Omega-3 (EPA and DHA)
Fish oil, krill, algae: how to count EPA and DHA, why "1000 mg fish oil" is not 1000 mg of omega-3, and how to choose.
- EPA and DHA contribute to the normal function of the heart.
- DHA contributes to maintenance of normal brain function.
- DHA contributes to the maintenance of normal vision.
The beneficial effect is obtained with a daily intake of 250 mg of EPA and DHA; for the brain and vision, 250 mg of DHA a day.
A varied and balanced diet and a healthy lifestyle are important.
What it is
Omega-3s are a family of polyunsaturated fatty acids. Two of them matter in supplements: EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). Their main food source is oily sea fish: salmon, mackerel, herring, sardines. Plant omega-3 (ALA from flax and walnuts) is a different substance.
EPA and DHA have authorised claims in the European Union — they are listed above. The heart claim applies to products giving 250 mg of EPA and DHA a day, the brain and vision claims to 250 mg of DHA a day. We show them only on products whose label reaches that amount.
How to read the label
"Fish oil 1000 mg" is the weight of oil in the capsule, not the omega-3. Ordinary fish oil holds about 300 mg of EPA and DHA together per 1000 mg, concentrates 500–900 mg. Compare the sum of EPA and DHA in the daily dose — it is in the table on the pack.
The triglyceride form (TG, rTG) is closer to what is in fish; ethyl esters (EE) are cheaper to make. Krill oil carries omega-3 in phospholipids, but usually less EPA and DHA per capsule.
How it is taken
Capsules are taken with a meal — they sit better and repeat less. Keep the product cool and closed: fatty acids oxidise. People on blood-thinning medicines should ask a doctor before taking high doses.
How to choose
Work out EPA+DHA per daily dose and the price per 1 g of EPA+DHA — that shows the real cost. For vegans there is algal oil with DHA and EPA. Look for freshness and purity certificates (such as IFOS) and at the format: small capsules are easier, liquid oil is cheaper.
Frequently asked questions
How much EPA and DHA is in a fish oil capsule?
Ordinary fish oil holds about 300 mg of EPA+DHA per 1000 mg of oil, concentrates up to 900 mg. The exact figure is in the composition table on the pack.
Is there vegan omega-3?
Yes, microalgae oil contains DHA and often EPA. Flaxseed oil gives ALA — a different omega-3 acid.
Why does fish oil repeat on me?
Usually because it was taken on an empty stomach or the oil has oxidised. Take capsules with a meal and keep the tub closed and cool.
How can I tell if fish oil is fresh?
A strong unpleasant smell when a capsule is opened is a sign of oxidation. Look for freshness certificates (such as IFOS) and keep it cool.
Cod liver oil or fish oil?
Cod liver oil contains EPA and DHA plus vitamins A and D; count them if you take those vitamins separately.
Can vegetarians take omega-3?
Not fish oil, but algal oil yes. Gelatine capsules may be animal-derived; check the labelling.
Omega-3 & fish oil in the shop
