The cause of Alzheimer's disease is not clear, and it is likely there are several causes of this condition. Alzheimer's disease causes changes or deterioration in certain areas of the brain that control thinking, communication, and behavior. Some of the deterioration may be related to a loss of chemical messengers in the brain (neurotransmitters)-acetylcholine, in particular-that allow nerve cells in the brain to communicate properly.

It is not clear why these changes in the brain occur, but they are a major focus of Alzheimer's research. Although most people who have Alzheimer's disease do not have a family history of the condition, you are at increased risk for the condition if a member of your family has it.

Some theories have suggested that metals, such as zinc or aluminum, play a role in Alzheimer's disease. But research has not found much evidence to support these theories. Experts agree that there is no reason to leave zinc out of your diet or to avoid items that contain aluminum, such as cooking utensils or soda pop cans.