There is no certain way to prevent Alzheimer's disease. However, it may be possible to reduce the risk of developing the illness or to delay the onset of the dementia symptoms. Because Alzheimer's disease occurs late in life and there is such a long duration between the onset of symptoms and death, the ability to delay the time when the first problems become evident would be particularly useful. For example, if the average age of symptom onset could be delayed by just five years (from age 75 to age 80), many people would not become severely impaired until age 90. Often other medical problems will intervene and cause death before the point where nursing home admission becomes necessary. If the onset could be delayed by ten years, most people would be more likely to die of other causes before their Alzheimer's disease reached the point where they routinely required the assistance of others. A delay of 20 years would essentially mean that Alzheimer's disease would be a significant health problem only for those individuals who lived beyond age 100.

As with other body parts, the brain is subject to wear and tear and is not immune to the ravages encountered in life. Thus, as people age, it is prudent to do everything reasonable to protect their brains from premature failure. This will allow them to function at their best despite the development of a late-life neurodegenerative illness such as Alzheimer's disease. Thus, while there is no certain formula for preserving brain function throughout the entire life span, there are some things that may be helpful. People should maintain lifestyles that are as physically, mentally and socially active as possible. They should exercise both their brains and bodies on a regular basis. They should maintain a healthy, nutritious diet. People should take vitamin E daily, consulting their doctor for the appropriate dose, avoid excessive alcohol, and review all medications they take (both prescription and non-prescription) with their physician on a regular basis.