Physical activity (like your morning walk or run) generates BDNF (brain-derived neurotropic factor), a powerful neurohormone that stimulates the growth of new neurons in your cerebral cortex. BDNF not only grows new brain cells but also enhances memory, improves IQ, and reverses cognitive impairment.
BDNF invigorates nerve cells in three ways. First, it stimulates neurogenesis, the growth of new nerve cells from your own stem cells. Second, it enhances neuroplasticity—your nervous system’s ability to reorganize your nerve pathways. Last, but definitely not least, it amplifies synaptoplasticity—making new synaptic interconnections between neurons by encouraging them to grow new tendrils that reach out and make new connections with nearby nerve cells. So BDNF gives you new brain cells that are more open and flexible and more communicative.
The BDNF generated during exercise also increases the size of your brain. Each brisk walk or run adds just a bit of gray matter, but researchers have shown that the cumulative effect of regular jogging generates an annual 2 percent gain in brain size and cell count. Couch potatoes are headed in the other direction.
Given the above information, it should come as no surprise that the brains of Alzheimer’s patients have been found to contain significantly lower levels of BDNF than the brains of healthy patients and that restoring BDNF reverses neurodegenerative conditions.
BDNF, neurogenesis, neuroplasticity, and synaptoplasticity are under your control, and you can choose to enhance them with diet, supplements, and exercise to prevent and reverse dementia. An overwhelming number of research studies tell us that high-level brain fitness is associated with increased production of BDNF and its ability to unleash neurogenesis, neuroplasticity, and synaptoplasticity. These, in turn, are virtually always associated with increased hippocampal volume, better memory, across-the-board cognitive enhancement, and improved overall brain function.
Exercise, in particular, turbocharges BDNF production. A modest amount of moderate-intensity physical activity is necessary to take advantage of the brain’s natural capacity for plasticity, resulting in improved cognitive performance, better academic achievement, and reduced dementia risk.