Claire Taubert
In discussions about brain function, the grey matter of the brain is often referenced.
In fact grey matter is the outer layer of the brain structure.
We don’t hear much about the white matter, located internally under the grey matter. The grey matter is composed of neuronal cell bodies designed for processing and interpretation, while the white matter is comprised of nerve fibres ( axons) designed for transmission of information signals around the brain.
The white matter of our brains located in the cortex ,consists of bundles of nerve fibres coated in myelin ,a fatty substance the assists electrical signals travel quickly and efficiently. This creates an internal wiring system connecting different regions of the brain so they can work together processing and retrieving information effectively. It is the largest part of the brain .
As we age there are subtle changes which can occur in the brain ,these changes are associated with a slower processing speed and reduced co ordination between different brain regions. This slowing down can be experienced as the very common experience of thwarted intentionality to use a word but being unable to ”find” the word or walking purposefully into a room discovering you don’t recall why or what you were intending to locate in that room…. many other small but frustrating cognitive bleeps can be experienced as we age.
There is encouraging research about how lifestyle habits can influence how well the white matter is maintained. This emerging research suggests that moderate calorie restriction, a reduction of total calory intake without comprising nutrition may assist in protecting vital brain structure including white matter. This effect appears to be linked to reduced inflammation, improved metabolic function and enhanced cellular repair.
In animal studies calorie restriction has been shown to preserve white matter microstructure and reduce age-related degeneration. A study examining older adults found that a lower caloric intake was associated with better memory performance and markers of improved brain function. While more direct human research studies on white matter are ongoing the biological mechanisms suggest a strong protective effect.
How does calorie restriction support brain structure?
When you eat slightly less there is a reduction of oxidative stress. Oxidative stress is an imbalance between free radicals (unstable molecules) and antioxidants in the body. An excess of radicals causes damage to cell structures, proteins and DNA… contributing to aging and chronic disease , none of which is good for tissue health in particular white matter.
Another important factor is inflammation. Chronic low grade inflammation has been linked to white matter decline. Calorie restriction has been shown to lower inflammatory markers, creating a more supportive environment for brain cells.
With lower inflammation there is also an increase in autophagy which is our brain’s natural “clean up” process where damaged cellular components are removed.
This process of cellular cleanup is vital for maintaining neuronal integrity and supporting myelin repair.
Myelin plays a vital role in your brain’s communication network ie white matter. Myelin is made up of largely lipids and proteins, its maintenance requires an efficient cellular process hence autophagy. Studies suggest that calorie restriction can promote the survival and function of oligodendrocytes which are the cells responsible for producing myelin.
In research models dietary restriction has been linked to improved myelin preservation and reduced age related deterioration. This suggests that eating in a way the supports metabolic health may indirectly help maintain the brain’s white matter and other communicative pathways.
For some years now there has been commentary about intermittent fasting which is really just another way of reducing calories without the angst of constant restriction.
This approach involves cycling through periods of eating and fasting. Anthropological studies suggest that this was the normal manner of eating for early humans.
It allows the body time to repair and reset. Intermittent fasting activates many of the same pathways as calorie restriction.
Research has shown that fasting can enhance synaptic plasticity, improve mitochondrial function and support white matter integrity.
But it is not just about eating less…. it is about eating well .
The quality of what you eat matters just as much as quantity. Nutrient dense foods provide the building blocks your brain needs to maintain white matter. Healthy fats particularly omega -3 fatty acids , support myelin structure. Antioxidants from fruits and vegetables help protect against oxidative damage. Remembering to eat a “rainbow “diet ,that is food of different natural colours not just “white” foods which are often highly processed foods, low in nutrient value and high in calories.
This combination of moderation and nourishment appears to be the key for long term white matter health. It is very important to emphasis that more is not always better when it comes to eating less. Extreme calorie restriction can be harmful and lead to nutrient deficiencies and or reduce energy levels.
Small changes like mindful portion sizes, spacing meals appropriately, or reducing snacking can activate many of the beneficial pathways associated with calorie restriction without being too restrictive.
It is a matter of a balanced approach for long term healthy aging and the maintenance of white matter health which in term supports both physical and cognitive vitality.
Claire Taubert is a Psychologist & Psychotherapist at Gestalt Concepts.
Co-Founder of Gestalt Therapy Australia
Image sourced from: health.harvard.edu
