The Oxford University team’s study builds on earlier work that has linked high brain iron levels to neurodegenerative diseases. Frequent drinkers have been shown to be more likely to have early-onset dementia. The scientists sought to find out how moderate amounts of alcohol would affect brain health.
It turned out that as little as four drinks per week can cause brain changes associated with cognitive decline.
Under one serving, scientists understood 10 ml of alcohol. For example, in a large glass of wine there can be about 2-3 servings, and in a can of beer about 1.5, they explain.
More than seven drinks a week provoked an excess of iron in the brain. The researchers noted that the higher these scores were, the lower the cognitive abilities of the participants were determined.
It is not yet clear exactly how alcohol consumption increases iron levels in the brain. According to the most likely hypothesis, alcohol suppresses the production of the hormone hepcidin, which regulates iron homeostasis. As a result, it enhances iron absorption by the intestines and limits its excretion from hepatocytes. In addition, alcohol reduces the level of vitamin B1 (thiamine), and its deficiency, in turn, increases the permeability of the protective blood-brain barrier.
As a preventive measure, scientists advise limiting the amount of alcohol consumed. If further research confirms the hypothesis about the mechanism of iron penetration into the brain, then dietary modification or thiamine supplementation is likely to help reduce the risks.
Meanwhile, according to a recent report from the European Society of Cardiology, levels of alcohol consumption currently considered safe in some countries actually lead to heart failure. They also recommend keeping alcohol consumption to a minimum.