New research suggests that "staying interested" in life through old age can mitigate symptoms of Alzheimer's disease:
[A] strong sense of purpose in life evidently strengthens or provides a higher level of what's known as "neural reserve" in the brain. "Reserve" is the quality that allows many physiological systems in the human body to sustain what the Rush [University] researchers call "extensive organ damage" before showing clinical deficits.
Neurobiologists specializing in aging have already determined that this concept also applies to the human brain, because most of us — regardless of whether we develop clinical symptoms of "Alzheimer's disease" or not – will accumulate harmful amounts of plaque and tangles in our brains as we age. Autopsies show that. What the Rush researchers' results indicate is that having a strong sense of purpose in life, especially beyond the age of 80, can give a person's brain the ability to sustain that damage and continue to function at a much higher level.