There's been a long standing idea that dementia and Alzheimer can be prevented by mental exercise. It intuitively seems like a good hypothesis, but as this an o

There's been a long standing idea that dementia and Alzheimer can be prevented by mental exercise. It intuitively seems like a good hypothesis, but as this an other studies in the comments show, it's not true. It is difficult to really test for this though, because you can't control for people's amount of mental exertion, gaming, learning and puzzle solving over their entire lives, so we substitute things like "knows more than one language fluently," something we can objectively measure and see if there's a correlation. This particular study used a group of people that took the same intelligence test when they were young. There's been some research that shows some older people's brains have trouble metabolizing glucose and other sugars, and that diets that push ketosis in older people (higher fats, coconut oil, less cereal/crabs) can help some people: https://www.youtube.com/watch?v=yooNuOKsa1Q https://www.youtube.com/watch?v=yooNuOKsa1Q