Omega 3 fish oil: what it is and what the research says
26 October, 2026Short answer: Omega 3 fats, mainly EPA and DHA from oily fish, are fats the body gets from food. A large Cochrane review found that taking more omega 3 supplements makes little or no difference to deaths or heart events. It did find that they probably lower triglycerides, a type of blood fat. Eating oily fish is still part of a healthy diet.
What omega 3 is
Omega 3 fatty acids are a type of polyunsaturated fat. The body cannot make them in useful amounts, so they come from food. EPA and DHA are found mainly in oily fish such as salmon, sardines and mackerel. ALA is a plant omega 3, found in nuts and seeds such as flax.
What is in a capsule
Each NZ Pure Health Omega 3 soft gel capsule contains 1000mg of fish oil, which provides 180mg of EPA and 120mg of DHA, plus 1.15mg of vitamin E. The oil comes from smaller cold water fish, sardines and anchovies, harvested from the South Pacific. There are no artificial flavours, colours or preservatives.
What the research says
In 2018, Cochrane published a systematic review of 79 randomised trials with 112,059 people. It looked at whether long chain omega 3 fats (EPA and DHA) change the risk of death, heart disease or stroke.
- High certainty evidence showed that EPA and DHA make little or no difference to the risk of death from any cause. About 8.8% of people died with increased intake, and 9% in the comparison groups.
- They probably make little or no difference to cardiovascular events, deaths from coronary heart disease, stroke or heart rhythm problems.
- They probably lower triglycerides.
- The review could not tell whether eating more oily fish protects the heart, because few trials tested whole fish. The lead author still described oily fish as a healthy food.
Some researchers disagree with how the review treated the evidence, so the debate is not settled. What is fairly clear is that omega 3 capsules are not a substitute for a healthy diet or for medicines your doctor has prescribed.
Who should talk to a healthcare professional first
- Anyone who is pregnant or breastfeeding.
- Anyone taking prescription medicine, especially blood thinners.
- Anyone with a fish allergy, as this product comes from fish.
- Anyone managing a heart condition or high triglycerides.
How to take it
Take one or two capsules daily as a dietary supplement, or as professionally advised.
Common questions
Is fish oil better than eating fish?
The evidence is unclear. Eating oily fish provides protein and other nutrients as well as omega 3, so it remains a good choice.
What about flax oil?
Flax oil contains ALA, the plant omega 3. The Cochrane review found that ALA probably makes little or no difference to deaths and may very slightly lower the risk of heart rhythm problems. About 1,000 people would need to increase their ALA for one person to benefit.
How long until I notice anything?
Trials of omega 3 ran for months to years. Many people notice nothing, and that is normal.
Sources
- Cochrane, 16 July 2018. New Cochrane health evidence challenges belief that omega 3 supplements reduce risk of heart disease, stroke or death. Based on Abdelhamid AS and colleagues, Omega 3 fatty acids for the primary and secondary prevention of cardiovascular disease, Cochrane Database of Systematic Reviews, CD003177. cochrane.org
Written by Liz Lawton. Last updated 26 October 2026. This article is general information and is not medical advice.
