In 1984, around 30% of Americans were diagnosed with dementia by the end of their 80s. Today it’s 10%.

If rates had stayed steady there would be 17 million Americans with dementia today. Instead there are 6 million. This saves us around a trillion dollars in medical bills per year and unknowable suffering.

Every five year cohort measured has had a lower risk than the cohort before them.

We don’t know why.