Moral of the story: The evidence continues to evolve as we learn more about Alzheimer's.  Mentally stimulating activity can delay onset, but once onset does occur, patients deteriorate most rapidly.

Source: AMA Morning Rounds 9/2/2010

Mentally stimulating activities may delay, not prevent, signs of Alzheimer's.

ABC World News (9/1, story 8, 0:30, Sawyer) reported, "There is a new study that found mentally stimulating activities," such as "reading and solving puzzles...can indeed delay the outset of Alzheimer's disease, but not prevent it for good."

        "Poring over crossword puzzles, reading, and listening to tunes may slow or delay brain decline at first, but being mentally active might speed up dementia once it hits," USA Today (9/2, Marcus) reports. According to Robert Wilson, PhD, of the Rush University Medical Center and the lead author of the study published online Sept. 1 in the journal Neurology, "The person who has had a more mentally stimulating lifestyle may have more signs of disease in his brain, but the brain has been able to compensate for it better." While "researchers don't fully understand why active-minded people suffer such a rapid decline once they develop Alzheimer's...the study shows the advantages of using your brain because of the early benefits."

        The Los Angeles Times (9/1, Healy) reported that in the "study of 1,157 Chicago-based seniors who were followed for an average of just over 11 years," investigators found that "the steepest downward trajectories belonged to those who had been diagnosed with Alzheimer's disease, but who had reported high levels of mental engagement at the outset of the study." Meanwhile, "fellow Alzheimer's sufferers who had not sought out much intellectual stimulation at the study's outset showed a more gradual decline in their function."

        The Washington Post (9/1, Stein) "The Checkup" blog reported that, according to Wilson, "those who have been mentally active are able to maintain their thinking abilities despite whatever damage is occurring in their brains for much longer than those who are not," probably because they have achieved some cognitive reserve. Therefore, "when the damage finally does get so bad that it starts to show itself, these people are actually much farther along and so go downhill much more quickly."

        The CNN (9/1, Landau) "The Chart" blog reported, "That's not necessarily a bad thing, if you consider quality of life issues, researchers say." The blog entry quoted Wilson as saying, "At the end of the day, you spend less of your lifespan in that demented state."

        HealthDay (9/1, Phillips) noted, "According to the authors, the results suggest that mental exercises help prevent the onset of dementia, but only if they're started before signs of cognitive impairment appear -- after that point, the brain is probably too damaged for such interventions to make a difference."

        New discovery reveals potential Alzheimer's medication target. The New York Times (9/2, A25, Kolata) reports that a discovery made by scientist Paul Greengard, PhD, appears to reveal "a new potential drug target that...could slow or halt the devastating effects" of Alzheimer's disease, according to research published in the journal Nature. Greengard has discovered what he calls the gamma secretase activating protein (GSAP), which tells gamma secretase to make produce beta amyloid. Working with genetically engineered mice, Greengard "blocked the gene for" GSAP. Notably, those mice stayed healthy and did not go on to develop beta-amyloid brain plaques that are characteristic in Alzheimer's disease.

        The CNN (9/1, Willingham) "The Chart" blog reported that modified forms of the medication Gleevec (imatinib mesylate), used to treat certain forms of leukemia and gastrointestinal cancers, have "the ability to bind" to GASP and even reduce "beta-amyloid production." Unfortunately, Gleevec "does not cross the blood-brain barrier," but researchers believe that it will someday be possible to create medications that "target GSAP, but do not have that limitation."