Alzheimer’s disease begins destroying the brain years before mental deterioration is detected, a new study suggests. This finding means there could be twice the number of people with the neurodegenerative disease in the United States — and worldwide — as currently believed.  Cognitively normal individuals who had elevated levels of a toxic brain protein called amyloid experienced more rapid declines in thinking than those with normal levels. The 445 subjects were followed for as

long as 10 years after their assessment to detect any changes. The median time was 3.1 years, and the subjects’ average age was 74.  The study adds to evidence that Alzheimer’s actually begins years before symptoms appear, said Paul Aisen, M.D., senior author of the study. Aisen directs the University’s of Southern California’s Alzheimer’s Therapeutic Research Institute, located in San Diego. Published in the Journal of the American Medical Association, the study can be found at j.mp/jamyloid. Aisen is the senior author; Michael Donohue, also of ATRI, is first author.  READ MORE