Tobacco and alcohol increase the risk of dementia

Smoking and alcohol consumption make the brain shrink
Tobacco and alcohol consumption are associated with numerous health risks, although very few people think of permanent impairments of cognitive performance and an increased risk of dementia. A recent study by the research team headed by Dr. med. Kevin King of the Keck School of Medicine at the University of Southern California, Los Angeles, however, shows that alcohol and tobacco also cause lasting changes in the brain, which in turn increase the risk of dementia and Alzheimer's.

Smoking and alcohol use, according to US researchers, are cardiovascular risk factors that have a significant impact on the brain. The volume in certain brain regions decreases significantly in alcohol and tobacco consumption, with the affected brain regions are strongly associated with a cognitive decline, as seen in dementia and Alzheimer's, King and colleagues report in the journal "Radiology".

The combination of alcohol and tobacco significantly reduces the brain volume and increases the risk of dementia. (Picture: Syda Productions / fotolia.com)

Measurement of brain volume
Overall, the researchers evaluated data from 700 men and 929 women, average age 50, from the Dallas Heart Study. With the help of magnetic resonance imaging (MRI), the volume of the individual brain regions was determined at the start of the study, and a new measurement was made after seven years. In addition, the cognitive performance of the participants was tested by means of a special test (Montreal Cognitive Assessment, MoCA). Accompanying the study, the researchers recorded cardiovascular risk factors such as tobacco and alcohol consumption by filling out questionnaires.

Volume decreased in different brain regions
The measurements of brain volume revealed, according to King and colleagues, that both alcohol consumption and smoking were associated with decreased hippocampal volume. In addition, the two cardiovascular risk factors correlated with a lower overall volume in the posterior cingulate and precuneus. Also in diabetes, the total brain volume is reduced. The combination of tobacco use and obesity leads to a lower volume in the back cingulate, the combination of alcohol and obesity to a smaller volume of the precuneus region. However, other cardiovascular risk factors, such as high cholesterol or triglyceride levels, have been associated with greater volume of the posterior cingulate and precuneus. The reduced volume of the hippocampus mainly influenced the results in the test of cognitive performance; of the posterior cingulate and precuneus, the scientists report.

Indicators of an increased risk of dementia
Decreased volumes in certain brain regions, such as those caused by smoking and alcohol consumption, are early indicators of increased dementia risk and cognitive deficits, according to Kevin King and colleagues. Since no cure for dementia and Alzheimer's is possible, prevention plays a special role. Targeted education of the population about the effect of individual risk factors on the brain volume could possibly contribute to a sharper awareness of the impending impairment. (Fp)