Few people know the health benefits or pitfalls of eating oily fish, according to a survey by the Consumers' Association.
Eating fish can reduce the risk of heart attacks and help blood circulation, the watchdog says in its magazine Which?
But certain oily species such as salmon, trout and mackerel run the risk of being contaminated with chemicals, while shark, marlin and swordfish might contain high levels of mercury, the report said.
Which? spoke to consumers to assess how many knew the current advice from the Food Standards Agency (FSA) about eating oily fish. Only 7 per cent could remember recent FSA guidance on mercury and fish, but none knew the details. One per cent recalled the agency had recommended that pregnant women avoid eating shark, swordfish and marlin. It extended the advice to women planning on becoming pregnant, and to children under 16. Only one sixth knew FSA advice that consumers should eat at least two portions of fish a week, of which one should be oily.
At the root of the problem is lack of knowledge about what is classed as oily fish, Which? says. Most could not name all the species available in the UK – herring, kippers, mackerel, marlin, pilchards, salmon, sardines, sprats, swordfish, trout and fresh tuna.