What it is
Long-chain omega-3s, EPA and DHA, come from oily fish and from algae. They have authorised EU claims, each with its amount: DHA contributes to the maintenance of normal brain function and vision (250 mg a day); EPA and DHA contribute to normal heart function (250 mg a day) and to the maintenance of normal triglyceride levels (2 g a day).
The trap on the label: "1,000 mg of fish oil" is not 1,000 mg of EPA+DHA. Check how many mg of EPA and DHA the dose carries.
What it does
They are fats the body does not make in enough quantity and that go into cell membranes:
- The natural source is oily fish twice a week; the supplement fills what the diet does not give.
- The claims apply only with the amounts of EPA and DHA stated.
- Algae are the option for anyone who does not eat fish.
At the counter
When to recommend it
- A diet without oily fish and an interest in covering the EPA+DHA amount
- Check the mg of EPA and DHA per dose, not those of the oil
- Take it with the fattiest meal of the day; the hour itself does not change the effect
When not to
- On anticoagulants or antiplatelets at high doses without telling their doctor
- More than 5 g a day of supplemental EPA+DHA
- Fish or shellfish allergy without checking first
Warnings
- Important ANTICOAGULANTS AND ANTIPLATELETS: at high doses they may add to a bleeding tendency; tell the doctor before grams a day.
- Caution FISH ALLERGY: read the origin of the oil and check first; algae are an alternative.
- Caution Some trials at high doses (1 g a day or more) have seen more atrial fibrillation: do not offer megadoses without medical indication.
- Worth knowing The fishy aftertaste or burping improves with a meal; a rancid oil smells strong and should be discarded.
Pharmacokinetics
- Absorption
- Better with a meal that contains fat.
- Distribution
- Incorporated into membranes and tissues.
- Metabolism
- In the liver, like other fats.
- Elimination
- Used or oxidised; they do not accumulate like a drug.
Fish oil and algae oil
| Aspect | Fish oil | Algae oil |
|---|---|---|
| Source | Oily fish | Microalgae |
| Carries | EPA and DHA in variable proportion | Mainly DHA, sometimes with EPA |
| Suitable for | Those who eat fish without allergy | Vegetarians and vegans |
| What to check | The mg of EPA+DHA per dose | The mg of DHA and EPA per dose |
In both cases the EPA+DHA amount rules, not the oil amount.
Self-assessment
Three questions. When you check your answers you will see the explanation for each one.
-
The oil carries other fats; the claims speak of EPA and DHA.
-
At high doses they may add to a bleeding tendency.
-
Algae oil supplies DHA, and sometimes EPA, without fish.
Training content. It does not replace the summary of product characteristics or clinical judgement.