You always need to keep learning new things in order to lower the risk of Alzheimer's disease. The more you learn the stronger your brain will become. A fun way to go about it is to learn creative things like learning an instrument, painting, pottery, etc. The action of learning and experiencing new things will stimulate the process. You can also learn a new language, try sculpting, etc. The more complex the activity, the greater benefit will it bring to your brain.