A growth-factor compound produced in our brains and muscles is emerging as having potentially mitigative effects on neurological disease, metabolic dysfunction, and even mood irregularities.
Furthermore, the methods for increasing the production and circulation of this growth factor, known as brain-derived neurotrophic factor (BDNF), are often simple and straightforward.
Research on how to extend lifespans and healthspans, and how to avoid the dozens of chronic diseases that kill millions every year is now more and more centered around how to augment the production of naturally-occurring compounds in our bodies, particularly through activities like sleep or exercise.
One such compound is BDNF, which effects not only pathology in the brain, but elsewhere as well.
BDNF literature has shown positive affects on mental health disorders and addiction, a reduced risk of neurodegenerative disease, and an increased proficiency in memory retention and learning.
Other strange and unexpected effects have also been shown, such as reduced appetite, improved markers for diabetes, and more.
How it works to do these things, as well as how its production is increased, is something World at Large will dive into through one of our special 2-part reports.
BDNF is sort of a ‘missing link’
BDNF is from a family of proteins called neurotrophins, in which it holds status as by far the most plentiful. Its simple description would be that it helps create new neural synapses — structures that allow neurons to pass electrical signals to each other. It’s produced primarily in the brain, but also in other organs like the liver.
BDNF is one of those compounds that could be behind many of the therapeutic benefits from things like exercise, sauna-use, and taking probiotics, which are well-known to correlate with better health outcomes. These activities increase BDNF, which as a compound correlates with the same increased health outcomes.
Is it that exercise helps reduce the risk of neurodegeneration, or that exercise increases production of BDNF, which is shown to reduce risk of neurodegeneration?
The answer to this quasi chicken/egg “what came first” question is not yet known, but what is know are many of the affects which BDNF has in the brain.
BDNF and mental acuity
For younger people, BDNF can be used like a tool for work, stress, and study, as it is shown in papers to improve cognitive function, hippocampal or short-term memory, learning speed and retention, mental clarity, as well as improving cases of mental health disorders like depression and anxiety.
While difficult to ascertain, plenty of evidence exists to suggest that lower-levels of BDNF result in depressive symptoms, and that increased BDNF levels is not only found in those who recovered with SSRI-assisted therapy, but that therapy patients without increased levels of BDNF after two weeks had a statistically significant rate of failure.
This was based on a meta-analysis of about 11 studies, while another meta-analysis of over 1,100 patients found a similar story in anxiety, particularly in patients with OCD, though the conclusion was muddied by several factors.
One area in which the claim that increased BDNF carries benefits is undisputed is synaptic plasticity and memory. This was found to be true in areas as diverse as a yoga retreat, the dance floor, and the classroom.
36 participants at a three month yoga and meditation retreat were observed to have 3-times the normal circulating levels of BDNF, while self-reported scores before and after the retreat for depression and anxiety fell by 60%. Mental clarity and mindfulness were also reported to be higher, perhaps suggesting a correlation with BDNF.
The results of eight weeks of mental training described in a paper as working memory, processing speed, and error minimization, showed improvements of 22%, 10%, and 19% respectively in a study cohort of old women with mild cognitive impairments. Their blood-plasma BDNF levels had increased 26% over placebo.
BDNF is also associated with increased satiety, and reducing one’s caloric intake increases BDNF, aligning it with some of the purported mental benefits of caloric restrictive, or ketogenic diets.
BDNF and neurological disease
A mouse model showed that mice which exercised voluntarily for one-week, needed less time to complete the task of finding the end to a memory water maze than mice who were sedentary. However when the researchers blocked BDNF receptors in their brains, the mice were denied all observable benefits which exercise had just conferred to their powers of memory.
“By inhibiting BDNF action we blocked the benefit of exercise on cognitive function, such that the learning and recall abilities of exercising animals receiving the BDNF blocker were reduced to sedentary control levels,” wrote the authors.
BDNF has shown promise, in rat, primate, and human studies, as both a measuring stick and even a treatment in several neurological disorders such as Parkinson’s, which results in tremors, slow movement, reduced coordination, and eventually death.
Rats that were loaded with BDNF in their dopamine-pathway neurons during early-stage Parkinson’s showed increased grooming habits, further distance traveled, and time spent walking, while monkeys injected with BDNF directly showed improvements in motor function, reduced neuronal cell loss, and an overall slower progression of Parkinson’s.
In humans, BDNF was predicted to work as a useful early warning system for Parkinson’s disease.
Alzheimer’s is the most common neurodegenerative disease in the world, and the leading cause of dementia. Beta-amyloid plaques entangle themselves around neurons, particularly in the memory centers of the brain.
A post-mortem examination of human brains of Alzheimer’s patients, showed BDNF levels were barren in many of the regions where the disease congregates, such as the hippocampus, claustrum, and amygdala. Another study of 2,000 individuals found that each standard-deviation lower that a participant of any of the observed groups were in levels of BDNF, they were found to have a 23% increase in risk for developing dementia.
This was particularly observed in women, where lower BDNF levels had a statistically significant correlation to Alzheimer’s development.
BDNF effects synaptic and neuron plasticity, a key hallmark of healthy and advanced brain function and health. It has a wide variety of effects on the human brain, and the body of research seems to indicate that a lack of the stuff is a very bad thing.
But there are ways of naturally increasing your levels of BDNF without taking it exogenously, and the next article in this series will explore how.