Brain Derived Neurotrophic Factor: A Protective Protein for Concussions
Concussion awareness in the NFL is already a widely discussed issue and with the 2020 NFL draft having recently concluded, the topic is creating even more noise. Despite the NFL having changed the rules to inflict more severe penalties for deliberate helmet-to-helmet hits, the statistics still reveal an increase in concussion rates in 2019.
When a concussion occurs, the brain is subject to a rollercoaster of trauma. Neuron function is impaired to a point where the ability to send signals and communication with other brain cells could be permanently lost. However, research has continuously shown that exercise promotes the growth of new brain cells by producing a protein called Brain Derived Neurotrophic Factor (BDNF). Interestingly, this protein also has a protective effect to the brain when it comes to brain injuries.
This article will provide an outline of the neurological effects of exercise, an overview of BDNF and its important role in concussions.
How does exercise neurologically impact the brain?
Direct links have been made between exercise and overall brain health. Exercise has been shown to improve cognitive function, memory, attention and the ability to learn. More specifically, exercise is beneficial because it improves neural connections and promotes neurogenesis, or the creation of neurons (Vecchio et. al, 2018). Furthermore, exercise has been proven to even change the structure of the brain. For instance, it has been shown to increase the volume of the hippocampus, which is the brain’s learning and memory centre. An increase in hippocampal volume can slow the effects of Alzheimer’s (Den Ouden, Lauren et. al, 2018).
So how is exercise able to have so many positive effects on the brain? One way is through the increased production of a protein called Brain Derived Neurotrophic Factor (BDNF).
What is Brain Derived Neurotrophic Factor (BDNF)?
All humans are born with a BDNF gene which provides instructions for making a protein found in the brain and spinal cord called Brain Derived Neurotrophic Factor (BDNF). BDNF improves the functions of neurons, encourages new neurons to grow and protects neurons from stress and cell death. Think of BNDF as fertilizer for your brain cells!
The BDNF protein performs its function at the synapses. Synapses are where cell to cell communication happen. Synaptic plasticity occurs when the synapses change and adapt in response to new experiences. Synaptic plasticity enables us to take in and remember new information. BDNF is vital in regulating synaptic plasticity.
Brain trauma, such as from a concussion can cause one’s levels of BDNF to deplete, which in turn can lead to low cognitive function. Patients with Alzheimer’s, learning disabilities, and depression report abnormally low levels of BDNF. (Lima, Bruno et. al, 2019).
How do we increase our level of BDNF protein?
Exercise
Healthy diet
Vitamin D
Omega 3
BDNF and Exercise
Research shows a correlation between exercise, the production of BDNF and increased neurogenesis (Liu, 2018). A study comparing sedentary versus aerobically exercised rats throughout their lifespan found that the rats who exercised had significantly increased levels of BDNF. These rats showed improved cognitive function. Upon further investigation, it was discovered that they had larger hippocampus (Pietrelli, 2018). However, it is important to note that too much of anything can be unhealthy! Exercise is a stressor on the body and overdoing it can have the opposite affect and can actually cause the hippocampus to shrink (Barnes, 2018).
What can decrease levels of BDNF protein?
Obesity
Chronic stress
Sleep deprivation
Poor diet
BDNF and Concussions: Exercise for the Win
BDNF protein levels can decrease as a result of high levels of stress. Concussions can decrease levels of BDNF as a result of the tremendous physical and psychological stress they inflict on the body (Monteiro et. al, 2017). Thus, BDNF is a useful biomarker for determining whether or not a person has healed from a concussion. If a person consistently shows low levels of BDNF long after getting a concussion, it can be an indication of an incomplete recovery. These people are susceptible to suffering from concussion symptoms long after the fact (Korley, 2016).
Although it is assumed that you should rest when healing from a concussion, evidence suggests that low intensity exercise can be extremely beneficial (due to neurogenesis) (Lawrence, 2018). Getting moving is often the most important factor in starting to feel more normal after a concussion.
Conclusion: The Higher, The Better
Given the proven health benefits of high levels of BDNF, exercise is critical in the post-concussion recovery phase. The higher your BDNF levels are to begin with, the better you are protecting yourself from anything that might decrease your body’s ability to produce this vital protein.
References:
Vecchio, L. M., Meng, Y., Xhima, K., Lipsman, N., Hamani, C., & Aubert, I. (2018). The Neuroprotective Effects of Exercise: Maintaining a Healthy Brain Throughout Aging. Brain plasticity (Amsterdam, Netherlands), 4(1), 17–52. https://doi.org/10.3233/BPL-180069
Lima Giacobbo, B., Doorduin, J., Klein, H. C., Dierckx, R., Bromberg, E., & de Vries, E. (2019). Brain-Derived Neurotrophic Factor in Brain Disorders: Focus on Neuroinflammation. Molecular neurobiology, 56(5), 3295–3312. https://doi.org/10.1007/s12035-018-1283-6
Liu, P. Z., & Nusslock, R. (2018). Exercise-Mediated Neurogenesis in the Hippocampus via BDNF. Frontiers in neuroscience, 12, 52. https://doi.org/10.3389/fnins.2018.00052
Pietrelli, A (2018). Aerobic exercise upregulates the BDNF – Serotonin systems and improves the cognitive function in rats. DOI10.1016/j.nlm.2018.05.007
Barnes, J. N., & Corkery, A. T. (2018). Exercise Improves Vascular Function, but does this Translate to the Brain?. Brain plasticity (Amsterdam, Netherlands), 4(1), 65–79. https://doi.org/10.3233/BPL-180075
Monteiro, B. C et. al (2017). Relationship Between Brain-Derived Neurotrofic Factor (Bdnf) and Sleep on Depression: A Critical Review. Clinical practice and epidemiology in mental health : CP & EMH, 13, 213–219. https://doi.org/10.2174/1745017901713010213
Korley, Frederick K et al. (2016). Circulating Brain-Derived Neurotrophic Factor Has Diagnostic and Prognostic Value in Traumatic Brain Injury. Journal of neurotrauma, 33(2), 215–225. https://doi.org/10.1089/neu.2015.3949
Den Ouden, Lauren et al. “The Influence of Aerobic Exercise on Hippocampal Integrity and Function: Preliminary Findings of a Multi-Modal Imaging Analysis.” Brain plasticity (Amsterdam, Netherlands) vol. 4,2 211-216. 26 Dec. 2018, doi:10.3233/BPL-170053
Lawrence, D. W., Richards, D., Comper, P., & Hutchison, M. G. (2018). Earlier time to aerobic exercise is associated with faster recovery following acute sport concussion. PloS one, 13(4), e0196062. https://doi.org/10.1371/journal.pone.0196062