Alzheimer’s disease has long been viewed as something that originates inside the brain, but an in-depth genomic analysis suggests it may initially triggered by inflammation in distant organs like the skin, lungs or gut – perhaps decades before a person’s memory starts to decline.

This radical reframing of the disease may explain why Alzheimer’s drugs have been disappointing to date, because they act too late in the disease process. Instead, we may need to redirect our efforts towards addressing inflammation in other parts of the body.

“As neuroscientists, we tend to be very brain-centric, but this study really shines a spotlight on the fact that the brain is not disconnected from the rest of the body, and when changes happen in the rest of the body, it affects how the brain functions,” says Donna Wilcock at Indiana University, who wasn’t involved in the research. “Even though Alzheimer’s is a brain disease, we need to think about the whole body when we think about how it begins.”

Image: Alamy

The Alzheimer’s field is being turned on its head as mounting evidence points to the disease beginning outside the brain many years before symptoms start. This may mean we have to totally rethink how we approach preventing and treating the condition.

By Alice Klein