Omega-3 Explained: EPA, DHA, Fish Oil and Algae DHA

Omega-3 is one of the most familiar words on the supplement shelf, but the labels behind it vary a lot. Fish oil, krill oil and algae products all say "omega-3" on the front, yet the amounts of EPA and DHA inside can differ several times over. This guide explains what omega-3 fatty acids are, where they come from and how to compare labels properly.

What are omega-3 fatty acids?

Omega-3s are a family of polyunsaturated fats. The three you will see most often are:

• ALA (alpha-linolenic acid), found in plant foods such as flaxseed, chia seeds, walnuts and rapeseed oil
• EPA (eicosapentaenoic acid), found mainly in oily fish and seafood
• DHA (docosahexaenoic acid), also found mainly in oily fish and seafood, and in certain algae

The body can convert only a small proportion of ALA into EPA and DHA, which is why EPA and DHA are usually listed separately on supplement labels.

What can be said about EPA and DHA

Two authorised health claims apply, each with a condition that must be met:

• EPA and DHA contribute to the normal function of the heart. The beneficial effect is obtained with a daily intake of 250 mg of EPA and DHA.
• DHA contributes to maintenance of normal brain function. The beneficial effect is obtained with a daily intake of 250 mg of DHA.

That is why the EPA and DHA figures on a label matter so much: they tell you whether a daily serving reaches those amounts.

Where does omega-3 come from?

Oily fish such as salmon, mackerel, sardines, herring and trout are the richest food sources. NHS advice is to eat at least two portions of fish a week, one of which should be oily. Fish do not make most of their EPA and DHA themselves: they get it from the algae and plankton they eat. That is why algae can be used as a fish-free source of DHA, and why krill, a small crustacean, also contains omega-3.

Forms and what to look for on a label

• EPA and DHA in milligrams. "1000 mg fish oil" describes the oil, not the omega-3 in it. Look for the EPA and DHA figures underneath.
• Per serving, not per capsule. Add up the EPA and DHA in the full daily serving and compare it with the 250 mg figures above.
• Source. Fish, krill or algae. Krill products contain crustaceans.
• Capsule type. Fish oils usually come in gelatin softgels, which are not suitable for vegetarians. Algae products are often in plant-based capsules.
• Allergens. Fish and crustaceans must be declared.

How people take it

Take omega-3 as stated on the label, at the serving given, and do not exceed the recommended daily dose. Many labels suggest taking it with food. If you also take cod liver oil or another omega-3 product, include it when you work out your total.

Who should check with a doctor or pharmacist first

Speak to your doctor or pharmacist before taking an omega-3 supplement if any of the following apply to you:

• you are pregnant, trying for a baby or breastfeeding
• you take any prescription medication or are under medical supervision
• you are under 18 (our products are not intended for anyone under 18)
• you take anticoagulant or antiplatelet (blood-thinning) medicines
• you are allergic to fish or crustaceans

Frequently asked questions

Is algae omega-3 as good as fish oil?

They are different sources. Algae products are usually rich in DHA and lower in EPA, while fish oils contain both. Compare the EPA and DHA figures per daily serving on each label.

Why is my 1000 mg capsule not 1000 mg of omega-3?

The 1000 mg is the total oil. Only part of that oil is EPA and DHA, and the label lists those amounts separately.

Can vegans get EPA and DHA?

Yes, from algae-based products. Check that the capsule shell is plant-based too.

Mother Nature products

• Omega 3 Fish Oil 1000mg Softgels, 500mg EPA and 200mg DHA: 500 mg EPA and 200 mg DHA per softgel, which is 700 mg of EPA and DHA combined. 1 to 2 softgels daily with food. Contains fish; bovine gelatin softgel.
• Omega 3 Fish Oil 1000mg Softgels, 180mg EPA and 120mg DHA: 180 mg EPA and 120 mg DHA per softgel, 300 mg combined. 1 to 2 softgels daily with food. Contains fish; bovine gelatin softgel.
• Omega 3 Algae DHA 500mg Capsules: 500 mg algae DHA powder per capsule providing 100 mg DHA, or 200 mg DHA in the daily serving of 2 capsules, preferably with a meal. Fish-free and suitable for vegans. Note that 200 mg is below the 250 mg DHA daily intake linked to the claim above.

Find more everyday essentials in our Daily Foundations collection.

Food supplements should not be used as a substitute for a varied and balanced diet and a healthy lifestyle.