Imagery Training 3: What is BDNF and Why is it so Hot?

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BDNF UNCOVERED

What is BDNF?

BDNF is a part of the neurotrophin family and stands for Brain-Derived Neurotrophic Factor; a protein encoded by the BDNF gene that influences activity and survival of neurons as well as network synthesis in the brain (1).

Current research suggests that BDNF is linked to a process called neuroplasticity, a term used to describe the ability of the brain to continue changing and developing over time. This is a relatively new concept since for many years it was believed that the brain was fixed and could not change after a particular developmental stage (1).

BDNF protein is located throughout the body but mostly concentrated in the prefrontal cortex, an area of the central nervous system that directs decision making, emotional regulation, memory and reasoning (2). When adequately produced and encoded, BDNF can increase resiliency, quality of life and have a positive effect on brain health.

Since BDNF has a complex genetic structure, there is room for different forms of this gene to occur. For example, Valine (Val/Val) and Methionine (Met/Met) are commonly studied outcomes of the BDNF gene (3). More recently, researchers have been interested in a particular variant of BDNF called the Val66Met polymorphism. This polymorphism occurs when Valine and Methionine are expressed together, which has been associated with adverse health effects such as increased stress sensitivity and decreased BDNF availability (3). For the purposes of this article we will discuss Val/Val and Val66Met in terms of high BDNF producers (Val/Val) and low BDNF producers (Val/Met) (4).  Basically, if your BDNF gene contains a methionine variant, you are expected to produce less BDNF.  Many genomic tests available today will test for this particular genomic variant, also known as a SNP (single-nucleotide polymorphism).

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Why is BDNF important to consider?

BDNF is a gene that affects our mental health and wellbeing. In studying BDNF, researchers have looked at the effect it has on mood disorders, cognitive functioning and neurodegenerative diseases.

 

Mood Disorders

A study looking at the effect of BDNF on mood disorders found low BDNF producers to be more susceptible to anxiety and depression, in comparison to high BDNF producers (3). Moreover, low BDNF producers appear to have a lessened ability to adapt to daily life stressors, especially stressful social situations (i.e. conflict with a co-worker). To illustrate this, Wichers et al. (2008) found that low BDNF producers displayed significantly higher negative affectivity in response to social stress, compared to high BDNF producers. These findings suggest that it may be more challenging for low BDNF producers to resolve difficult social conflicts, while maintaining positive emotions.

 

Cognitive Functioning

BDNF demonstrates an important role in cognitive functioning as it affects the brain’s ability to adapt, respond and develop over time. The production of new neurons in the adult brain primarily occurs in the hippocampus, where BDNF is largely found, suggesting that BDNF is a factor associated with memory and learning (2). To explore this hypothesis, studies have investigated whether BDNF plays a role in cognitive functioning during sleep deprivation. A study conducted by Grant et al. (2018) found that low BDNF producers perform significantly poorer on a Stroop task measuring error rate and reaction time, compared to high BDNF producers. More specifically, low BDNF producers made more errors on the Stroop task during sleep deprivation, and exhibited longer response times regardless of sleep deprivation, compared to high BDNF producers (2). This research suggests that BDNF genotype may have an impact on one’s cognitive flexibility and performance during both wakefulness and sleep deprivation.

 

Mental Health

BDNF has been linked to mental health status and various neurodegenerative diseases like Alzheimer’s disease (1). Recent research has focused on looking at how and why this relationship occurs.

Studies reveal that when stress increases inflammation in the body, it subsequently decreases BDNF availability and utilization (1). As a result, stress-induced inflammation can impair the processes involved in the survival and maintenance of neurons and neuronal connections. The consequences of this can be seen in individuals suffering from depression, as postmortem brain reports show increase levels of inflammation and decreased levels of BDNF (1, 3). Additionally, BDNF is found to be lowered in individuals with Alzheimer’s disease (6). This may be linked to pro-inflammatory cytokines, as they are shown to negatively impact the hippocampus (i.e., memory) and increase cell death in the brain, both of which are factors involved in the development of Alzheimer’s disease (1). This suggests a significant interaction between BDNF, stress and inflammation on mental health status.

BDNF has also been explored as a possible genetic link involved in concussion recovery. This is because BDNF has demonstrated a significant role in cognitive performance and neuroplasticity (2). For example, a study looking at the effect of BDNF on cognitive performance in patients with mild traumatic brain injury (mTBI) found that Met carriers performed significantly poorer on tasks related to memory, executive functioning and overall performance when tested 10 hours post-injury and 6 months later, compared to Val carriers (5). This suggests that BDNF genotype may influence the course of recovery in individuals with mTBI.

Overall, this research indicates that higher levels of BDNF is beneficial for mental health. Thus, efforts to increase BDNF should be considered as a proactive strategy to boost and/or maintain brain resiliency over time.

