As of now, there is no clear evidence of the exact steps you can take to prevent Alzheimer's. However, there are healthy lifestyle choices you can make to help reduce your risk and improve your overall health. That is not to say that enacting these changes/decisions will 100% prevent your chances of developing Alzheimer's. But practicing these healthy lifestyle choices will help improve your brain health. Several of these actions include:
Avoid smoking
Limiting alcohol consumption
Eating a healthy balanced diet (rich in fruits, vegetables, and lean protein)
Engaging in physical exercise that you enjoy
Maintaining a healthy weight
Avoiding head injuries
Taking care of your mental health
Controlling cardiovascular risk factors
Staying mentally active