There’s no denying that eating fish is good for you. One of the key reasons is that it’s a great source of polyunsaturated fat – in particular the omega-3 fats called EPA and DHA. These fats are help reduce inflammation, clotting, high triglycerides (a type of fat in the blood) and help keep the blood vessels flexible. They are a critical part of brain growth and visual and nervous system development. Some parents and teachers swear by fish oil as a solution to lack of concentration and unruly behaviour in kids although the scientific evidence is not so certain about this.

The Nutrient Reference Values for Australia and New Zealand have a ‘suggested dietary target’ of 610mg per day for men and 430mg per day for women of long-chain omega-3’s. Take note of the words ‘long chain’. All omega-3’s are not equal. There’s long chain which are found in fish and seafood, and then there are short chain which are found in canola, soybean, linseed, walnuts, green vegetables, eggs and lean meat. It’s the long chain ones that are so valuable to our health. Although our body is fantastic at converting one substance into another, it hardly converts any short chain omega-3’s into long chain. There must be a good reason for this but I don’t know what it is. Anyway the main point of all this is that we need to know what type of omega-3 we’re eating.

Long chain and short chain all sounds a bit scientific so the Australian Heart Foundation has brilliantly come up with some more food oriented classifications: marine sourced, plant sourced and animal sourced – much easier to understand. To reduce our risk of heart disease it recommends we eat 500mg per day of marine-sourced omega-3 and another 2 grams per day of plant sourced omega-3. Two or three fish meals a week (marine source) plus a couple of slices of soy and linseed bread or a small handful of walnuts (plant source) each day about does it.

If you have a can of tuna in the cupboard, take a look at the label. A quick glance shows that a 95gram can of tuna has 1.1grams of omega-3 – great! But a closer look reveals that only 85mg of it is EPA and DHA. The rest of it comes from the soybean oil that the tuna is canned in. The same with my frozen fish fillets: one fillet has 684mg of omega-3. That’s more than met my 500mg per day quota right? Actually only 206mg is EPA and DHA. The other 478mg is from canola oil. There’s nothing wrong with this but it pays to be aware that looking for omega-3 on a label is not enough. It’s the marine sourced EPA and DHA that we really need to ensure we get enough of.