 

Wellbeing

Stress management techniques have demonstrated favourable effects on BDNF and psychological functioning. A recent study explored the effects of yoga and meditation on levels of stress and BDNF. Results found that after a 3-month yoga and meditation retreat, BDNF levels increased 3-fold from pre to post (7). Participants also showed improvements in adrenocortical activity, indicating an increase in resiliency to stress (7). Further studies support these findings as meditative yoga practice have been found to increase BDNF, mediate heart rate and improve mood disorders such as depression (8). Thus, additional stress management techniques should be explored as they are shown to increase psychological wellbeing.

Imagery Training has demonstrated the ability to mediate stress appraisal (i.e., heart rate) and increase cognitive performance in individuals (9). Therefore, in line with the above research on meditation and BDNF levels, it is reasonable to hypothesize that Imagery Training is associated with increased levels of BDNF. Imagery can be used by individuals who do not prefer to practice yoga or meditate as it achieves the same outcome; decreased stress and inflammation in the body.

In summary, future research should look at the link between Imagery Training and BDNF as it could be used as an effective strategy to increase BDNF levels. Increased levels of BDNF are associated with improvements in mood disorders, resiliency toward stress, and overall wellbeing. BDNF may serve as a neuroprotective mechanism that can support individuals in maintaining brain health throughout adulthood and into the course of aging.  

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How can I increase my BDNF?

Here are some sure-fire ways to boost your BDNF:

  • Aerobic Exercise
  • Meditation
  • Intermittent Fasting
  • Adequate Sleep (7-8 hours)
  • Omega 3 Fatty Acids
  • Avoid sugar and processed foods

Kristin H Kretschmer BA  Hons. Psychology, CNP, is a Vancouver-based Holistic Nutritionist and Wellness Counsellor specializing in stress management and digestive health. Her passion is to create awareness around the mind-gut connection and support people in reaching their health goals through nutrition, movement and coping skill development. 

Dr. Jason Marr ND arms urban professionals and students of professional studies with the pragmatic tools to maximize performance, productivity and resilience.  Using an evidence-informed, holistic and integrative approach, Dr.Marr is a productivity and performance coach for anyone who is striving to be awesome.  


References

  1. Calabrese, F., Rossetti, A., Racagni, G., Gass, P., Riva, M., & Molteni, R. (2014). Brain-        derived neurotrophic factor: A bridge between inflammation and neuroplasticity.                                    Frontiers in Cellular Science, 1-7.
  2. Grant, L. K., Cain, S. W., Chang, A.-M., Saxena, R., Czeisler, C. A., & Anderson, C. (2018). Impaired cognitive flexibility during sleep deprivation among carriers of the brain            derived neurotrophic factor (BDNF) Val66Met allele. Behavioural Brain Research, 51-     55.
  3. Wichers, M., Kenis, G., Jacobs, N., Derome, C., Vlietinck, R., Myin-Germeys, I., & ...Van-   Os, J. (2008). The psychology of psychiatric genetics: evidence that positive emotions in                       females moderate genetic sensitivity to social stress associated with the BDNF val66me       polymorphism. Journal of Abnormal Psychology, 699-704.
  4. Cohen, J. (2018, February 9). All you need to know about BDNF and natural ways to   increase it. Retrieved from Selfhacked: https://ww.selfhacked.com/blog/a-comprehensive-list-of-natural-ways-to-increase-bdnf/
  5. Narayanan, V., Veeramuthu, V., Ahmad-Annuar, A., Ramli, N., Waran, V., Chinna, K., & ...   Ganesan, D. (2016). Missense Mutation of Brain Derived Neurotrophic Factor (BDNF)                  Alters Neurocognitive Performance in Patients with Mild Traumatic Brain Injury: A                     Longitudinal Study. PLOS One, 1-15.
  6. Fumagalli, F., Racagni, G., & Riva, M. (2006). The expanding role of BDNF: a therapeutic      target for alzheimer's disease. The Pharmacogenomics Journal, 8-15.
  7. Cahn, R., Goodman, M., Peterson, C., Maturi, R., & Mills, P. (2017). Yoga, meditation and mind-body health: Increased BDNF, cortisol awakening response, and altered inflammatory marker expression after a 3-month yoga and meditation retreat. Frontiers in Human Neuroscience, 1-13.
  8. Pal, R., Singh, S. N., Chatterjee, A., & Saha, M. (2014). Age-related changes in             cardiovascular system, autonomic functions, and levels of BDNF of healthy active males:          Role of yogic practice. doi: 10.1007/s11357-014-9683-7     
  9. Williams, S. E., Veldhuijzen van Zanten, J., Trotman, G. P., Quinton, M. L., & Ginty, A. T.   (2017). Challenge and threat imagery manipulates heart rate and anxiety responses to             stress. International Journal of Psychophsiology, 111-118.