Many products contain added omega 3 - but you can't always trust the claims on food labels.
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Food labels that mislead and confuse are plentiful when it comes to omega 3. The latest Which? Report uncovered labels with claims that are inaccurate at best or just plain wrong.
Which? also tested the amount of omega 3 in a range of products - from oily fish where it occurs naturally to foods where it has been added - and found up to 1,000% more or 98% less than the quantity declared. And even the omega 3 that is present may not be doing you as much good as you think.
Plant-based vs oily fish-based omega 3
Omega 3 from fish is more beneficial than from plants.
Omega 3 from plants is not as beneficial as that from fish, but this difference is rarely made clear on food labels.
Oily fish-based sources contain more of the long-chain fatty acids EPA and DHA, which are most beneficial for healthy hearts, while plant-based sources have more shorter-chain fatty acids, such as ALA, which our bodies have to convert to EPA and DHA.
One product we looked at, Hellmann's mayonnaise, states it's 'a good natural source of omega 3 from plant sources' but doesn't spell out that there's hardly any EPA and DHA in this high-fat, high-calorie food.
Getting the advised amount
Even products with added fish oil often fail to say just how much you'd have to eat or drink to get a useful amount of omega 3.
Tesco's Healthy Living pomegranate juice drink with added omega 3 says: 'DHA/EPA may be good for joint mobility and helps the normal development of brain tissue and nerve growth in unborn babies.this is a delicious way to get your recommended amount!'
But its label shows it contains just 0.03g per 100ml of omega 3 from fish oil - to get the advised amount (see How much to eat') you'd have to drink 1.5 litres a day.
A voluntary code of practice for the food industry says to make a heart-health claim, foods should contain a significant amount of long-chain fatty acids (including EPA and DHA) - at least 0.2g per serving.
However, Müller Vitality 0.1% yogurt drink with omega 3 contained less than this per serving but on its packaging it still highlighted the benefits that omega 3 can have on the heart. Müller told us the claim 'refers to the nutrient, not a serving of our product'.
Labelling that's plain wrong
Asda's Healthy wholegrain bread with confusing label.
The label on Asda's Healthy wholegrain bread (400g) starts with 'omega 3 has been shown to be protective against heart disease - the most efficient source is from fish.with plant sources it's harder for the body to access the omega 3 and use them'.
So far, so good, but it's followed by 'that's why Asda is using special linseed which has been heated in order to liberate the beneficial oils'. This claim baffled our experts as linseed (from flax) - like other plant sources - contains primarily ALA. What's more, heat and exposure to light and air tend to destroy valuable omega 3.
ASDA's incorrect label will now be redesigned
The label also claims 4 slices provide 31.3g of omega 3, but our tests revealed this bread had just 0.009g of DHA/EPA per 100g, so you'd need to eat just over 11 loaves a day to get your daily amount.
When we spoke to Asda, it said this labelling 'may be confusing to customers' and admitted a typing error with the amount of omega 3 per 4 slices. It agreed to withdraw the bread from sale while the packaging was redesigned.
As with all nutrients, the amount of omega 3 shown on a food label is an average. It's tricky for food companies to determine accurately the omega 3 in fish products, as it varies depending not only on the type of fish but where it was caught, whether the fish is in breeding season, and even how long it takes to get to the processing plant.
For example, Tesco labels its wild Alaskan salmon fillets as having 600mg (0.6g) per 100g of omega 3, while its standard farmed salmon fillets are labelled as having 3,200mg (3.2g) per 100g.
Tesco told us: 'Wild salmon is leaner and has a much lower total fat content (and therefore less omega 3) than farmed salmon, which is linked to the feed the farmed fish are given.' Our tests confirmed similar differences between levels in the farmed and wild fish.
In May 2007, we asked 2,405 of our online panel members about omega 3. In July and August we picked 34 products from major supermarkets that were promoted as containing or being high in, omega 3 on the front of the packs and had one of each of them analysed by a lab.
Which? has lobbied hard for a system to make food companies back up their health claims on products. We have had success - new EU laws should stop misleading claims, but it'll be a few years before this legislation is fully implemented, and as yet there's nothing in it relating specifically to omega 3. We'd like this to be a priority.