EPA and DHA: two molecules, three claims, one dose
Not all omega-3s are equal. What may be claimed depends on the molecule AND the daily dose — 250 mg, a threshold many products miss.
Three molecules routinely confused
The word “omega-3” hides three distinct fatty acids. ALA (alpha-linolenic acid) comes from plants: flax, rapeseed, walnuts. EPA and DHA come from marine products and certain microalgae.
The body converts some ALA into EPA, then into DHA — but the yield is poor, on the order of a few percent, and falls further for DHA. A spoonful of flaxseed oil therefore does not equal a fish-oil capsule.
The distinction is not theoretical: the EU register does not treat these molecules alike.
What each molecule authorises
DHA holds two claims of its own, reproduced below. The EPA + DHA combination holds a third, on heart function.
The practical consequence is sharp: a product rich in EPA but poor in DHA cannot claim brain function or vision. Read the split, not the total.
Authorised claims — register wording
- « DHA contributes to the maintenance of normal brain function. »
- DHA · 250 mg de DHA par jour.
- « DHA contributes to the maintenance of normal vision. »
- DHA · 250 mg de DHA par jour.
- « EPA and DHA contribute to the normal function of the heart. »
- EPA + DHA · 250 mg d’EPA + DHA par jour.
The dosage trap
The condition of use is unusually clear here: 250 mg a day. That figure applies to the amount of EPA and DHA, not to the amount of oil.
Yet labels usually foreground the capsule weight. A “1,000 mg fish oil” capsule typically contains 180 mg EPA and 120 mg DHA — 300 mg in total, which clears the threshold for the heart claim but not the 250 mg of DHA needed for the brain claim.
Two products advertising “1,000 mg” can therefore unlock different claims. The only table that matters is EPA and DHA content per daily portion.
| Claim | Molecule | Required daily dose |
|---|---|---|
| Normal brain function | DHA alone | 250 mg DHA |
| Normal vision | DHA alone | 250 mg DHA |
| Normal heart function | EPA + DHA | 250 mg total |
Note · The claims concern the maintenance of normal functions. None concerns preventing cardiovascular disease — that would be a risk-reduction claim, subject to a separate procedure.
Oxidation: the invisible criterion
Polyunsaturated fatty acids oxidise. An oxidised oil loses its point and takes on a characteristic taste, often masked by added flavourings.
No claim covers this, and no labelling rule requires publishing a peroxide value. It is therefore something a consumer cannot arbitrate alone — only a supplier transparent about its analyses allows a judgement, and that is a question to ask rather than a mention to look for.
Frequently asked
Do vegan omega-3s exist?
Yes: microalgae oils supply DHA directly, sometimes EPA, without going through fish. The same claims apply, at the same doses. Flax or rapeseed oils supply only ALA and do not unlock these claims.
How long until an effect?
The claims concern the maintenance of normal functions with regular daily intake. None is framed in terms of a delay or a perceptible improvement.
Should they be taken with food?
They are lipids: absorption is better with a meal containing fat. No European condition requires it, but it is sound usage advice.
The products concerned
Sources
Only regulatory texts and public registers, checkable by anyone. No bibliographic reference is cited without verification: on a health topic, a false source costs more than none.
- Règlement (UE) n° 432/2012
Establishes the list of permitted claims other than disease-risk-reduction ones, with their conditions of use.
- Commission européenne — EU Register of nutrition and health claims
Searchable database of every authorised and rejected claim. The reference that lets anyone check, word for word, what a product may state.
- Règlement (CE) n° 1924/2006
Sets the framework: a health claim is lawful only if authorised. Bans any claim to prevent or treat a disease.
Our method
No health claim is written by us: every such sentence is taken word for word from the EU register. An active with no authorised claim is presented with none — never with a softened wording.
Food supplements are not a substitute for a varied, balanced diet or a healthy lifestyle. This page is informational and is not medical advice. If you are on medication, pregnant or breastfeeding, seek advice from a healthcare professional.
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