People here are so quick to poo poo the evidence afforded by anything but double blinded placebo controlled studies, and then turn right around and make claims with no backing at all. And a bunch of people mod them up for it.

This is perhaps the wrong time to voice this complaint - because rejecting the claim made by the dance instructor is the obviously correct response. The study just doesn't say that frequent dancing causes a 76% reduction in the risk of dementia. Even the people who wrote the study would cringe if they saw their work being used to make that claim! This isn't "poo poo", it's "WTF?"!