Researchers at Columbia University have demonstrated that common age-related memory loss is distinct from Alzheimer's disease. As importantly, you can reverse this loss. Well, if you're a mouse, you can.
In the end, it may turn out that attacking today's biomarkers may not prevent Alzheimer's. The answer, though, won't be known unless the FDA revises its rules, a gamble we may want to take given the alternative.
While cardio respiratory fitness has not yet been proven to have a direct effect on halting the symptoms of Alzheimer's disease, if a causal connection is found it would have a huge impact on our aging population, as well as the health of our economy.