Wanna stay mentally alert as you age? Exercise both the body and the brain.

If you want to keep your wits about you as you age, you need to work those wits—but you also need to work your body.

Exercise, particularly aerobic exercise is very important to brain function. That’s been known for some time, and the evidence keeps building. 

As far back as 2004, a Hawai`i study found that elderly adults who walk a lot have lower rates of dementia. The report in the Journal of the American Medical Association reviewed tests done on hundreds of elderly men, comparing their physical activity with rates of dementia.

“Our findings suggest that physically capable elderly men who walk more regularly are less likely to develop dementia,” wrote the authors of the study, Walking and Dementia in Physically Capable Elderly Men.

The Mayo Clinic Proceedings in 2011 stated the case clearly: “A rapidly growing literature strongly suggests that exercise, specifically aerobic exercise, may attenuate cognitive impairment and reduce dementia risk,” Mayo wrote. 

Scientific American was in there, too, with the headline, “Aerobic exercise bulks up hippocampus, improving memory in older adults.”

A 2010 study in the Proceedings of the National Academy of Science said regular aerobic exercise increased the size of the hippocampus, a part of the brain that tends to shrink with age. 

“Exercise training increased hippocampal volume by 2%, effectively reversing age-related loss in volume by 1 to 2” years, said this study.  

A 2014 study showed that specifically in elderly women, exercise increased the size of the hippocampus—the part of the brain associated with verbal memory and learning. 

That study, from the British Journal of Sports Medicine is here. 

A Finnish study in February of this year, 2016, found similar results: “Aerobic exercise, such as running, has positive effects on brain structure and function, for example, the generation of neurons (neurogenesis) in the hippocampus, a brain structure important in learning. 

That study, done on rats rather than humans, in the Journal of Physiology is here. 

And this article in the New York Times argues that it needs to be aerobic exercise, not just muscle-building work. 

Most of the work indicates that the effect of exercise isn’t huge but it’s real. 

Still, physical activity isn’t everything. You also need to exercise the brain directly.

The American Psychological Association says specific kinds of brain training can help stave off dementia. But not all brain training.

“The mistake some people make is thinking that all brain training is the same. Lumping all brain training together is like trying to determine the effectiveness of antibiotics by looking at the universe of all pills, and including sugar pills and dietary supplements in that analysis. You’ll find that some work and some do not. To then conclude that brain training does not work — or is not yet proven—is based on flawed analysis.” So says Jerri Edwards, PhD, of the University of South Florida, who led a study on the subject, published by APA, above.

Another study suggests intensive learning can actually cause chemical changes in the brain, increasing the amount of a protein that helps protect against memory loss, and even Alzheimer’s Disease.

"You're keeping the machinery going. It makes sense that the more time spent intensely focused on learning, the more your brain is trained to process information and that doesn't go away. That intense kind of learning seems to make your brain stronger," said Auriel Willette, an assistant professor of food science and human nutrition at Iowa State University. 

© Jan TenBruggencate 2016