An illustration of amyloid plaques on a nerve cell
Sebastian Kaulitzki / Alamy
A blood test that indicates if someone is at high risk of developing Alzheimer’s disease went on sale to the public in the US on 31 July. It could give people an early warning about their deteriorating health, perhaps allowing them to take preventative measures, says the manufacturer, Quest Diagnostics. But some doctors are urging caution, saying the science is still too uncertain and a positive result could cause people great distress for no real benefit.
The test is based …