Could the mercury in tinned fish be making arthritic pain worse?
Q) My friend eats tinned mackerel every day and suffers from arthritis, which is worsening. I understand there's a high content of mercury in oily fish and know that for this reason it's only recommended that you eat it twice a week when pregnant. Might there be a connection between mercury poisoning and arthritis?
Alison, Ormskirk (Autumn 2011)
A) I think the main problem with eating too much oily fish in pregnancy isn't the mercury content but the vitamin A content. Oily fish is good for you in many ways: it's high in vitamin D (and vitamin A) and is full of omega-3 fatty acids, which are good for the heart. The omega-3 fatty acids are also of help in controlling the pain of arthritis. I think the scare with mercury related mostly to whale and dolphin but, in any case, mercury is more likely to cause damage to skin, nerves, lungs and kidneys, not arthritis. High quantities of vitamin A can harm the growing foetus, hence the strictures on oily fish intake.
This answer was provided by Dr Philip Helliwell for the Autumn 2011 edition of our magazine, Arthritis Today, and was correct at the time of publication.
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