How can we make the brain in a very flexible and healthy state?

You can eat more walnuts. It is said that eating walnuts can make the brain smarter. You should also eat more fruits and vegetables. Don't always eat some fried food or barbecue. That's very unhealthy. It's not good for your brain development and your health. So, you should pay great attention. In addition, drink plenty of water, at least 8 glasses of water a day.