"Exercise training increases size of hippocampus and improves memory, "
PNAS 2011 108 (7) 3017-3022; published ahead of print January 31, 2011
In the Proceedings of the National Academy of Sciences study, "scientists started with 120 elderly volunteers who were relatively inactive but did not have dementia. Half were randomly assigned to begin walking 40 minutes a day, three days a week for a year while the remainder only stretched and performed toning exercises for the same time period. After 12 months, the group that walked showed an average 2% growth in the hippocampus compared with when they began, while the control groups suffered a more than 1% shrinkage in the same region compared with when the study started.
“If you estimate the change at an individual level,” says study co-author Arthur Kramer of the University of Illinois, “a yearlong exercise program can turn back the clock about two years with respect to the volume of the hippocampus.” "
Read more: http://healthland.time.com/2011/01/31/want-to-improve-your-memory-take-a-walk/#ixzz1Euftky36