Omega-3 fish oil: what to look for, and how much (UK guide)

How much omega-3 do you need?

The UK guidance, from SACN and echoed by the NHS, is to eat two portions of fish a week, one of which is oily, such as salmon, mackerel, sardines or herring. That is the food-first way to get the long-chain omega-3s EPA and DHA. Plenty of people do not manage it, whether by taste, cost or diet, and that is the gap a supplement fills. There is no single official daily milligram target for healthy adults in the UK, which is part of why omega-3 labels are so inconsistent, but the oily-fish advice is the anchor to work from, and a daily EPA and DHA supplement is a reasonable way to cover a diet that is short of fish.

EPA and DHA: the two that actually matter

Omega-3 is a family of fats, and not all of them are equal. The two long-chain forms, EPA and DHA, are the ones found in oily fish and the ones most of the interest is about. There is also a shorter-chain plant omega-3, ALA, found in flaxseed and walnuts, but your body converts only a small share of it into DHA, so it is not a reliable stand-in for the long-chain forms. This is why the figure to find on any omega-3 product is the EPA and DHA content, not the total omega blend or the oil weight. A big number on the front of the bottle can still hide a small amount of the parts that count.

Fish oil or vegan algal oil?

Both routes get you there, and the right one depends on your diet.

• Fish oil provides both EPA and DHA together, which is why it is the common choice for anyone who simply does not eat enough oily fish.
• Algal oil is grown from marine algae, the original source fish get their omega-3 from in the first place, and it is the plant-based route. Most algal oils are DHA-led.

If you eat no fish, or you follow a plant-based diet, the algal oil is the one to read about, and the vegan omega-3 guide covers it in full. If you are happy taking fish oil, it is the simplest way to get EPA and DHA in one capsule.

The triglyceride form, and why it is worth checking

Here is the detail most omega-3 pages skip. Fish-oil supplements come in a couple of chemical forms. In the triglyceride form, the omega-3 sits on the same glycerol backbone it has in fish. To concentrate the EPA and DHA, a fish oil is often first turned into an ethyl ester, and a triglyceride-form oil is then converted back to that natural backbone, which is known as a re-esterified triglyceride. Both the natural and the re-esterified triglyceride are in the triglyceride form that matches how omega-3 occurs in fish; the ethyl ester is the other main type on the shelf. All of them deliver EPA and DHA, so this is a quality-and-closeness-to-food point rather than a safety one. Ours is a re-esterified triglyceride, so it sits in that triglyceride form.

How to read an omega-3 label

The skill is the same one that works on any supplement: ignore the front, read the back.

• Find the EPA and DHA amounts per serving. That is what you are buying.
• Check the serving size. A low per-capsule amount can mean two or three capsules to reach the figure quoted.
• A large “fish oil” or “omega oil” number is the total oil, not the EPA and DHA in it.
• Look for the form. A triglyceride-form oil, whether natural or re-esterified, is the one that matches fish; the ethyl ester is the other main type.

Which one should you choose?

If you do not eat much oily fish and you are happy taking fish oil, our premium omega-3 is a one-a-day softgel providing 729 mg of EPA and 275 mg of DHA in the triglyceride form, as a re-esterified triglyceride. 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, which one softgel provides several times over. DHA also contributes to the maintenance of normal brain function and to the maintenance of normal vision; the beneficial effect there is obtained with a daily intake of 250 mg of DHA, which the 275 mg in a softgel meets. If you would rather a plant-based route, the vegan algal omega-3 is the one to read about instead.