Why is there a controversy about omega3 fatty acids?

Supermarkets and food companies were accused this week by Which?, the consumer watchdog, of confusing shoppers about the health benefits of omega3 and cashing in on health-conscious consumers who may be willing to pay more for products that they believe are good for the heart. It claimed that more than half of the products promoted for health would make little difference to a person’s wellbeing.

So what are omega3 fatty acids and why should we eat them?

Omega3 is a family of polyunsaturated, essential fatty acids that have been shown to help to protect against coronary heart disease. Their importance in the diet was first highlighted in 1992 by William E. M. Lands, an American nutritional biochemist, in his book Fish, Omega3 and Human Health. The fatty acids that are most beneficial to health are found in oily fish. These are known as EPA (eicosapentaenoic) or DHA (docosahexaenoic) acids. As well as being good for the heart, some research suggests that a combination of EPA and DHA is also good for the brain and can aid concentration.

The Food Standards Agency is at present conducting trials to see if there is any evidence that omega3 can slow the onset of memory decline in old age as seen in early stages of Alzheimer’s disease.

Omega3 fatty acids are also found in plants, nuts, seeds and some vegetable oils, but these are known as ALA (alphalinolenic acid) and are less beneficial to health.

How easy is it to find foods on sale with the good fatty acids?

That is the crux of the problem. Many items sold and promoted for omega3 do not specify the type of fatty acid contained in the product on the label or packaging. Manufacturers need to be clear and state explicitly if a product contains EPA and DHA, the good fatty acids, or ALA, which is less beneficial.

So how much omega3 should we be eating?

Three years ago the Scientific Advisory Committee on Nutrition and the Committee on Toxicity concluded that a minimum of 0.45g a day, or 3g a week, of EPA and DHA, eaten as part of a balanced diet, would help to keep the heart in good shape.

People can easily obtain the good fatty acids by eating a portion of oily fish, such as mackerel, which will provide 2-3g of the 3g recommended weekly intake. In Britain there is no recommmended daily amount for omega3 because it is not clear how much is needed to obtain the maximum benefit.

Scientific research has found that cholesterol levels dropped by 50 per cent in patients who ate 4g of EPA and DHA a day.

The American Food and Drug Administration advises consumers not to consume more than 3g a day of long-chain omega3 – this includes a maximum of 2g a day from supplements.

Anyone taking blood-thinning medication such as daily aspirin or warfarin should speak to a GP before eating lots of food with added omega3 or before taking fish-oil supplements, as this could also reduce blood clotting.

So which foods should we be eating to benefit from these fatty acids?

Oily fish is the best source for the good omega3 fatty acids. Fish such as whitebait, sardines, herring, mackerel, trout, salmon, pilchards, kipper, eel, fresh tuna, anchovies, swordfish, bloater, cacha, carp, hilsa, jackfish, katla, orange roughy, pangas and sprats are rich sources.

Tinned oily fish, except for tuna, can also be a good source of omega3. Unlike other fish, tuna is cooked twice when it is canned so that more of the omega3 is destroyed. Nevertheless, a recent test by Which? found that a can of John West tuna contained 0.19g of omega3 per 100g, of which 0.18g was EPA and DHA. This was a better fatty acid content than many other products tested. Shellfish, such as crab and mussels, are also quite good sources of omega3, but prawns contain hardly any.

Bear in mind that the official advice from the Government is that we should eat two portions of fish a week, one of which should be oily.

It also suggests that the maximum amount of oily fish a week should be four 140g portions, though girls, women who might wish to be pregnant one day, and pregnant and breast-feeding women are recommended to eat a maximum of two 140g portions of oily fish. This is because of low-level pollutants that are found in fish and can harm the development of a baby in the womb and the newborn.

Are there any other foods that contain omega3 fatty acids?

The fatty acids that are less good for the heart contain ALA and are from plants, seeds, nuts and are found in some vegetable oils such as linseed, flaxseed, walnut and rapeseed.

Supermarkets and food companies, desperate to exploit the trend for healthy eating, have started producing bread, fruit juices, yoghurt, margarines, eggs and even baked beans that contain omega3.

The stampede to put omega3 products on supermarket shelves began in 2004 after the Government gave official backing to scientific research that highlighted health benefits for the heart. There were 154 products in the first year and the product ranges are being increased substantially each year.

The market for omega3 products is now worth £116 million a year and, according to Frost & Sullivan, a global research company, it is expected to grow by at least 8 per cent within three years.

There is research under way to insert genes from good fatty acids into rapeseed, a crop used to feed farm animals. Trials are also being conducted to produce the first chickens with omega3.

Is there something we can do to persuade food companies to give us accurate health benefits on products?

Yes. Shoppers can start bombarding customer-service staff with questions about which fatty acids are contained in products. Consumers can also contact food company customer-care lines or websites.

Another tactic is to “name and shame” products that fail to live up to their claims.

Supermarkets will already be scrutinising labels and checking claims after Asda was caught out this week by Which? for making false claims on its 400g Healthy Wholegrain bread. It has withdrawn the product from sale while packaging is being redesigned.

The label on the bread started out by extolling the benefits of omega3 from fish and admitting that it was harder for the body to access omega3 from plant sources. It then stated: “That’s why Asda is using special linseed which has been heated in order to liberate the beneficial oils.”

The watchdog said: “This baffled our experts as linseed [from flax] contains primarily ALA. What’s more, heat and exposure to light and air tend to destroy valuable omega3.”

New EU laws will prevent companies from making misleading health and nutrition claims on labels, but these will not be implemented for several years. As yet there is no requirement relating to omega3.

Consumers may find that a letter to the Food Standards Agency to demand change may also help.

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