Omega 3 fatty acids are important for normal heart, brain and eye function, but how can you get them from your diet and what should you look for when choosing an omega-3 supplement?
🕒 7 min read
What are omega 3 fatty acids?
Omega 3s are a family of polyunsaturated fatty acids. The main forms are alpha-linolenic acid (ALA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA).
ALA is an essential fatty acid, meaning it must come from the diet. It is found in plant foods such as flaxseed, chia seeds, walnuts and rapeseed oil. The body can convert some ALA into EPA and DHA, but this conversion is limited.3
EPA and DHA are the long-chain omega 3s found primarily in oily fish and marine algae. Find out more in our guide to EPA and DHA and why you need both.
What foods contain omega 3 fatty acids?
Oily fish such as salmon, mackerel, sardines, herring and trout are among the richest dietary sources of EPA and DHA.
The NHS recommends eating at least two portions of fish a week, including one portion of oily fish.2
Vegetarian and vegan sources of omega 3 include walnuts, flaxseed, chia seeds, rapeseed oil and hemp seed oil. These mainly provide ALA. Marine algae is different because algae-derived oils can provide EPA and DHA directly.
Oily fish is one of the main dietary sources of the long-chain omega 3 fatty acids EPA and DHA.
If you don't eat fish, algae-derived omega-3 supplements can provide EPA and DHA directly.
Why do you need omega 3s?
EPA and DHA have recognised nutritional roles in the body. EPA and DHA contribute to the normal function of the heart, while DHA contributes to the maintenance of normal brain function and normal vision when the relevant conditions of use are met.1
Heart health
EPA and DHA contribute to the normal function of the heart. The beneficial effect is obtained with a daily intake of 250mg EPA and DHA combined.1
Brain and eye health
DHA contributes to the maintenance of normal brain function and normal vision. The beneficial effect for each claim is obtained with a daily intake of 250mg DHA.1
For a fuller explanation, read our guide to omega 3 benefits for heart, brain and eye health.
How much omega 3 do I need?
There isn't one universal supplement dose that is right for everybody. Dietary guidance and the amount needed to support an authorised health claim are also not the same thing as an individual supplement recommendation.
For example, the authorised heart-health claim for EPA and DHA applies at a daily intake of 250mg EPA and DHA combined, while the authorised claims for DHA and normal brain function and vision apply at 250mg DHA per day.1
One of the most important things to understand when comparing supplements is that the headline amount of fish oil is not necessarily the amount of EPA and DHA it provides.
For a detailed explanation of intake and how to read supplement labels, see how much omega 3 you should take per day.
What should you look for in an omega-3 supplement?
The best omega 3 supplement for you depends on how much EPA and DHA it provides, its source, strength and quality, and whether you need a fish-based or vegan option.
When comparing products, look beyond the number printed prominently on the front of the pack. A product labelled “1,000mg fish oil”, for example, does not necessarily contain 1,000mg of EPA and DHA. The EPA and DHA figures in the nutritional information are more useful when comparing omega-3 supplements.
You can compare Healthspan's full omega-3 supplements range, including fish-oil and vegan alternatives.
EPA vs DHA: what's the difference?
| Omega-3 fatty acid | Recognised role | What to check on the label |
|---|---|---|
| EPA | EPA works with DHA to contribute to the normal function of the heart. The beneficial effect is obtained with 250mg EPA and DHA combined each day. | Check the stated amount of EPA per recommended serving rather than relying only on the total fish-oil figure. |
| DHA | DHA contributes to normal heart function alongside EPA and also contributes to maintenance of normal brain function and normal vision. | For the authorised brain and vision claims, the beneficial effect is obtained with 250mg DHA per day. |
Neither EPA nor DHA is simply “better”. The right balance depends on why you are choosing an omega-3 supplement and the amount supplied by the recommended serving.
Strength
The headline amount on a pack often refers to the total amount of fish oil rather than the amount of EPA and DHA.
For example, Healthspan's Super Strength Omega 3 1200mg contains 1,200mg fish oil concentrate per capsule but provides 360mg EPA and 240mg DHA – 600mg EPA and DHA combined.4
A more concentrated product can therefore provide more EPA and DHA without necessarily requiring more capsules. Always compare the amounts provided by the recommended serving.
Quality and purity
Look for a manufacturer that clearly explains where its oil comes from, how it is purified and what quality standards are used.
Marine oils can contain environmental contaminants if they are not appropriately processed, so transparency around purification and quality testing is useful when comparing products.
Sustainability is also worth considering. Recognised certifications such as Friend of the Sea or the Marine Stewardship Council can provide additional information about how marine ingredients are sourced.
Vegetarian or vegan
If you are vegetarian, vegan or do not want to use fish oil, algae-derived omega 3 provides EPA and DHA directly.
For example, Healthspan's Veg-Omega® 3 1000mg provides 340mg DHA and 170mg EPA per capsule from microalgae and is suitable for vegetarians and vegans.6
Omega 3 doesn't have to come from fish. Algae-derived supplements provide a direct vegetarian and vegan source of EPA and DHA.
Find out more
Absorption, format and reflux
Omega-3 products can also differ in the form of oil they use and the way the capsule is designed.
Healthspan's Opti-Omega® 3, for example, provides EPA and DHA in triglyceride form. Each capsule provides 320mg EPA and 320mg DHA, while its gastro-resistant shell is designed to release the oil in the intestine rather than the stomach, helping to reduce the fishy aftertaste and reflux sometimes associated with fish oil.5
If capsules are difficult to swallow, omega 3 is also available in other formats including liquids and gummies. The most appropriate choice is one that suits your diet and preferences while providing clearly stated amounts of EPA and DHA.
Omega-3 supplement safety
Always follow the directions on the individual supplement and do not exceed its recommended daily intake. Food supplements should not be used as a substitute for a varied, balanced diet and healthy lifestyle.
Fish-oil supplements can cause effects such as an unpleasant aftertaste or digestive discomfort in some people.
If you take prescribed medication, have a medical condition, are pregnant or breastfeeding, speak to a doctor, pharmacist or other appropriate healthcare professional before starting a supplement. Current Healthspan omega-3 product guidance includes the same precaution.4
