Regarding cardio exercise and brain function

Also from How Not to Die, by Michael Greger MD:

In a 2010 study published in the Archives of Neurology, researchers took a group of people with mild cognitive impairment—those who are starting to forget things, for example, or regularly repeating themselves—and had them engage in aerobic exercise for forty-five to sixty minutes a day, four days a week, for six months. The control group was instructed to simply stretch for the same time periods.

Memory tests were performed before and after the study. Researchers found that in the control (stretching) group, cognitive function continued to decline. But the exercising group not only didn’t get worse, they got better. The exercisers got more test answers correct after six months, indicating their memory had improved.

Subsequent studies using MRI scans found that aerobic exercise can actually reverse age-related shrinkage in the memory centers of the brain. No such effect was found in the stretching and toning control groups or a nonaerobic strength-training group. Aerobic exercise can help improve cerebral blood flow, improve memory performance, and help preserve brain tissue.