Ask Marilyn: Toxic fish?
Q: Could the fish I’m eating be toxic?
A: Fish is a superb source of protein and is packed with essential omega fats and is a great source of calcium, selenium, vitamin D and E so I’m glad you are including it in your diet. Having said that, the fish you are eating may contain mercury – a heavy metal that can cause nerve damage in high doses due to pollution getting into the rivers and seas. However, levels of this heavy metal are not high enough to do you any harm in the quantities most people consume them.
Research does, however, show that swordfish and marlin contain the highest levels, due to their size, where they feed and the age they live (which concentrates the mercury). These fish are closely followed by tuna. If you are pregnant or trying to conceive the Food Standards Agency suggests limiting your intake of these fish or avoiding them altogether. It’s fine, however, to eat plenty of smaller fish like sardines, salmon, trout and mackerel which are low in these toxins and no threat to your health and wellbeing.