← All episodes Episode 27 · Sleep, Recovery & the Body

What You Eat Literally Builds Your Brain

Neuro-Nutrition: Fats

Foggy brain isn't always about sleep or sugar. Sometimes it's the fat you're not eating.

The Science

Bazinet & Layé (Nature Reviews Neuroscience, 2014): the human brain is ~60% fat by dry weight, with long-chain omega-3 polyunsaturated fatty acids (EPA and DHA) forming critical components of neural cell membranes and myelin.
Bourre (J. Nutrition, Health & Aging, 2004): omega-3 deficiency reduces myelin integrity, slowing axonal signal conduction. The result is detectable cognitive slowing.
Su et al. (JAMA Network Open, 2018): meta-analysis of 19 RCTs (n=2,240) found EPA-predominant supplementation significantly reduced anxiety symptoms, the effect size scaled with dose.

Target 1–3 g of EPA per day.
Best sources: fatty fish (salmon, sardines, mackerel), aim for 2+ servings/week.
Alternative: high-quality fish oil supplement (check the EPA dose on the label, not just "fish oil mg").
Walnuts, chia, flax give you the precursor (ALA), useful but you need more grams.
Be patient: incorporation into neural membranes takes ~2–3 weeks of consistency.

Right-click → Save As to download. Or scan the QR code in the corner to come back here from print.

Bazinet, R. P., & Layé, S. (2014). "Polyunsaturated fatty acids and their metabolites in brain function and disease." Nature Reviews Neuroscience, 15(12): 771-785.
Bourre, J. M. (2004). "Roles of unsaturated fatty acids (especially omega-3 fatty acids) in the brain at various ages and during ageing." Journal of Nutrition, Health & Aging, 8(3): 163-174.
Su, K. P., Tseng, P. T., Lin, P. Y., et al. (2018). "Association of use of omega-3 polyunsaturated fatty acids with changes in severity of anxiety symptoms: A systematic review and meta-analysis." JAMA Network Open, 1(5): e182327.

Educational content only. Not medical advice.

Also on Instagram: @neurosensebrain