Brain changes appear seven years before Alzheimer's plaques, study finds

September 2, 2026 at 05:00 AM2 min

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A University of Oslo-led study published in Nature Neuroscience found structural brain changes detectable on MRI at least seven years before amyloid plaques appear on PET scans. The researchers followed healthy older adults with regular scans for nearly 20 years, identifying the earliest brain signal linked to Alzheimer's disease to date. The findings suggest current amyloid-PET imaging may miss the earliest disease-related processes.

Key Facts

The study was led by scientists at the University of Oslo's Department of Psychology and published in Nature Neuroscience.
Researchers identified structural brain changes at least seven years before amyloid plaques became visible on PET scans.
The findings are based on MRI scans of healthy individuals followed for nearly 20 years.
James Michael Roe, formerly a postdoctoral researcher at the Center for Lifespan Changes in Brain and Cognition, was the study's main researcher.
Anders Martin Fjell, professor and head of LCBC, called the discovery of structural changes before plaque buildup the most groundbreaking aspect of the study.

Early Structural Changes

The researchers found that structural changes in the brain occur many years before high levels of plaque are seen on PET scans, the current gold standard for identifying early Alzheimer's disease. James Michael Roe, the study's main researcher, stated that the team identified the earliest signal detected on brain scans to date. The study suggests that amyloid-PET imaging may not be sensitive enough to capture some of the earliest brain changes associated with the disease, including processes related to amyloid plaque buildup. Anders Martin Fjell, professor and head of LCBC, emphasized that the participants were cognitively well-functioning older individuals.

Longitudinal Imaging Approach

The researchers followed healthy individuals who underwent regular MRI brain scans for nearly 20 years. The long span of imaging data allowed the team to determine when plaques first became detectable and which participants eventually developed them. The team then compared changes in brain structure among people who later showed plaques with changes seen in people who did not. Fjell noted that Alzheimer's disease remains extremely difficult to treat because it is closely connected with aging and probably influenced by several different biological factors.