Can a Transfusion from an Exercising Person Convey Brain Health Benefit?

At least in mice, maybe it does.

On October 19 of last year, we cited an article in the Scientific American blog site regarding, among other things, how aerobic exercise fights Alzheimer's disease and resultant dementia.  One of the points the article made is that we should look for ways to artificially create the same conditions in the brain that exist during physical exercise in people subject to potential or actual Alzheimer's disease.  This would be great for couch potatoes, but more importantly, for people who may be too weak to do the kind of exercise that would help them.

Until now, I've seen no ideas proposed for how this might be done.  Until this morning.  There was an article in this week's issue of ALZForum regarding research with mice showing that transfusions of blood plasma from exercising mice promoted brain cell growth in sedentary mice.  No one has tried it yet, but this suggests that transfusions of blood plasma from exercising humans could retard the initiation and progression of Alzheimer's disease in other humans subject to Alzheimer's disease.  (Of course, even if this works, it would be hard to implement on any kind of scale.)

One thing that surprised me in the article was that they never mentioned the brain-derived neurotrophic factor (BDNF) that is usually credited with improved cognition from aerobic exercise.  Instead, they mentioned that there were other proteins generated during exercise in a variety of organs in the body that encourage the generation of new brain cells.  These go into the blood and end up in the brain.  The article cited rises in the concentration of a protein called clusterin in exercising people with mild cognitive impairment.  Clusterin fights inflammation and otherwise helps cells survive in hostile environments.  (Unfortunately, it can help cancer cells survive chemotherapy.)

The article cited research with exercising humans with memory loss which found increases in clusterin in their blood.  The research did not explore changes in cognition as a consequence of this.  I'm not sure if that would have accomplished much, since I don't know how you would separate the influence of BDNF and other factors as causes of improvement.  There are just so many ways in which physical exercise promotes brain health.