It is a very well-known fact that heavy drinking is directly linked to chronic disease, from damage to the liver to a higher risk of throat, esophagus, and even breast cancer. What most people don’t know is that moderate drinking—namely, just one cup a day—could also posit some serious health risks.
According to a new study, even moderate drinking may be related to higher iron levels in the brain. Iron accumulation in the brain can be detrimental to memory and thinking skills.
Previous research had already documented that people with alcohol use disorder have structural changes in their brains, compared to healthy people’s brains, such as reduced gray matter and white matter volume.
However, those findings were related to people with a history of alcohol abuse, namely more than four drinks a day for men and more than three drinks a day for women. As per the national dietary guidelines from the U.S. Department of Health and Human Services, drinking no more than two standard drinks for men and one drink for women each day is within the normal drinking range. A standard drink in the U.S. is 12 ounces of beer, 5 ounces of wine, or 1½ ounce of liquor.
In a recent study, researchers examined functional MRI brain scans from 36,678 healthy adults, ages 40 to 69, in the U.K. and compared those findings to their weekly alcohol consumption, adjusting for differences in age, sex, height, social and economic status, and country of residence, among other things.
What the researchers found was that the more alcohol a person drank, the more their gray matter and white matter volume decreased, getting progressively worse the more drinks they had in a week. The researchers also noted that they could tell the difference between brain images of people who never drank alcohol and those who had just one or two drinks a day.
Going from one unit of alcohol to two was linked to changes similar to 2 years of brain aging and mental health deterioration.
Additionally, studies have found that among nearly 21,000 middle-aged and older adults, those who drank as little as a few beers a week showed more iron accumulation in their brains than non-drinkers. Iron buildup in certain brain areas directly correlates with weaker scores on tests of mental abilities like planning, reasoning, and problem-solving.
These findings support the evidence that there may be no “safe” level of drinking when it comes to brain health.
“Even small amounts of alcohol, within current alcohol guidelines, could harm your brain,” said lead researcher Dr. Anya Topiwala of the University of Oxford in the United Kingdom. Even though the brain requires a certain level of iron to function normally, there is a direct link between excess iron accumulation and an aging brain, which could cause a slow deterioration in memory and thinking skills, leading to dementia.
Topiwala also clarified that although the effects of moderate drinking on test performance were small, they appeared to add to the effects of aging. Although people’s mental sharpness is expected to wane with age, higher brain iron seems to worsen that effect.
The studies also have several drawbacks. The subjects analyzed were all middle-aged Europeans, so findings might be different in younger people or those with different genetic makeup. They were also based on how much the patients reported drinking over the past year, which they might not remember correctly or might be different from previous years.
The findings still raise the need for more studies on this matter as well as whether national recommendations for alcohol drinking have to be revised, and whether there is a “safe” level of drinking after all.
