At this time, there is no known way to prevent Alzheimer's disease.
Research has been done to link physical activity and the risk of Alzheimer's disease and other dementias. Adults who are physically active may be less likely to get Alzheimer's disease or dementia than adults who are not physically active.5 Moderate activity is safe for most people, but it's always a good idea to talk to your doctor before starting an exercise program.
There is also good evidence that older adults who stay mentally active may be at lower risk for developing Alzheimer's disease.6, 7 Regularly reading newspapers, books, and magazines, playing cards and other games, working crossword puzzles, going to museums, and doing other social activities, and even actively watching television or listening to the radio may help you avoid symptoms of Alzheimer's disease. Although this "use it or lose it" approach has not been proved, no harm can come from regularly putting your brain to work.
Research has also shown that people who eat more fruits and vegetables, high-fiber foods, fish, and omega-3 rich oils (sometimes known as the Mediterranean diet) and who eat less red meat and dairy may have some protection against dementia. But the reason for this is still being studied.8, 9
As we learn more about the causes of Alzheimer's disease, we also may learn more about how to prevent the disease. Drugs now in development to prevent the formation of neurofibrillary "tangles" or amyloid plaques that damage the nerve cells in the brain may someday be used in people who are at risk for Alzheimer's.
Research into a vaccine for Alzheimer's disease is ongoing.