It is vital that manufacturers and suppliers of these products ensure that they do not contain high levels of dioxins

Professor Tom Saldeen

The study was carried out in advance of new EU safety limits for dioxins in foodstuffs that come into force in July.

It found that the dioxin level in 10 brands of fish oil and fish liver oil capsules exceeded the new European maximum limits.

In one case the dioxin level was five times the maximum limit.

The majority of the products tested are available in the UK.

Dioxin levels were higher in those brands containing fish liver oil, rather than fish body oil.

However, the fish liver oil brands that exceeded the maximum limit account for only 10% of the total market in Ireland.

The fish oil supplement with the lowest level of contaminants was Eskimo-3 Stable Fish Oil Supplement.

The FSAI said the levels of dioxins detected posed no health risk as long as consumers used the supplements in accordance with manufacturer's instructions.

This study was carried out so that manufacturers could take appropriate action before the July deadline.

Health benefit

Professor Tom Saldeen has researched the effect of fish oils and Omega-3 fatty acids in nutrition for almost 20 years.

He said: "Long-term international research indicates that Omega-3 fatty acids, common in the diet of Eskimos, is largely responsible for their low incidence of cardiac disease, and can help keep joints supple and contribute to a clear skin.

"Fish oil supplements are bought for health reasons for their Omega-3 fatty acid content and it is therefore vital that manufacturers and suppliers of these products ensure that they do not contain high levels of dioxins."

Dioxins are naturally occurring in the environment and accumulate in the fat of animal species or in plant tissue.

Consumption of dioxins above safe levels over a lifetime may result in an increased risk of cancer.

The researchers also looked at dioxin levels in Irish farmed trout and salmon.

They found that levels in these fish were well below the maximum limit.