Maintaining a Healthy Nervous System
Your brain is at the core of your identity. Your nervous system is an extension of your brain; it works in concert with the brain to sense the outside world and allow you to function as a human being. Your brain and nervous system are effectively you. No matter what else you do to maintain health and stay more youthful, it doesn’t amount to very much if you don’t have a brain to appreciate your new healthy life.
The relationship between brain functions and what we think of as “the mind” has been a topic of philosophical and psychological research for generations, probably since humans started to be aware that they were humans. For the purposes of this book, I won’t get into that. All we need to focus on, for the purposes of Age Later, is the idea that the health and performance of our body, skin, mind and brain are all intertwined. Looking after one component helps the others.
A Plan to Move Your Brain Up a Notch
The basic anatomy might be the same, but your brain is uniquely yours. So make the effort to draw up an action plan for brain health that’s unique to you. Everything you decide to include in your mental fitness regimen should be a personal pleasure for you.
Earlier in this chapter, I provided suggestions for mindfulness, stress reduction and sleep. All of these contribute to the physical health of your brain at the same time as they build psychological strength and stability.
In earlier chapters of the book, I outlined healthy living choices for food and physical exercise. Following these choices will contribute to the health of your nervous system, just as they will improve skin and body health.
But there’s even more you can do—and should do—to boost your brain’s performance and extend its life. You can find ways to exercise your mental muscles that also result in measurable improvements to your brain cells.
Just living in a complex world exercises the mind. But sometimes things can get so complex that people’s brains start to shut down instead of functioning at maximum capacity. In this section, I offer suggestions that will help you cope with that complexity, help prevent shut-downs, and also boost the long-term health of the brain.
The Workings of the Human Nervous System
We now know enough about the workings of the brain and the central nervous system to be confident that the onset of illnesses such as Alzheimer’s and Parkinson’s can be prevented or delayed if action is taken early enough.
So, let’s do a deeper dive into those workings.
We tend to think of our brain as the control center of the body because that’s where most of the conscious thought takes place, including how you’re processing the information in this book. The brain is connected to the entire nervous system, which is spread throughout the body, and control of the body is distributed throughout that entire system. This vast network consists of your brain, the nerves in your spinal column, peripheral nerves everywhere else in your body, and your sensory system, which detects what’s going on in the outside world and inside your body.
The body contains, and depends on, a complicated communications system, much like the internet—except smarter and more reliable. Communication between neurons physically happens through the combination of a variety of chemical and electrical signaling. Neurons play an important part in building the communications infrastructure, connecting to the brain, to muscles, the sensory organs, and to the other organs of the body. In addition, various endocrine glands (pineal, thyroid, adrenal and so on) signal their wishes by injecting chemicals into the bloodstream. In this way, our blood conveys chemical messages throughout the body, another part of the communications complex.
Using this network, the body can sense its own status and behavior, a process called interoception.
The external world provides its input through the sensing processes that allow us to experience the world: perception. Our perceptive senses enable us to see, hear, feel, taste and smell. Neurons capture this information this using tree-like extensions called dendrites that are connected to the mechanical and chemical sensors in the skin, eyes, ears, mouth and eyes. The collecteddata allows us to understand and navigate the world around us.
The nervous system constantly sends signals to motor neurons that trigger muscles to contract or relax. Other neurons (interneurons) act as relays to pass information throughout the nervous system to yet other neurons, sometimes to hundreds all at the same time.
All neurons are connected to other neurons and pass information to each other using chemical and electrical signals via axions (transmitter paths), dendrites (receptors) and synapses (axion to dendrite interfaces). Within the brain and throughout the entire nervous system, patterns of neuron connectivity influence how we respond to stimuli and what we remember. As we acquire knowledge, the patterns of neural connectivity are constantly being modified and updated. Neuron patterns reflect who we are and what we know.
Neurons are plentiful in our bodies. A typical healthy human nervous system contains around 100 billion neurons of many different types.[1]
Neurons are not the only vital components in our nervous system. We also need to consider glial cells (or glia). Estimates vary, but it seems likely that there are at least as many glial cells than neurons in most human brains.[2]Not only are glial cells plentiful, experiments have shown that many brain functions depend not just on neurons, but on glia.[3]
Glia play a role in performing such housekeeping functions as managing the delivery of nutrients to other nervous system cells, cleaning up dead cells, building and maintaining the protective sheathing around axons, managing the creation of synaptic connections between neurons, and closing down neural pathways that seem to be redundant or unnecessary. Once again, if you don’t use it, you do lose it.
