Brain Changes May Precede Alzheimer’s Plaques by Years, Study Finds

Alzheimer’s May Mark the Brain Years Before Plaques Show Up

Tracking healthy adults with MRI for nearly two decades, researchers found structural brain changes at least seven years before amyloid plaques became visible on scans.

By iPharmag Editorial Desk · Sep 6, 2026 · 1 min read

Conceptual illustration of a brain with early cortical changes on a timeline

Conceptual illustration. Cortical thinning may appear years before amyloid plaques are visible on scans.

Alzheimer’s disease is often defined by amyloid plaques — sticky protein clumps in the brain. But new research suggests the brain may start changing years before those plaques are even detectable.

Scientists at the University of Oslo, led by James Michael Roe, used MRI brain scans collected over nearly 20 years in cognitively healthy older adults. Comparing people who eventually developed plaques with those who didn’t, they found structural changes in the brain’s cortex — cortical thinning — at least seven years before plaques showed up on PET scans. The findings appeared in Nature Neuroscience.

Two possibilities

The researchers offer two explanations, and can’t yet say which is right: either harmful processes tied to plaques are already active before the plaques become visible, or separate, non-amyloid processes drive the early changes. “Structural changes in the brain occur many years before high levels of plaque are seen on PET scans,” Roe noted.

Why it matters — and the caveat

If the earliest damage precedes amyloid, it could reshape both early detection (spotting risk sooner via imaging) and treatment (whether targeting amyloid alone is enough, or whether other processes need addressing). But the mechanism remains unclear, and it’s an observational finding — more research is needed before it changes how Alzheimer’s is diagnosed or treated.

Frequently asked questions

Does this change how Alzheimer’s is diagnosed?

Not yet. It is an observational finding that structural brain changes may precede visible plaques by years. The mechanism is unclear, and more research is needed before it affects diagnosis or treatment.

Why does timing before plaques matter?

If the earliest brain damage happens before amyloid plaques form, it raises questions about detecting risk sooner and whether targeting amyloid alone is enough, or whether other processes also need to be addressed.

This article is for general information only and is not medical advice. Consult a qualified healthcare professional for any medical decisions.