Andart

Healthy, wealthy and wise... at least two out of three

http://www.pnas.org/cgi/content/abstract/0400266101v1
Cardiovascular fitness, cortical plasticity, and aging by Stanley J. Colcombe, Arthur F. Kramer, Kirk I. Erickson, Paige Scalf, Edward McAuley, Neal J. Cohen, Andrew Webb, Gerry J. Jerome, David X. Marquez, and Steriani Elavsky

That ill health is bad for cognition is fairly obvious, but does good health help thinking? The answer seems to be a fairly strong 'yes'. Animal experiments demonstrate that aerobic training improve how much blood is supplied to the brain, synaptic growth and even the emergence of new neurons. Trained animals have more adaptable brains that learn better, especially in old age. This paper demonstrates that the same is true for humans.

The researchers first tested older people with a reaction-time/attention task, and found that people with better cardiovascular fitness did better on the task. Then they divided a group of test subjects into two groups, one that got aerobic exercise and one that just got stretching and toning. It turned out that the exercised people did 11% better on the task after six months compared to just 2% better for the stretching people.

In addition, there were some interesting changes in brain activation. Fit or trained people showed higher activations in the prefrontal areas responsible for preventing distraction and in the parietal regions involved in hand-eye-space integration. There were also effects in the anterior cingulate cortex, the link between prefrontal thinking and the attentional-emotional systems of the brain.

Most likely these effects are mediated through growth factors (and perhaps a bit more blood and oxygen). Insuline like growth factor (IGF-1) is one such potential factor. It has neuroprotective effects, promotes the growth of new cells and appears to reduce the amyloid-beta protein involved in Alzheimer's disease. It has also been successfully inserted into mice muscles using gene therapy to prevent age-related muscle loss and improve healing. Maybe it is also a good idea against age-related mental loss.