April 26, 2005 - The new research demonstrates that long-term physical activity enhances the learning ability of mice and decreases the level of plaque-forming beta-amyloid protein fragments - a hallmark characteristic of Alzheimer's disease (AD) - in their brains.
This is the latest of several studies in recent years claiming exercise can slow Alzheimer's and dementia.
(For other studies see box on left.)
March 15, 2005 -- Two of the diseases most feared by senior citizens -- Alzheimer's and Parkinson's -- may be prevented or slowed by exercise, according to two recent studies.
The Alzheimer's study showed that middle-aged people taking regular exercise at least twice a week could reduce their risk of developing Alzheimer's disease by 50 percent.
April 14, 2005 - The variety of leisure and physical activity one engages in -- and not its intensity in terms of calories expended - may reduce dementia risk in older people, according to researchers at Johns Hopkins.
To directly test the possibility that exercise (in the form of voluntary running) may reduce the cognitive decline and brain pathology that characterizes AD, the study utilized a transgenic mouse model of AD rather than normal mice.
Initially, young mice (6 weeks or 1 month of age) were placed in cages with or without running wheels for periods of either 1 month or 5 months, respectively.
The animals that exercised learned the task faster.
Thus, the mice that used the running wheels for 5 months took less time than the sedentary animals to find the escape platform.
They compared the levels of plaques, beta-amyloid fragments, and amyloid precursor protein, a protein found throughout the body and from which the beta-amyloid peptide is derived.