Those who consume eight or more alcoholic drinks a week have an increased risk of developing brain damage called vitreous arteriosclerosis. That’s according to a study published online in the American Academy of Neurology medical journal Neurology.

Vitreous arteriosclerosis is a condition that causes narrowing of small blood vessels, which become thick and stiff. This impedes blood flow, which can damage the brain over time. It appears as areas of damaged tissue in the brain.

Researchers looked at how alcohol affects the brain as people age and found that heavy drinking is damaging to the brain and can lead to memory and thinking problems.

The research studied brain tissue from 1,781 people who had an average age of 75 at death. All had undergone a brain autopsy. The researchers’ goal was to look for signs of brain damage. They also measured the brain weight and height of each participant. Family members answered questions about the participants’ alcohol consumption.

They then categorized the data into four groups, for people who never drank, moderate drinkers who drank seven or fewer drinks a week, heavy drinkers who consumed eight or more drinks a week, and those who had been heavy drinkers in the past. The researchers defined a drink as containing 14 grams of alcohol, which is roughly equivalent to 350 ml of beer, 150 ml of wine or 45 ml of distilled spirits.

After adjusting for factors that could affect brain health, such as age at death, smoking and physical activity, it was found that heavy drinkers were 133% more likely to have vascular brain damage compared with those who never drank, former drinkers were 89% more likely and moderate drinkers were 60% more likely.

It was also found that heavy drinkers died an average of 13 years earlier than those who never drank. In addition, heavy drinkers and former drinkers were more likely to develop neurofibrillary tangles, a biomarker associated with Alzheimer’s disease, with 41% and 31% more chance, respectively.

Heavy past alcohol consumption was associated with a lower brain mass ratio, that is, a lower percentage of brain mass compared with body mass, and worse cognitive abilities. No association was found between moderate or heavy drinking and brain mass ratio or cognitive abilities.

The researchers note that the study does not prove that heavy drinking causes brain damage, but it does show an association. One limitation of the study was that it did not examine participants before death and did not have information on the duration of alcohol consumption and their cognitive abilities.