How often should we eat oily fish?

Alyson Craig, Greenland

Oily fish provide us with a rich source of omega 3 polyunsaturated fatty acids. Medical studies have shown that omega 3 fatty acids reduce the risks of heart disease and have beneficial effects on cardiovascular risk factors, such as reducing plasma triglycerides and blood pressure. Seafood in general contains an abundance of essential minerals which include, iron, zinc, iodine and selenium. Fish is also a good source of vitamins. Our recommendation of oily fish like salmon, mackerel, herring, sardines, eels and swordfish is that everyone should try to eat at least two portions of fish a week (one portion is 140 g) and at least one of them should be oily. There have been reports in the news over the last years that there could be health risks associated with eating too much oily fish. This is because oily fish can contain dioxins and PCBs (polychlorinated biphenyl). Dioxins are by-products from certain industrial processes and household fires. They are found throughout the environment and in all fishes. PCBs were used mainly in the manufacture of electrical equipment but they haven’t been used since the 1970s. Levels of both dioxins and PCB’s are falling throughout the environment, and in the food we eat. Neither have any immediate effect on health; the risk comes from eating very high levels of both over a long period of time. Both are persistent compounds that accumulate in the food chain in fish and in fat. Nowadays, the amounts of dioxins present in fish are below the safety levels set by the World Health Organization (WHO) and the European Union (EU). These limits are based on achieving minimum risk for someone consuming relatively large amounts of the food in question throughout their lifetime. Therefore, there is no reason to avoid eating farmed salmon or any other fish.