Exercise is largely the modern day substitute for work/survival associated with intense physical activity. This activity was not only essential for survival providing access to food and other essential resources but also has been important in optimizing physiologic functioning essential to survival.
Physical activity activates the expression of “neurotrophic factors” in the brain. Most noted of this family of signaling factors is brain derived neurotrophic factor, or BDNF. Neurotrophic is defined by the two words it is derived from. Neuro refers to nervous system cells including brain neurons. Trophic refers to growth and function stimulation. Neurotrophism is an ongoing process needed to maintain brain cell health and function.
A recent study randomized 95 adults to an exercise training group, a cognitive training group, a combined exercise and cognitive training group and a control group who did not participate in either training. Exercise training produced significant memory improvements as did the cognitive training compared to the controls. The combined exercise and cognitive training group improved memory function to an even greater extent than either the exercise alone or cognitive training alone groups.
The images to the left show differences in brain activity on functional MRIs in subjects regularly exercising versus those who are sedentary. Exercise induces stimulus to the brain to increase activity and synaptic formation, the formation of connections that allow neurons to communicate with each other. These increased connections translate to higher levels of function such as memory processing.
The effect of exercise correlated with increased BDNF levels. The researchers concluded that both cognitive training and exercise training improve memory function. Combining the two has an even greater effect which appears to be the result of stimulating the neurotrophic factor BDNF.
The study relates to important points in the Bredesen Protocol™ for Alzheimer’s. The protocol derived its success from the fact that it combines multiple treatments that have synergistic effects on brain restoration. This is in sharp contrast to the typical drug treatments that focus on one mechanism resulting in no significant effect on the disease outcome. The disease is multifactorial in origin, and treatment needs to be approached similarly.
The second point relevant to the Bredesen Protocol™ is that the disease has to be approached from two different areas. The first is to find and treat the factors that drive the disease. These are diverse and are addressed in the extensive testing that precedes treatment. Once the factors that are responsible for injuring the brain are corrected, brain volume and function must be rebuilt using a broad program of neurofeedback, cognitive training, exercise and sleep restoration.
There is a tendency to question if daily exercise is essential. Our ancestors of long ago were thought to be physically active in pursuit of food and other survival essentials for 12 or more hours daily. While modern humans are more than 99% genetically identical to these ancestors and therefore share their same activity dependent physiology, our physical activity levels have diminished to only a fraction of our predecessors. This has not been without serious health impacts including on brain health.
Attention to lifelong exercise is ideal. However, if that has not been the case, properly managing exercise once brain dysfunction and disease have developed can help in restoring function.
Heisz et al. The Effects of Physical Exercise and Cognitive Training on Memory and Neurotrophic Factors . Journal of Cognitive Neuroscience, 2017:29;1895-1907.