Exercise seems to help ward off Alzheimer's disease, several studies show

• 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.