The EPA and DHA content of red blood cell membranes, expressed as a percentage of total fatty acids. Because red cells turn over slowly, the index reflects omega-3 status across roughly the preceding three to four months rather than what happened at dinner — a real advantage over dietary recall. Those fatty acids incorporate into cell membranes, affecting fluidity, electrical stability and inflammatory eicosanoid production.
Harris WS, von Schacky C. “The Omega-3 Index: a new risk factor for death from coronary heart disease?” Preventive Medicine 2004;39:212–220 proposed the index and found that an index ≤4% carried substantially higher coronary heart disease death risk than ≥8%. Subsequent cohort data are broadly supportive. Outcome-trial evidence for supplementing specifically to raise the index is mixed: VITAL, using low-dose marine omega-3 in a general population, was neutral for major cardiovascular events, while REDUCE-IT, using high-dose purified EPA in higher-risk patients, showed benefit. A reasonable status marker — but “test and target a number” has not itself been proven in a trial to change outcomes for an average-risk person.
Harris WS, von Schacky C. Prev Med. 2004. PubMed: PMID 15208005
Singapore guidance
Not covered in the current review
Singapore’s national screening committee has not reviewed this test in the current volume of its report, which covers nine conditions. That is not a verdict either way.
Source: Screening Test Review Committee report 2026, Volume 1 (Academy of Medicine Singapore and Ministry of Health, February 2026). The full national list · How this is used.
What you would actually pay
- Healthier SG
- Not subsidised
- MediSave
- Not among the screenings named for outpatient claims
Source: Healthier SG Screening (HealthHub) and MediSave outpatient care (Ministry of Health). Absence from either list is not a statement that the test is discouraged — only that no subsidy or claim applies. Gross prices compared.
What it costs when it is wrong
- Basis
- No published harm criterion found
- Severity
- Not documented
Not covered in the current volume of the committee’s report, so no harm criterion was found either way.
An empty finding, not a clean bill of health: this means nothing documented was found for this test. It is not a claim that the test is safe.
Screening harm is not only a laboratory question: the committee’s own criteria advise against a test when “the screening test, or follow-up tests arising from a positive screen, are associated with significant medical risks”. Sources on overdiagnosis → · How this is graded.
FAQ
Is the Omega-3 Index worth doing in Singapore?
Omega-3 Index holds a moderate evidence grade under our screening rubric. It typically costs S$90–140 in Singapore. The usual schedule: one-off or occasional check. Most appropriate for anyone uncertain about their oily fish/supplement intake — not a routine annual test.
Weighing this against something else? Compare it with two other tests → · Price it inside a panel →