The Oasis Health Journal · Submitted September 28, 2026 · 3:02 PM EDT
By June Mackerel · Edited by Colette Ward
Listen · June Mackerel reads this piece · 2:10
The erucic acid supplement industry has built an entire wellness narrative on studies published before Madonna's first divorce, and nobody has felt the need to update the premise in the intervening decades, which one imagines has been terribly convenient for everyone involved.
Erucic acid is a very long chain fatty acid, 22 carbons in length, found primarily in rapeseed oil and mustard seed. It is also available in capsule form, often marketed with the phrase "myelin support" or "nervous system health", which are technically phrases and not medical claims, a distinction the label writers have circled in red pen with enormous pride.
The marketing implies rather a lot. The published research supports considerably less. And the gap between the two has not narrowed in fifteen years, which one would think might trouble somebody, somewhere.
The Adrenoleukodystrophy Connection Nobody Mentions Properly
The original scientific interest in erucic acid came from research on X-linked adrenoleukodystrophy, a devastating genetic disorder caused by mutations in the ABCD1 gene. In that condition, very long chain fatty acids accumulate incorrectly, leading to severe neurological decline and adrenal insufficiency. A 2024 review in Lipids in Health and Disease described the condition in some detail, emphasising that its pathophysiology remains incompletely understood and that effective treatments remain elusive, which is medical journal language for "we are still rather stuck."
In the 1980s, a dietary intervention called Lorenzo's Oil was developed. It was a mixture of oleic acid and erucic acid, administered under strict medical supervision to patients with the genetic disorder. The results were mixed, the protocol was extraordinarily difficult to follow, the oil tasted ghastly, and subsequent advances in gene therapy have rather overtaken it as a treatment avenue.
The supplement industry appears to have looked at that history and concluded that if erucic acid might help in a severe genetic condition involving myelin breakdown, it must logically support general nervous system wellness in healthy adults who play Wordle every morning. This reasoning has a certain appeal if one does not think about it too carefully, or indeed at all.
What the Recent Research Actually Measured
A 2025 study in Nutrients analysed the fatty acid content of colostrum from seventy-eight healthy mothers who delivered term babies. The researchers measured twenty-two different fatty acids and looked for correlations with birth weight and thyroid hormone levels. Erucic acid was one of five fatty acids that correlated positively with birth weight across the entire cohort, and the correlation remained significant in the subset of mothers with high TSH values.
The study did not measure nervous system outcomes. It did not administer erucic acid to anyone. It observed a correlation in naturally occurring colostrum, noted that the regulatory mechanisms might overlap with fetal fat accretion, and suggested that colostrum content might adjust to compensate for subtle thyroid deficiencies. These are reasonable observations about breast milk chemistry.
They are not evidence that swallowing a capsule does anything to one's myelin.
A 2025 review in Frontiers in Nutrition made the case for nervonic acid fortification in infant formula. Nervonic acid is another very long chain fatty acid, 24 carbons in length, which the body can synthesise from erucic acid through a series of elongation steps. The review noted that nervonic acid plays a role in brain development and myelin biosynthesis, that it is present in minute amounts in human milk, and that premature infants might benefit from higher dietary intake.
The review also noted that there is currently no ingredient available for fortification, though recent advances in biotechnology have made it feasible to produce high-nervonic-acid oil through fermentation. A 2023 paper in Communications Biology reported that engineered yeast achieved a nervonic acid titer of 17.3 grams per litre, the highest reported to date, with a purity of 98.7 percent after purification. One imagines the yeast were not consulted about their feelings on this.
The commercial interest in infant formula fortification is considerable. The evidence that an erucic acid supplement does anything measurable in a healthy adult human nervous system is not.
The colostrum study was observational. The infant nutrition review was forward-looking. The yeast fermentation paper was about industrial production efficiency and did not involve a single human brain.
