Is cod liver oil detrimental rather than beneficial to osteoarthritis sufferers?
Q) I heard in the media recently that, contrary to previous advice, taking cod liver oil capsules is detrimental rather than beneficial to sufferers from osteoarthritis. Have you any advice to offer on the subject? If you're in favour of cod liver oil can you offer any advice on dosage? Up to now my husband and I have been taking 1,000 mg capsules per day.
Madeleine Harmes, Hayes, Bromley, Kent (Spring 2005)
A) Cod liver oil, being rich in omega-3 fatty acids, may help the pain and inflammation of established arthritis and it contains vitamin D, which is good for healthy bones. For this reason I recommend it to all my patients with osteoarthritis. Cod liver oil also contains vitamin A, which can be harmful in large doses, particularly to pregnant women. The daily maximum dose of vitamin D is 50 micrograms and for vitamin A is 3 mg. The recommended daily intake of these vitamins is about a fifth of these values. You'll be well within the recommended daily doses of these vitamins if you're taking 1,000 mg of cod liver oil (but you can check the label anyway). As to the optimal dose, no-one knows, but Prof. Caterson and colleagues in Cardiff chose the 2,000 mg dose for the purposes of their recent trial.
Editor's Note: Results (as yet unpublished) of the Cardiff clinical trial of 25 arthritis patients awaiting knee replacement surgery showed that 86 per cent of patients who took 2,000 mg of cod liver oil capsules daily had absent or significantly reduced levels of one of the enzymes that cause cartilage damage, compared to 26 per cent of those given a placebo oil capsule. In addition, the result showed a marked reduction in some of the enzymes that cause joint pain in those patients taking the cod liver oil.