The Space Between Reaction and Regulation
Nutrition•No. 05 of 15
Omega‑3s and Neural Structure
The brain is roughly sixty percent fat by dry weight. What kind of fat has been supplied over years shapes the physical structure of the nervous system doing the reading of these words.
What Omega-3s Are Actually Doing
Long-chain omega-3 fatty acids — EPA and DHA — are integrated into neuronal cell membranes. They influence membrane fluidity, receptor function, and inflammatory signalling. Adequate omega-3 status is associated with lower depressive symptoms, better cognitive performance in aging, and reduced systemic inflammation that would otherwise reach the brain.
Where They Come From
The most concentrated sources are fatty fish — salmon, sardines, mackerel, herring, anchovies — eaten two to three times a week. Plant-based ALA sources like flax, chia, and walnuts provide precursors, though conversion to EPA/DHA is limited. Supplemental fish or algae oils are a reasonable second choice when fish is not available.
Why This Matters Slowly
Membrane composition changes over months, not days. Improving omega-3 intake is a slow-acting Navigation Capacity investment. Nothing dramatic happens the first week. Six months in, the substrate is different — and the nervous system on top of it tends to be a little steadier for reasons no single day of eating explains.
“The nervous system reading these words was physically built, in part, from what was eaten years ago.”