Alzheimer’s disease is an irreversible, progressive brain disorder that slowly destroys memory and thinking skills, and eventually the ability to carry out the simplest tasks. Estimates vary, but experts suggest that more than 5 million Americans may have Alzheimer’s. This disease is currently ranked as the sixth leading cause of death in the United States, and it is the only one that can not be prevented or cured. Alzheimer’s is the most common cause of dementia among older adults.

Changes in the Brain

It seems likely that damage to the brain starts a decade or more before memory and other cognitive problems appear. During this preclinical stage of Alzheimer’s disease, people seem to be symptom-free, but toxic changes are taking place in the brain. Abnormal deposits of proteins form amyloid plaques (abnormal clumps) and tau tangles (tangled bundles of fibers) throughout the brain, and once-healthy neurons stop functioning, lose connections with...