Oleic acid optimal range and reference range
Compiled by Alina Radu, founder of Sera, from the published sources below · Last reviewed November 9, 2026
Sera's bands for Oleic acid:
- Optimal 10 – 20 %; sufficient 8 – 25 %; out of range below 8 or above 25 %.
Evidence grade: Published reference interval. A band that primarily reflects a published adult laboratory or population reference interval. It is not necessarily applicable to every assay or laboratory.
All units
| Unit | Optimal | Sufficient | Out of range |
|---|---|---|---|
| % | 10 – 20 | 8 – 25 | below 8 or above 25 |
What the evidence says
No published reference interval or clinical threshold exists for red cell oleic acid in percent; the bands are Sera's own. They are consistent with cohort averages measured by one method across seven countries: 13.5% to 16.5% in most cohorts and 17.6% to 18.9% in Spanish and Italian ones. The outer edges of 8% and 25% have no source. Not essential — the body synthesises it — so the level reflects endogenous production as much as olive oil, and a high value on a low-fat diet points at active lipogenesis rather than intake. Read beside palmitic acid. Percentages depend on which fatty acids the panel counts, so compare only within one laboratory.
Assay: Results differ meaningfully between platforms and methods. Compare against the interval printed by the issuing laboratory before acting on a borderline value.
Sources
- Red Blood Cell Fatty Acid Patterns from 7 countries: Focus on the Omega-3 Index — Schuchardt JP, Cerrato M, Ceseri M, et al. — Prostaglandins, Leukotrienes and Essential Fatty Acids, 2022 · Peer-reviewed publicationMean red cell levels measured by one laboratory method in 17 cohorts (Italy, Spain, Germany, Canada, United States, Japan, Korea; 167,347 people). Cohort means only: the paper gives no percentiles or reference interval. Oleic acid (C18:1n9) means: 13.5% to 16.5% in most cohorts, 18.9% in Italy and 17.6% in Spain. All lie inside the optimal band of 10 to 20%; no edge is supported.
- Using an erythrocyte fatty acid fingerprint to predict risk of all-cause mortality: the Framingham Offspring Cohort — McBurney MI, Tintle NL, Vasan RS, et al. — The American Journal of Clinical Nutrition, 2021 · Peer-reviewed publicationFramingham Offspring, 2,240 adults, 27 red cell fatty acids as percent of total. Only myristic, palmitoleic, behenic acid and the Omega-3 Index predicted all-cause death; oleic acid did not. Supports the statement that there is no outcome-linked threshold.
What Oleic Acid (C18:1 n-9, RBC) measures
The monounsaturated omega-9 fatty acid that dominates olive oil, and typically the single largest fatty acid in the membrane after palmitic acid.
Not essential — the body makes it — so the level reflects synthesis as much as diet, and a high value on a low-fat diet points at active lipogenesis rather than at olive oil. Read it beside palmitic acid rather than on its own.