A whisper in the blood, decades before Alzheimer's speaks

People with Down syndrome face a far higher risk of Alzheimer's, and Olivia Belbin's team at Barcelona's Sant Pau Research Institute may have found the earliest warning sign yet. They tracked a protein called beta-synuclein, which leaks into blood when the junctions between brain cells — the synapses — start to fail. In 131 participants, it was already running 1.83 times higher in people with no symptoms at all, rising in their thirties — about 21 years before the average diagnosis, and seven years ahead of other blood markers. One day, a simple blood draw instead of a spinal tap could open the door to trials at the earliest stage, when treatments stand the best chance. Published in Alzheimer's & Dementia.