Researchers agree that alcohol use can produce global and regional tissue volume changes in the brain, and that excessive alcohol use is associated with dementia and cognitive decline. A new study has examined the relationship between Alzheimer disease – the most common type of dementia – and alcohol use disorder (AUD), discovering biomarkers that link the two. These results will be shared on Wednesday 26 June 2024 at the 47th annual scientific meeting of the Research Society on Alcohol (RSA) in Minneapolis, Minnesota.

“We knew that AUD is associated with problems with memory and thinking,” said Sarah Hartz, a professor of psychiatry at the Washington University School of Medicine in St. Louis. “We wanted to extend that knowledge, to study associations among longitudinal alcohol use, cognition, and measures of Alzheimer disease neuropathology.”

Hartz and her colleagues accessed data from St. Louis site of the Collaborative Study on the Genetics of Alcoholism (COGA), which is a study founded in 1989 and funded by the National Institute on Alcohol Abuse and Alcoholism in order to identify genes that increase or decrease the risk of AUD, the progression of AUD, and factors related to prevention, treatment, and remission/recovery.

“We measured cognitive decline and blood biomarkers for Alzheimer disease in older adult COGA participants,” said Hartz. “Amyloid and tau are proteins that build up in the brain in Alzheimer’s disease. As these proteins build up in the brain, our body tries to clear them away. As a result, they can end up in spinal fluid – the special liquid which surrounds the brain and spinal cord and protects them – and in our blood, which interacts with the spinal fluid.” New blood tests, she added, have recently been approved that can detect amyloid and tau in the blood and are correlated with the amount of amyloid and tau buildup in the brain.

“Our preliminary analyses show strong relationships between alcohol use disorder, cognitive decline in older adults, and high rates of these Alzheimer disease biomarkers,” said Hartz. “To our knowledge, this represents the first study to integrate Alzheimer disease biomarkers with comprehensive, longitudinal ‎assessments of ‎alcohol use.”

Hartz added that concern exists that even moderate drinking may be bad for our brains, but she said this needs further study. “We all make many lifestyle choices, and use of alcohol may be a choice that is bad for our health and our brains.”