Scholar Google search == scientific evidence (usually :) ). First link from a query of "exercise dementia": "Exercise Is Associated with Reduced Risk for Incid

Scholar Google search == scientific evidence (usually :) ). First link from a query of "exercise dementia": "Exercise Is Associated with Reduced Risk for Incident Dementia among Persons 65 Years of Age and Older" (http://annals.org/aim/article/719427/exercise-associated-reduced-risk-incident-dementia-among-persons-65-years http://annals.org/aim/article/719427/exercise-associated-red...) Second link: "The effects of exercise training on elderly persons with cognitive impairment and dementia: A meta-analysis" (http://www.sciencedirect.com/science/article/pii/S0003999304003971 http://www.sciencedirect.com/science/article/pii/S0003999304...) (Conclusion: "Exercise training increases fitness, physical function, cognitive function, and positive behavior in people with dementia and related cognitive impairments.") Overall the balance of the articles seem to indicate positive effects for exercise in both preventing dementia and even improving the prospects of people with dementia. This does not mean exercise is a "magic bullet" to completely preventing or curing dementia, but it seems like exercise helps.