It looks like baseline dementia risk is about ~8%[1], so a 4% percent increase in the absolute risk of getting dementia which I would consider to be pretty seve

It looks like baseline dementia risk is about ~8%[1], so a 4% percent increase in the absolute risk of getting dementia which I would consider to be pretty severe. [1] https://n.neurology.org/content/95/5/e519 https://n.neurology.org/content/95/5/e519