It is a question we naturally ask ourselves when one of our parents develops dementia. This article helps sift through what has been proven to help reduce the risk of developing dementia and what hasn't been proven.
Bottom line -- what is good for your heart is good for your brain!
http://www.washingtonpost.com/national/health-science/my-mom-had-alzheimers-whats-my-risk-of-getting-it-too/2015/08/17/3ba5a668-2fae-11e5-8353-1215475949f4_story.html