Glia ensure the blood and oxygen supply to the brain is maintained.[4]Glia communicate with each other—and with neurons. They also eavesdrop on signals between neurons. The purpose of all this interaction is not entirely understood, but it seems clear that glia play some role in human brain functioning (and therefore cognition). Perhaps they contribute to logic, to creativity and to decision making.[5]
Glia and neurons are widespread through the body, in the central nervous system and in the peripheral nervous system. So as we think about brain health, we really need to think about the health of the entire nervous system, which reaches almost everywhere in our bodies.
What Can Go Wrong?
There are many ways in which the nervous system can become degraded: cells die; glial cells prune pathways but may make mistakes; axon sheathing may deteriorate faster than it can be renewed. Your nervous system is yet another collection of cells, so the entire nervous system can suffer from oxidation and inflammation, just like all the other cells in the body.
Feelings of stress and anxiety cause your nervous system to respond aggressively by producing adrenalin. If prolonged, severe stress can affect brain functioning which can result in impaired concentration and reduced control of impulses.[6]Managing stress is an essential part of maintaining a healthy brain.
Damage to (or deterioration of) the nervous system can cause a wide range of problems, including slow reflexes, forgetfulness and confusion. These problems may be temporary, or sometimes they may be early symptoms of dementia, a broad label for a range of neurological diseases. Dementia is characterized by some or all of the following symptoms: severe memory loss, impaired reasoning, language difficulties, inability to focus and even personality changes. Dementia may be caused by cardiovascular disease, thyroid problems, trauma, vitamin deficiencies or one of a number of diseases involving abnormal protein cells in the brain—specifically, Lewy Bodies disease (LBD), Parkinson’s disease, and Alzheimer’s disease.
Actions You Can Take
Although symptoms of neurological diseases can sometimes be alleviated, once many of these diseases have taken hold, there is no cure. Still, some lifestyle changes can improve cognition and help delay (or even avoid) these diseases.
For example, a two-year trial in Finland (2014)[7]revealed that changes to diet and exercise resulted in measurable improvement in cognition. It is also suggested that ongoing mental activity and social activity can play a part in maintaining the nervous system and avoiding deterioration. Many other studies confirm these findings. As a result, the Alzheimer’s Association concurs with the notion that combatting cognitive decline requires a multifaceted and holistic approach.[8]
Research into nervous system health has identified a few key factors that together may delay, stop, or even reverse, a decline in nervous system functioning. These include: active thinking and cognitive exercise, social interactions, stress reduction, physical exercise and nourishment.
[1]. How Many Neurons do we have? https://www.ncbi.nlm.nih.gov/pubmed/27187682. Also: The search for true numbers of neurons and glial cells in the human brain: A review of 150 years of cell counting. von Bartheld CS1, Bahney J2, Herculano-Houzel S3.
[2].https://blogs.scientificamerican.com/brainwaves/know-your-neurons-what-is-the-ratio-of-glia-to-neurons-in-the-brain/
[3].https://blogs.scientificamerican.com/brainwaves/know-your-neurons-meet-the-glia/
[4]. Glia: https://www.scientificamerican.com/article/without-glia-brain-would-starve/
[5]. Glial cells. A thought-provoking article is at: https://www.scientificamerican.com/article/the-root-of-thought-what/
[6]. The effects of stress exposure on prefrontal cortex: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4244027/
[7]. A two-year multidomain intervention of diet, exercise, cognitive training, and vascular risk monitoring versus control to prevent cognitive decline in at-risk elderly people (FINGER): a randomised controlled trial. Tia Ngandu and others in Lancet Neurology, Vol 15, No. 5. April 2016.
[8]. “Experts agree that in the vast majority of cases, Alzheimer’s, like other common chronic conditions, probably develops as a result of complex interactions among multiple factors, including age, genetics, environment, lifestyle, and coexisting medical conditions.” (http:/www.alz.org)
Dr. Marc Ronert - Age Later 