Alzheimer’s disease is a primary degenerative encephalopathy that occurs in old age and pre-aging, and its prevention, including the following aspects: 1. Dietary balance: The activity of nerve cells requires sufficient protein, calories, lecithin, choline, vitamins, trace elements, etc. On top of this, various necessary nutritional elements can be supplemented. You can eat more vegetables, cereals, beans, appropriate consumption of walnuts, pecans and other dried fruits, usually eat more sea fish and shellfish, limit the intake of red meat, these habits are beneficial to the improvement of memory and the delay of cognitive function decline. 2, diligent brain: often think about moving the brain can help protect the brain’s acuity, promote brain blood circulation, reduce the risk of dementia. The elderly should actively use their brains, such as playing board games, reading, or speaking their thoughts while reading can achieve the purpose of brain activity. 3, maintain good social activities: the elderly should actively enjoy nature; plus various forms of social activities, more communication with people to discuss problems, can also slow down the decline of brain function. 4, moderate exercise: moderate exercise can ensure the fitness of the body, improve immunity, for the elderly, often do some manual will promote brain activity has the effect of preventing dementia. However, exercise should be moderate to avoid falls. 5, maintain a good state of mind: the elderly should pay attention to adjust their mindset, to avoid being too negative, to face life with a cheerful mood. Therefore, elderly people can reduce the risk of dementia through reasonable diet, brain exercise, normal socialization, moderate exercise and keeping a good mentality.