An unhealthy lifestyle is associated with reduced levels of gamma-aminobutyric acid (GABA) in the brain — a substance that helps maintain the balance of neural activity. This conclusion was reached by researchers from the Thompson Institute at the University of the Sunshine Coast. The study results were published in Cerebral Cortex.

The study involved 79 older adults with preserved cognitive function. Using MRI and MR spectroscopy, researchers measured the levels of brain chemicals and compared them with individual dementia risk scores. These scores were calculated based on lifestyle factors, including physical activity, sleep quality, diet, and social engagement.

The researchers found that participants with an elevated but potentially modifiable risk of dementia had lower GABA levels in the sensory and motor areas of the brain. GABA serves as the brain’s “braking system,” helping regulate excessive neural activity.

In addition, in the prefrontal cortex — responsible for decision-making and complex thinking — participants with higher risk showed reduced levels of total N-acetylaspartate (tNAA) and total choline (tCho), both of which are critical for neural tissue health and communication between brain cells.

According to the study’s lead author, Dr. Jacob Levenstein, the reduction of these neurochemical markers in people without significant cognitive impairments may indicate the onset of changes long before symptoms appear. This opens up opportunities for early diagnosis and dementia prevention.