.
Anya Topiwala, from the University of Oxford, carried out the research with colleagues, saying: “In the largest study to date, we found drinking greater than 7 units of alcohol weekly associated with iron accumulation in the brain. Higher brain iron in turn linked to poorer cognitive performance. Iron accumulation could underlie alcohol-related cognitive decline.”
The study participants reported how much alcohol they drank each week, with MRI scans used to assess their brains. MRI scans were also used on around 7,000 participants to examine iron levels. All those taking part undertook a series of challenges to test their cognitive and motor function.
The research team said that, given how commonplace moderate drinking is, efforts to reduce consumption would be beneficial.
The study has been published in PLOS Medicine.