Did you know that by age two, a baby’s brain is already 60% of it’s adult size?
I’m going to focus in on just one aspect found in this research: Brain Myelination. That is the process by which a fatty, insulating layer called myelin forms around the axons of neurons in the central and peripheral nervous systems. You’ll discover why this process is so critical to your child’s early development, and most importantly how it will ultimately determine their future mental and physical health.
Supporting myelination through a diet rich in essential fatty acids, choline, iron, and adequate thyroid function is especially important during infancy and early childhood, when the brain is most plastic, rapidly growing and vulnerable to nutritional deficiencies and toxins. But it’s not just for those formative years. It’s ongoing for life.
When you understand how rapidly the infant brain is being built, and understand just a few things about what it takes to quickly build a healthy, elastic, and resilient baby’s brain, perhaps you will also understand why we are seeing an epidemic of serious developmental and behavioural disorders among children today.
The sources for this article (listed at the end) collectively support the nutritional benefits of eggs, meat, saturated fats, and bone‑derived nutrients for infants, as well as their roles in bone, muscle, brain, hormonal development, overall metabolic health and in reducing insulin resistance, and moderating inflammation.
This myelin sheath is produced by specialized glial cells—oligodendrocytes in the brain and spinal cord, and Schwann cells in peripheral nerves. Myelin dramatically speeds up electrical signal conduction, protects axons, and supports neuronal health.
Why Myelin Matters
Function: How Myelin Contributes to Rapid Signal Transmission
Myelin enables saltatory conduction: electrical impulses jump from one node of Ranvier (gaps in the sheath) to the next, increasing speed up to 100‑fold compared with unmyelinated fibers.
Energy Efficiency: Faster conduction reduces the metabolic cost of maintaining ion gradients, conserving glucose and oxygen for other brain processes.
Axonal Protection: The sheath shields axons from mechanical stress and toxic substances, helping preserve structural integrity.
Neural Plasticity: Myelin remodeling will continue throughout life, but optimal construction and renewal requires optimal nutrition allowing for fine‑tuning of neural circuits during learning, skill acquisition, and recovery from injury.
Timeline of Myelination in Humans
Developmental Stage – Major Myelination Events:
Prenatal (mid‑gestation) Initiation of oligodendrocyte precursor cells (OPCs) in the spinal cord and brainstem.
Birth to 6 months Rapid myelination of sensory pathways (e.g., visual and auditory tracts).
6 months – 2 years Myelination spreads to motor cortex, basal ganglia, and cerebellum—critical for gross motor milestones (crawling, walking).
2 years – 5 years Language‑related regions (Broca’s and Wernicke’s areas) become increasingly myelinated, supporting speech development.
5 years – adolescence Ongoing myelination of association cortices (prefrontal, parietal), linked to executive functions, attention, and abstract reasoning.
Adulthood
Myelin continues to remodel in response to experience, though the rate slows; degradation or demyelination underlies many neurodegenerative diseases (e.g., multiple sclerosis) and as we now know, inappropriate diet, the so-called Standard American Diet is accelerating this degeneration.
Biological Drivers of Myelination
Genetic Programs – Transcription factors such as OLIG2, SOX10, and MYRF guide OPC proliferation, migration, and differentiation into mature oligodendrocytes.
Neuronal Activity – Electrical firing stimulates release of neurotransmitters (glutamate, ATP) that act on OPCs, promoting myelin formation where it is most needed.
Nutritional Factors
Essential fatty acids (especially DHA, an omega‑3 LC‑PUFA) are incorporated into myelin phospholipids.
Choline and phosphatidylcholine supply the building blocks for the myelin membrane.
Iron is a cofactor for enzymes involved in lipid synthesis; deficiency impairs oligodendrocyte function.
Hormonal Influences – Thyroid hormone (T₃) and insulin‑like growth factor‑1 (IGF‑1) enhance oligodendrocyte maturation.
Clinical Relevance
Developmental Disorders: Delayed or abnormal myelination is observed in autism spectrum disorder, cerebral palsy, and certain language delays. Early neuroimaging (MRI diffusion tensor imaging) can detect these patterns.
Nutritional Interventions: Adequate intake of DHA, choline, iron, and vitamin B12 during pregnancy and infancy supports optimal myelination.
Neurodegeneration: Demyelinating diseases (multiple sclerosis, leukodystrophies) involve loss or dysfunction of myelin, leading to slowed conduction, sensory deficits, and cognitive decline.
Recovery & Plasticity: Post‑injury remyelination can be stimulated by activity‑based therapies, pharmacologic agents (e.g., clemastine), and dietary strategies that supply myelin precursors.
The Bottom Line
Brain myelination is a foundational developmental process that equips neurons with fast, efficient communication pathways. It unfolds over a prolonged timeline—from mid‑gestation through early adulthood—and is shaped by genetics, neuronal activity, hormones, and nutrition.
Supporting myelination through a diet rich in essential fatty acids, choline, iron, and adequate thyroid function is especially important during infancy and early childhood, when the brain is most plastic, rapidly growing and vulnerable to nutritional deficiencies and toxins. A diet of animal based proteins and fats found in eggs, meat, saturated fats, butter, bone, and bone broths provides an optimal bio-available source of those nutrients and minerals essential for the healthy early development and life long maintenance of the human brain.