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Treating Alzheimer’s as having many causes may help us beat it

We have focused on the same suspected cause of Alzheimer's for too long. Thinking of it as resulting from multiple overlapping risk factors gives us an opportunity to fight back

Alzheimer's disease. Series of coloured computed tomography (CT) scans of an axial section through the head of a 74-year-old patient with Alzheimer's disease. The front of the brain (brown) is at the top. Alzheimer's is a neurodegenerative disease and a common cause of dementia in the elderly. It causes brain atrophy (decrease in size), shown here by the enlarged ventricle cavities (white, at centre of brain) and the widened pale blue regions. The brain shrinkage caused by Alzheimer's disease leads to memory loss, confusion, personality changes and ultimately death. The cause of Alzheimer's disease is not known and there is no cure.

FOR nearly three decades, we have waited anxiously for a blockbuster drug that could defeat Alzheimer’s disease. We believed we had identified the culprit behind this debilitating condition: . Even as drug after drug homing in on this target failed to make a difference to symptoms, we continued to pour more money into the effort.

Regrettably, it is now becoming clear that this time could have been better spent zooming out from beta-amyloid, to look at the big picture of possible Alzheimer’s causes.

Doing so reveals a far more complicated and insidious illness. It seems to be a condition that doesn’t have a lone underlying trigger, but instead results from multiple overlapping processes and risk factors, which you can read about in detail in our cover story.

By thinking of Alzheimer’s in the same way as we do multifaceted conditions like heart disease, researchers are now combining knowledge from across disciplines to identify, and tackle, the many known risk factors.

“There is a real possibility that we could dismantle Alzheimer’s by a thousand tiny cuts”

This new approach comes not a moment too soon, because 10 million new cases of dementia are diagnosed globally each year. The vast majority of these, between 60 and 70 per cent, are Alzheimer’s disease. As people are living longer than ever, the number of people living with dementia is .

Accepting that Alzheimer’s is more complicated than we thought might seem disheartening. And yet, targeting the many factors implicated in the disease, including the role of infections, diet, sleep habits and inflammation, puts at least some control back in our own hands, because these are things we can all do something about. It means we don’t have to simply wait for pharmaceutical companies to deliver: we can also cut our own chances of getting dementia.

Tunnel vision has held us back for too long. With this new approach, a single blockbuster drug might well be out of the picture, but instead, there is a real possibility that we could dismantle Alzheimer’s by a thousand tiny cuts.

Topics: Alzheimer's disease / Mental health