EXERCISE SLOWS DEVELOPMENT OF ALZHEIMER'S-LIKE BRAIN CHANGES IN MICE

Physical activity appears to inhibit Alzheimer's-like brain changes in mice, slowing the development of a key feature of the disease, according to a new study. The research demonstrated that long-term physical activity enhanced the learning ability of mice and decreased the level of plaque-forming beta-amyloid protein fragments -- a hallmark characteristic of Alzheimer's disease (AD) -- in their brains.

Results of this study, conducted by Paul A. Adlard, Ph.D., Carl W. Cotman, Ph.D., and colleagues at the University of California, Irvine, are published in the April 27, 2005, issue of "The Journal of Neuroscience".

Compared to the sedentary animals, mice that had exercised for 5 months on the running wheels had significantly fewer plaques and fewer beta-amyloid fragments (peptides) in the cerebral cortex and hippocampus, approximately by 50 percent. Additional studies, of exercised animals at 10 weeks old, showed that the mechanism underlying this difference began within the first month of exercise.

"From other research, it is known that in the aging human brain, deposits of beta-amyloid normally increase. This
study tells us that development of those deposits can be reduced and possibly eliminated through exercise, at least in this mouse model."