A daily dose of cod liver oil can cut painkiller use in patients with rheumatoid arthritis, a study suggests.
Cod liver oil can be taken in capsule or liquid form
Taking 10g of cod liver oil a day reduced the need for non-steroidal anti-inflammatory drugs (NSAIDs) by 30%, Dundee University researchers say.
Concerns about side-effects of NSAIDs has prompted research into alternative.
Rheumatologists said the study, in Rheumatology journal, funded by Seven Seas, was small but showed fish oil could benefit some patients.
Patients in the trial were either given cod liver oil or placebo and after 12 weeks asked to gradually reduce their use of NSAIDs, such as ibuprofen.
Almost 60 patients completed the nine-month trial which found 39% taking cod liver oil reduced their daily dose of NSAIDs compared with 10% taking a placebo.
The reduction in drug use was not associated with any worsening of pain or the disease, the researchers reported.
The research team at the University of Dundee, aided by colleagues at the University of Edinburgh, have now completed three studies which have all shown patients are able to cut down their NSAID use when taking cod liver oil.
It is thought fatty acids in the fish oil have anti-inflammatory properties.
Some side-effects of NSAIDs, such as an increased risk of stomach bleeding have been known for a long time.
But more recently, concerns have been raised about an apparent increased risk of heart attacks and strokes in those taking the drugs.
Study leader Professor Jill Belch said the study offered hope to many rheumatoid arthritis patients who wanted to reduce the amount of pain medication they take.
"Every change in medication should be discussed with a GP but I would advise people to give cod liver oil a try for 12 weeks alongside their NSAIDs and then try to cut it down if they can manage it but if they don't manage it, that's fine.
"If you can get off NSAIDs it will be much safer."
National Rheumatoid Arthritis Society chief executive Ailsa Bosworth said: "People with rheumatoid arthritis still rely heavily on NSAIDs, even though the safety of these drugs is under scrutiny.
"We look forward to more research in this area."
British Society for Rheumatology president Dr Andrew Bamji said it was a small study so difficult to draw firm conclusions.
But he added: "Anything that can help to reduce NSAID use is going to be safer for patients.
"It does look as if the results are positive and that is quite interesting.
"I would say to patients by all means take cod liver oil and when you feel ready start to reduce your NSAID dose."
But he stressed that patients must discuss plans with their doctor because it was important that physicians were aware of all medications and supplements the patient was taking.