This is an extremely well-researched, clearly written, and persuasive book about how you can keep your brain sharp at any age. He's a neurosurgeon and chief medical correspondent at CNN and definitely knows what he is talking about. I learned that dementia and Alzheimer's both start 10-20 years before any symptoms appear. But he is not a fear-monger. Even if you already have Alzheimer's there are things that can be done to slow it down and improve quality of life. And, it can be prevented. I thought he'd talk about doing things like crossword puzzles--but actually what is far more important is getting regular exercise--most important. Eating well--with a focus on eating fruits, vegetables and other good things rather than avoiding bad things. Getting good sleep, having quality connections to other people, learning and discovering new things, and having purpose and meaning in your life. At the end of the book are tons of resources for caretakers and people with brain disease. This is one of those books that I think everyone would benefit from reading.