Image Courtesy: Shutterstock

Poor sleep has long been linked to an increased risk of Alzheimer’s disease, but new research suggests that genetics may determine how severely sleep deprivation affects the brain. Scientists have found that variations in a gene involved in the brain’s waste-removal system can influence whether poor sleep accelerates changes associated with Alzheimer’s years before symptoms appear.

Researchers at Edith Cowan University’s Centre for Precision Health focused on the aquaporin-4 (AQP4) gene, which regulates the movement of fluid through the brain and supports the glymphatic system, the process responsible for clearing waste products during sleep. Their findings suggest that the impact of sleep habits on brain health differs depending on which version of the gene a person carries.

The team analyzed 13 common AQP4 gene variants alongside participants’ self-reported sleep patterns, brain scans, and cognitive test results. They found that individuals with certain genetic variants experienced faster grey matter loss when they reported shorter sleep durations. In other cases, taking longer to fall asleep was linked to lower brain volume and structural changes associated with cognitive decline.

Grey matter contains many of the brain cells responsible for memory, decision-making, movement, and other essential functions. Loss of grey matter is considered an early indicator of structural brain changes that may contribute to Alzheimer’s disease.

Lead researcher Dr. Ayeisha Milligan Armstrong said the findings highlight the interaction between genetics and lifestyle. She explained that the same genetic variant could appear either protective or harmful depending on an individual’s sleep habits, making sleep one of the few risk factors people can actively improve.

The researchers emphasized that the findings do not justify routine genetic testing. Instead, they believe the study supports a more personalized approach to Alzheimer’s prevention, where lifestyle interventions such as improving sleep quality could be tailored to individuals based on their genetic risk.

Published in Alzheimer’s & Dementia, the study calls for larger clinical trials to confirm the findings and determine whether improving sleep can reduce inherited vulnerability to Alzheimer’s. If validated, the research could help explain why some people experience faster brain decline than others despite having similar overall risk profiles.