Let’s Keep Moving!!!

Posted on April 22, 2012 by

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The Let’s Move! admonition that we have heard from First Lady Michelle Obama is bolstered  by a recent (4/18/12) New York Times Magazine article, entitled How Exercise Could Lead to a Better Brain, by Gretchen Reynolds, which reports the following: The latest neuroscience evidence suggests that exercise — physical exercise – does more to support and strengthen thinking than thinking does.

Why? Because the brain, like all muscles and organs, is a tissue, and its function declines with underuse and age. Beginning in our late 20s, most of us will lose about 1 percent annually of the volume of the hippocampus, a key portion of the brain related to memory and certain types of learning. But physical exercise seems to slow or reverse the brain’s physical decay, much as it does with muscles.

Until recently, scientists thought that humans were born with a certain number of brain cells and would never generate more. But they now know better. In the 1990s, using a technique that marks newborn cells, researchers determined during autopsies that adult human brains contained quite a few new neurons. Fresh cells were especially prevalent in the hippocampus, indicating that neurogenesis — the creation of new brain cells — was primarily occurring there. Even more heartening, scientists found that exercise jump-starts that process.

Significant evidence comes from several new studies of lab animals living in a variety of environments. It was discovered that the animals (mice) that exercised had healthier brains and performed significantly better on cognitive tests than the other mice. Those mice tested in surroundings that lacked exercise opportunities (running wheels) did not improve their brainpower in the complex, lasting ways that were being studied.

Animals that didn’t run, no matter how enriched their world was otherwise, did not become smarter. “They loved the toys,” but unless they also exercised, they did not become smarter.

One test concluded: “Only one thing had mattered, and that’s whether they had a running wheel.”  Animals that exercised, whether or not they had any other enrichments in their cages, had healthier brains and performed significantly better on cognitive tests than the other mice.

Just how exercise remakes minds on a molecular level is not yet fully understood, but research suggests that exercise prompts increases in something called brain-derived neurotropic factor (B.D.N.F), a substance that strengthens cells and axons, fortifies the connections among neurons and sparks neurogenesis. Scientists have found that after workouts, most people display higher B.D.N.F. levels in their bloodstreams.  

Most of these studies have involved running or other aerobic activities. But that exercise does not need to be exhausting to be effective for the brain.

The Times article concludes with this: “When a group of 120 older men and women were assigned to walking or stretching programs for a major 2011 study, the walkers wound up with larger hippocampi after a year. Meanwhile, the stretchers lost volume to normal atrophy. The walkers also displayed higher levels of B.D.N.F. in their bloodstreams than the stretching group and performed better on cognitive tests.

“In effect, the researchers concluded, the walkers had regained two years or more of hippocampal youth. Sixty-five-year-olds had achieved the brains of 63-year-olds simply by walking, which is encouraging news for anyone worried that what we’re all facing as we move into our later years is a life of slow (or not so slow) mental decline. “

Let’s keep moving!!!

(Go to this link: http://www.nytimes.com/2012/04/22/magazine/how-exercise-could-lead-to-a-better-brain.html for the complete Times article.)

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