Back “in the day” the conventional wisdom was that, once you lost brain cells, those dead cells, unlike other cells in the body, would never regenerate. Most people, even fairly recently, are still misinformed that brain cells are “one-time only” cells. The message was and often still is, “Brain cells don’t grow back so, for heaven’s sake, don’t do anything to kill them!”
But now we know the brain does make new brain cells. It’s a process called neurogenesis and we’ve only really known about it since 1997, far too recent for this information to have made it into most school curriculae. And it was only in 2007 that we were sure neurogenesis happened in humans.1
Not only does exercise spur the brain to create new cells, it also sets off the production of the ultimate new brain cell nourishment: Brain-derived neurotrophic factor (BDNF).
BDNF is a protein that is considered to be a nerve growth factor. It’s found throughout the brain, but is primarily located in areas that are important to learning, memory and higher thinking.
Interesting, isn’t it, that exercise is such a boost for BDNF levels? (But note that BDNF levels drop due to air pollution exposure, so when you are exercising amidst heavy traffic, you may not get quite the BDNF boost you are hoping for.) We tend to separate exercise from intellectual pursuits, but here we see how intimately connected they are. Without exercise, you are at an intellectual disadvantage.
BDNF strengthens the connections between neurons, thereby building cell circuitry and nourishing cell functioning. One of the brain areas that is particularly rich in BDNF is called the hippocampus, and it’s a critical area of the brain for functioning related to emotion and memory. Since the hippocampus is part of your brain’s emotional circuitry, BDNF can be a link between physical movement and emotion.
1 – Ratey J. (2008) Spark: The Revolutionary New Science of Exercise and the Brain. New York: Little, Brown and Company.