Uncovering mechanisms to prevent dementia with quantifiable feedback from wearable devices

[[abstract]]Being diagnosed with dementia can be devastating. A recent Wall Street Journal article1 described dementia in the US as “not just an awful disease, but 90 million baby boomers are entering the prime age with dementia and will swamp Medicare and Medicaid.”To make matters worse, the report said, “if you get sick, there is no cure or even drug treatment.”Prevention continues to be the major solution, and exercise stays at the top among 11 modifiable risk factors determined by the Lancet Commission on dementia.2 Indeed, in a study reported by A. R. Tari et al. in this issue,3 exercise above a threshold of 100 PAI (Personal Activity Intelligence)/week significantly reduced dementia risk. Based on a cohort of 29,826 healthy Norwegians followed for 24 years, increasing PAI score or maintaining a high one, measured 10 years apart, led to a reduction of 25% incidence and 38% mortality of dementia