The Biomarker Problem
The difficulty with evaluating nervous system health claims is that myelin is rather difficult to measure non-invasively. Early studies relied on clinical outcomes in patients with severe disease. Modern research has access to advanced imaging, blood biomarkers, and metabolomic profiling, none of which have been applied to erucic acid supplementation in healthy populations, a gap one might describe as "the entire point."
A 2024 review in the International Journal of Molecular Sciences discussed the role of lipid supplementation in central nervous system regeneration, noting that nervonic acid synthesis substrates could be beneficial in remyelination. The review pointed to the need for further studies and suggested that properly profiled lipid supply might serve as supportive therapy during CNS regeneration.
It did not specify what "properly profiled" means in practical terms. It did not identify an optimal dose. It did not cite a human trial in which anyone measured remyelination after taking an erucic acid supplement. One notes that these are rather important details, the sort of thing one might want to establish before printing a label that says "supports myelin health."
The supplement labels, meanwhile, continue to feature phrases like "supports myelin health" and "promotes nervous system function", which are not medical claims and therefore do not require evidence, a regulatory loophole large enough to drive a lorry through while texting.
The Studies That Have Not Been Done
What would a modern trial look like? One imagines it would involve healthy adults, a placebo control, a defined dose of erucic acid, and a measurable outcome: cognitive testing, imaging, serum biomarkers, something quantifiable that is not merely "I feel sharper." It would run for at least twelve weeks, ideally longer, and it would be powered adequately to detect a clinically meaningful effect, assuming there is one to detect.
No such trial appears in the recent literature.
A 2024 paper in Frontiers in Microbiology demonstrated that Lactobacillus johnsonii can metabolise erucic acid and incorporate it into its own fatty acid profile, synthesising nervonic acid and other omega-9 fatty acids in the process. This is interesting from a microbial metabolism perspective, and absolutely delightful for the bacteria involved. It does not tell us whether eating erucic acid changes human myelin composition, cognitive function, or anything a person would notice unless they are unusually attuned to their gut bacteria's lipid preferences.
The industry has evidently decided that the evidence from the 1980s and 1990s is sufficient, and that further inquiry would be unnecessarily expensive and possibly inconvenient.
What Remains
Erucic acid is a real molecule. It is a precursor to nervonic acid. Nervonic acid is a component of myelin. None of that is in dispute, and all of it is on the label, right next to a price tag that suggests someone is terribly confident about something.
What is in dispute, or rather what has never been established, is whether consuming erucic acid in supplement form produces any detectable benefit in a person whose nervous system is functioning normally to begin with.
The pre-2010 studies were conducted in patients with severe genetic disorders, under medical supervision, with outcomes measured in terms of disease progression. The recent studies involve colostrum composition, yeast fermentation, and bacterial metabolism. The gap between those two bodies of work is the part where someone would normally conduct a human trial and measure something that matters.
That trial has not happened.
One imagines there is a reason for that, and the reason is probably not that the supplement industry has been too frightfully busy to get around to it.
This article is education and reporting on published research. It is not medical advice, and nothing here is intended to diagnose, treat, cure or prevent any disease. Talk to your own clinician about your own situation.
Sources
- ω9 Monounsaturated and Saturated Colostrum Fatty Acids May Benefit Newborns in General and Subtle Hypothyroid Stages, Nutrients (2025).
- Nervonic acid in infant nutrition: a forward-looking approach to enhancing neurodevelopmental outcomes, Frontiers in nutrition (2025).
- From gene to therapy: a review of deciphering the role of ABCD1 in combating X-Linked adrenoleukodystrophy, Lipids in health and disease (2024).
- Nervonic Acid Synthesis Substrates as Essential Components in Profiled Lipid Supplementation for More Effective Central Nervous System Regeneration, International journal of molecular sciences (2024).
- Erucic acid utilization by Lactobacillus johnsonii N6.2, Frontiers in microbiology (2024).
- High-level production of nervonic acid in the oleaginous yeast Yarrowia lipolytica by systematic metabolic engineering, Communications biology (2023).
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