Most omega-3 advice flattens three different fats into one number on a label. EPA, DHA, and the lesser-known ETA each do different work in the body, and the source you choose changes what you actually get. In New Zealand, you have three credible options on the shelf: green-lipped mussel, wild salmon, and fish oil. They are not interchangeable.

Which omega-3 source is best for New Zealanders?

The honest answer: it depends on what you are trying to influence. For joint comfort and a broader fatty-acid spread including ETA, green-lipped mussel has a unique profile. For whole-food nutrition with protein, vitamin D, astaxanthin, and a balanced EPA:DHA, wild salmon wins. For dose-controlled EPA or DHA at a known potency, a quality fish oil or concentrated triglyceride-form supplement is the most precise tool.

We use food first with our coaching clients, then layer supplementation when the dataset and the bloods say so. The order matters.

EPA, DHA, and ETA: different jobs

EPA (eicosapentaenoic acid) sits upstream of the resolvin and prostaglandin pathways linked to inflammation modulation. Higher EPA doses, around 1 to 2 g per day, are where most of the mood and cardiovascular trial signal sits.

DHA (docosahexaenoic acid) is structural. It concentrates in neural tissue, the retina, and sperm membranes. If you are pregnant, breastfeeding, training cognitively demanding work, or over 50 and thinking about brain ageing, DHA matters on its own merits.

ETA (eicosatetraenoic acid) is the curiosity. It appears in meaningful amounts in green-lipped mussel and almost nowhere else in the human food supply. Mechanistic work suggests ETA can blunt the COX-2 pathway, which is part of why mussel extracts have been studied for joint symptoms. The human trial base is small but consistent enough to take seriously.

Green-lipped mussel: the NZ specialty

Perna canaliculus is farmed in the Marlborough Sounds and around Coromandel. As whole food, a 100 g serve of cooked mussels delivers roughly 600 to 700 mg of combined omega-3, plus zinc, selenium, iodine, and B12. The fatty-acid spread is wider than salmon: EPA, DHA, ETA, and a string of minor long-chain fats.

As a supplement, green-lipped mussel oil concentrates this profile. Dosing in joint trials typically sits at 200 to 600 mg of mussel oil daily. It is not a high-EPA product. If you want grams of EPA, this is the wrong tool.

Eat the mussels when you can. Steamed, in a chowder, on the barbecue. The food form gives you the protein and minerals as well, and the cost per gram of omega-3 from fresh NZ mussels is lower than most people assume.

Wild salmon: the food-first default

New Zealand king salmon (Oncorhynchus tshawytscha), farmed in the Marlborough Sounds and Akaroa, is one of the fattier salmon species globally. A 150 g cooked fillet delivers roughly 2 to 3 g of combined EPA and DHA, which is more than most supplement servings.

You also get astaxanthin (the pigment that makes the flesh pink and acts as an antioxidant in the oil itself), vitamin D, complete protein, and a satiety profile that supplements cannot replicate. In our 2,846-food dataset, oily fish consistently shows up as one of the highest-leverage swaps for clients trying to lift omega-3 intake without adding capsules.

Two fillets a week, 150 g each, will move your omega-3 index. We have measured it across 1,380+ clients.

Capsules are a tool. Salmon on the plate twice a week is a habit. The habit wins over years.

Fish oil supplements: precision and the oxidation problem

Fish oil earns its place when you need a known EPA or DHA dose. Cardiovascular and mood research using 2 to 4 g of EPA daily is hard to replicate from food alone without overshooting energy intake or mercury exposure.

Three things to check on any NZ fish oil:

  • Form. Triglyceride (TG or rTG) form absorbs better than ethyl ester. Check the label.
  • Oxidation. Independent NZ and Australian testing has repeatedly found supermarket fish oils above the recommended peroxide and anisidine value limits. Rancid oil is pro-inflammatory, the opposite of what you bought it for. Smell the capsule. If it reeks, return it.
  • Dose per capsule. Many "1000 mg fish oil" capsules contain only 180 mg EPA and 120 mg DHA. You may need six capsules to hit a therapeutic dose. Concentrated products are usually cheaper per gram of active.

Store it in the fridge. Buy smaller bottles more often. Check the use-by.

How to choose, in practice

If your goal is general health and you eat fish twice a week, you may not need a supplement at all. We test omega-3 status on bloods alongside your GP when there is a clinical question.

If your goal is joint comfort, green-lipped mussel, food or supplement, has the most NZ-specific case.

If your goal is a measured EPA dose for mood, training recovery, or cardiovascular risk reduction, a concentrated TG-form fish oil at 2 g EPA daily is the cleanest path. Discuss with your GP if you are on anticoagulants.

If you are pregnant, planning pregnancy, or over 50, prioritise DHA. Salmon, sardines, or an algae-derived DHA supplement are all defensible.

What to do this week

  • Put oily fish on the plate twice. Salmon, mussels, sardines, mackerel. NZ-caught where you can.
  • Read the label on your current fish oil. Find the actual EPA and DHA per capsule, not the total oil weight.
  • Smell a capsule. If it is rancid, bin the bottle.
  • If joints are the issue, trial green-lipped mussel oil for 12 weeks at a labelled dose and track symptoms.
  • If you want to know where you actually sit, ask your GP about an omega-3 index test and bring the result to your next coaching review.