If you take omega-3, you are probably doing it for a reason. The problem is that taking something tells you about the input, not the outcome. An omega-3 test is a way to check the outcome.
What gets measured
Most at-home tests use a dried blood spot: a few drops from a fingertip on a filter card.[source pending] The lab measures the fatty acids in the sample and reports values such as:
- The omega-6:3 balance, which reflects the overall balance of fats in your diet.
- The Omega-3 Index, EPA and DHA as a share of the fatty acids in your red blood cells.[source pending]
- A wider fatty-acid profile, compared with reference values.
Why the result reflects months, not days
Red blood cells are replaced gradually over roughly four months.[source pending] So the result says more about your habits over the past season than about last week. It also means a retest needs time.
What the test can’t do
It doesn’t diagnose anything. It can’t tell you what caused your result, and it can’t on its own tell you exactly what to do. Researchers also debate how much weight to put on the ratio by itself.[source pending] Read what a test can and can’t tell you for the full picture.
When testing makes sense
- You already take a supplement and want to know whether your intake adds up.
- You are about to change your diet and want a baseline to compare against.
- You like to make decisions based on your own numbers.
What the EU allows us to say about EPA and DHA
EPA and DHA contribute to the normal function of the heart (with a daily intake of 250 mg of EPA and DHA). DHA contributes to the maintenance of normal brain function and normal vision (with a daily intake of 250 mg of DHA).[European Commission 2012]
Next step
Not sure where you stand? Take the free 2-minute check. It asks about habits, not health.
Sources
- [source pending] Source needed: validation of dried blood spot fatty-acid analysis against venous samples
- [source pending] Source needed: original definition of the Omega-3 Index (EPA + DHA as % of red blood cell fatty acids)
- [source pending] Source needed: red blood cell lifespan (~120 days) and how fast membrane fatty acids change
- [source pending] Source needed: review discussing the usefulness and limits of the omega-6:3 ratio as a marker
- European Commission. Commission Regulation (EU) No 432/2012 establishing a list of permitted health claims made on foods, other than those referring to the reduction of disease risk and to children’s development and health. Official Journal of the European Union (2012).