Nutrient ingredient
Omega-3 fatty acids: What It Is, What the Evidence Shows and How to Choose a Supplement
Also known as EPA, DHA, fish oil, algal oil
Omega-3 supplements are judged on two numbers most labels bury: the actual EPA and DHA per capsule. A 1000 mg fish oil softgel often supplies only 300 mg of the fatty acids that matter.
What is omega-3 fatty acids?
The long-chain omega-3 fatty acids EPA and DHA come mainly from oily fish. ALA, the plant form found in flaxseed and chia, converts to EPA and DHA only inefficiently.
Lake Victoria and coastal fisheries make oily fish accessible in parts of East Africa, but intake varies widely between inland and coastal diets.
Traditional and regional use
Fish has always been a dietary staple around Lake Victoria, Lake Tanganyika and the Indian Ocean coast. Concentrated fish oil supplements are a modern import.
What does the research say?
Evidence, not endorsement. What follows describes published research about the ingredient. It is not a claim about any specific product, and no supplement containing this ingredient may claim to treat a disease.
Omega-3 intake and cardiovascular outcomes have been studied extensively, with large trials producing mixed results and effects that depend on dose and baseline intake.
Evidence for triglyceride reduction at higher doses is consistent and well documented.
DHA has a defined role in eye and brain development, which is why it appears in pregnancy and infant nutrition.
How is it used in supplements?
Omega-3 appears in cardiovascular, joint, brain and eye formulas. Concentrations range from ordinary fish body oil to high-concentrate ethyl ester and triglyceride preparations.
Forms and sources
- Fish body oil softgels
- High-concentrate EPA/DHA preparations
- Cod liver oil (also supplies vitamins A and D)
- Algal oil for vegetarians
Safety
- Generally well tolerated. Fishy aftertaste is the most common complaint.
- High doses may increase bleeding tendency modestly.
- Cod liver oil also delivers vitamin A, which has its own upper limit — do not treat it as interchangeable with plain fish oil.
Possible side effects
Fishy burps, nausea and loose stools. Freezing capsules or taking them with meals reduces the aftertaste.
Interactions
May add to the effect of anticoagulant and antiplatelet medication at higher doses.
Who should seek professional advice
Anyone on anticoagulants, anyone with a fish or shellfish allergy, and anyone taking cod liver oil alongside another vitamin A source.
How to choose a supplement containing omega-3 fatty acids
- Read the EPA and DHA milligrams per capsule, not the total oil weight.
- Check for a freshness or oxidation statement; rancid oil smells strongly fishy.
- Vegetarians should look for algal oil, which supplies DHA directly.
Supplement categories using this ingredient
Related health topics
Frequently asked questions
Is flaxseed oil the same as fish oil?
No. Flaxseed supplies ALA, which the body converts to EPA and DHA at a low rate. If you want EPA and DHA, use fish or algal oil.
How much EPA and DHA per day?
General intake guidance for adults sits in the range of a few hundred milligrams combined per day. Higher therapeutic doses are a medical decision.
Related ingredients
References
Medical disclaimer. BioMedic Africa publishes consumer health information and supplement research summaries. It is not a pharmacy, a clinic or a medicines regulator, and nothing here is a diagnosis, a prescription or a treatment plan. Dietary supplements are foods, not medicines: they are not intended to diagnose, treat, cure or prevent any disease. Speak with a pharmacist or a qualified healthcare professional before starting any supplement, especially if you are pregnant or breastfeeding, under 18, living with a long-term condition, or taking prescription medication.