Here’s a NYT article with good information about aging well, including dancing.
https://www.nytimes.com/guides/well/how-to-age-well
And this article is specifically about the effects of contra dancing. ” A new study that compared the neurological effects of country dancing with those of walking and other activities suggests that there may be something unique about learning a social dance.”
https://www.nytimes.com/2017/03/29/well/walk-stretch-or-dance-dancing-may-be-best-for-the-brain.html