Exercise creates “brain of steel”

Posted October 7, 2007 at 12:00 PM by Megan Hueter

Section: In The News, His Health, Mental Health

Exercise can create a stronger, faster brain - said a recent article in the New York Times. Researchers are now looking into studies that show exercise improving the performance of the brain by boosting memory and cognitive processing speed.

The hot study was recently published by researchers Fred Gage and his team at the Salk Institute, who examined the brains of mice. Conventional knowledge says that after a brief stage early in life, the brain can no longer grow or improve and renew itself. This is because teh supply of neurons (brain cells) was believed to be fixed at birth. Cells die through aging and mental abilities decline steadily. The damage could not be repaired.

BUT Gage’s mice proved differently. Gage and his team injected mice with a chemical compound that works itself into actively dividing cells. The researchers thought they wouldn’t find such cells in the mice’s brain tissue, but they did. Up until the point of death, the mice were creating fresh neurons. This means their brains were repairing and making new cells.

But what’s interesting is that the brains of the athletic mice—in particular—showed many more new cells. These mice, the ones that scampered on running wheels, were producing two to three times as many new neurons as the mice that didn’t exercise.

Can it work on humans? Too find out, Gage and his team had obtained brain tissue from deceased cancer patients who had donated their bodies to research. While still living, these people were injected with the same type of compound used on the mice in Gage’s previous studies. (Pathologists injected them because they were hoping to learn more about how quickly the patients’ tumor cells were growing.) When Gage dyed their brain samples, he again saw new neurons. Like the mice, the humans showed evidence of neurogenesis. Since then, scientists have been finding more evidence that the human brain is not only capable of renewing itself but that exercise speeds the process.

Similarly, researchers at Columbia University published a study in which a group of participants began working out for an hour four times a week. After 12 weeks, they became more fit and healthy. Their VO2 max, the standard measure of how much oxygen a person takes in while exercising, rose—a lot.

But something else happened as a result of all those workouts: by looking at MRI tests, the researchers were able to see that more blood (almost twice as much as a non-exercising person) flowed to a part of the brain responsible for neurogenesis (growth of brain cells) - the hippocampus—the part of the brain that controls memory. Scientists suspect that the blood pumping into that part of the brain was helping to produce fresh the new brain cells.

As you get older, your brain gets smaller, and one of the areas most prone to this shrinkage is the hippocampus. Many neurologists believe that the loss of neurons in the hippocampus may be a primary cause of the cognitive decay associated with aging. So if exercise can help this, maybe if we all keep up our physical fitness, we’d be that much more intelligent?

Research sources and for more information: [NY Times]