I dunno know that Alzheimers is due only to increasing numbers of septagenarians...isn't there a theory that increased exposure to aluminum might be a factor? (since abnormally large deposits of aluminum have been found in the brains of soem Alzheimers patients at autopsy)

And it affects roughly HALF the aged populaion; and does indeed affect some people as early as their 50s. Did it affect HALF the old agers who were in the over-70 bracket 25 or 30 years ago? I don't think so.