What do you do if a loved one shows signs of Alzheimer's disease?

Forgetfulness is a common sign of aging. Brain cells have died, resulting in memory lapses. But these memory lapses may be early signs of Alzheimer's disease, a condition which progesses over time if left untreated and can result in total memory loss, in which a person no longer recognizes family members or close friends. What do you do if a loved one shows signs of Alzheimers? Are their foods you can eat which may slow down  the disease or even eliminate it completely? How do you develop the patience to handle the changing behavior of one who is suffering from Alzheimer's disease? How will it affect your family's lifestyle?