What Your Baby Is Made Of

Your baby is under construction.

Not growing. Not developing. Building.

Every neuron needs a membrane. Every axon needs myelin. Every mitochondrion needs an inner membrane with precisely curved cristae. Every tendon needs collagen. Every artery needs elastin.

Where do the materials come from? The food.

The Deep Fryer Revelation

Think of a deep fryer that has been running for too long. The oil becomes thick, dark, and sticky. The same chemical processes that ruin cooking oil—oxidation, crosslinking, the formation of rigid molecular structures—operate in biological tissues throughout life.

Here is the twist: the same chemistry operates during development. Just in reverse.

During aging, good structure becomes damaged structure. During development, raw materials become assembled structure. Same reactive chemistry. Different direction.

The question is whether you are providing building materials that survive this chemistry intact, or building materials that arrive pre-damaged.

What Is Actually Being Built

Consider what your infant is constructing in those first eighteen months:

The brain's insulation. Myelin wraps nerve fibers, enabling fast electrical signaling. It is made primarily of cholesterol—roughly 40% by mass—along with saturated fats. The brain triples in size between birth and age three, with myelination peaking during this window.

The cell's power plants. Mitochondria produce approximately 90% of cellular energy. The key lipid is cardiolipin, which matures primarily in the first weeks after birth. The efficiency established during this window persists for life.

The body's scaffolding. Elastin provides flexibility and resilience. The critical fact: elastin is synthesized only during development. Your body cannot make new elastin after childhood. What gets assembled is all you get.

Good Materials Versus Bad Materials

Low-distortion building blocks include:
• Saturated fats (stable and resist fragmentation)
• Cholesterol (essential for myelin and membranes)
• DHA and arachidonic acid (specialized structural lipids)
• Glycine and proline (backbone of collagen)

High-distortion building blocks include:
• Oxidized seed oils (arrive already damaged)
• Excessive linoleic acid (oxidizes easily)
• Advanced glycation end-products from processed foods
• Trans fats (wrong geometry but incorporated anyway)

Three Vulnerable Windows

Window one: the brain. From birth to roughly 36 months, the brain triples in size, myelination peaks, and DHA accumulates rapidly. This window mostly closes by age three.

Window two: the mitochondria. In the first weeks after birth, cardiolipin composition undergoes critical remodeling. The efficiency established now determines energy production capacity for life.

Window three: the extracellular matrix. From fetal development through childhood, elastin synthesis occurs. Because elastin production stops after childhood, any damage during synthesis means permanent functional loss.

What Traditional Cultures Knew

Every traditional culture obsessed over maternal and infant nutrition with specific food recommendations that recur across geographic and historical boundaries:

Egg yolk appears in first-food recommendations across diverse cultures

Liver shows up everywhere as a recommended food for mothers and young children

Bone broth for new mothers is traditional across Asia and elsewhere

Fish heads in African traditions, cod liver oil in Scandinavia, organ meats across Asia

These cultures did not know about cardiolipin or myelin or cristae geometry. But they noticed that babies fed these foods thrived. The recommendations persisted because they produced results.

We now have the mechanism. These foods provide low-distortion building blocks that preserve geometric fidelity during tissue construction.

The Window Closes

Some substrates are synthesized only during development. If you build these structures from damaged materials, you cannot fully rebuild later.

You can optimize maintenance. You can slow subsequent degradation. You can support what was built. You cannot replace elastin that was never properly synthesized.

The materials provided during development set the initial condition. Everything after is trajectory from that point.

This is not fatalism. Adults have enormous agency over their health trajectory. But some agency exists only during the brief window of construction.

Practical Implications

For infants six to eighteen months, priority foods include:
• Egg yolk
• Liver (capped, with safety rules)
• Fatty fish
• Bone broth
• Full-fat dairy, ideally fermented
• Pastured meats

Foods to minimize include:
• Seed oils
• Processed baby foods
• Fried foods
• Refined grains and sugars

Your baby is under construction. The materials matter.