Still not walking? Your brain wants you to cover 6 miles every week!

We already discussed the need to exercise to preclude disease (Parkinson’s, cancer, autoimmune).  Now, there’s more reasons to get walking.  Dr. Kirk Erickson (University of Pittsburgh) and associates just published results in Neurology from  a follow-up from the Cardiovascular Health Cognition Study.  They reported that walking six miles weekly not only protects the grey matter of the brain- but it also helped retain memories.

The study involved 299 dementia free patients (mean age 78), who tracked how many weeks they walked over the nine-year period.  At the end of the nine-year period, these participants had undergone MRI scans.  These participants were then re-examined and studied four years later (the subject of this publication). The study participants walked from 0 to 300 blocks weekly (mean distance: 56.3).  The researchers found that walking 72 blocks (6 miles) was a critical threshold.  While some 40% of the participants did develop dementia, walking the 6 miles did preserve the grey matter and reduced the risk for cognitive impairment by at least 2 orders of magnitude. (73 of the 299

Image via Wikipedia

(24%) walked the threshold distance or beyond.)  Interestingly, the researchers broke the participants into smaller subsets to see if longer walks improved the results; however, they found no significant cognitive improvement among those walking longer distances.  Moreover, the grey matter volume in the hippocampus, frontal gyrus, or parahippocampal gyrus did not correlate with any change in cognitive impairment. (Please note that ONLY cognitive impairment and brain matter were studied here; there could- and should- be cardiovascular improvements from the longer duration walks, since a 6 mile walk does not equate to the recommended weekly 150 minutes of physical activity to achieve good health.)