Fish oil in knee osteoarthritis?

“Fish oil in knee osteoarthritis?” is an interesting question. I’ve already mentioned a study here on this blog:

Fish oil and knee OA

Poster #2147: Fish oil doesn't have an effect on structural progression of knee OA. They used 9 g, which would be 18 cps. in Germany.

29.10.2013

The researchers sit predominantly in the area of Adelaide (University of Adelaide) and I’ve been in contact with them. In different groups they research fish oil in rheumatoid arthritis and other diseases.

Now, they’ve published two year data on Fish oil in knee osteoarthritis (OA). 202 patients with knee OA were randomised 1:1 to high-dose fish oil (4.5 g omega-3 fatty acids) 15 ml/day or low-dose fish oil (blend of fish oil and sunola oil; ratio of 1:9, 0.45 g omega-3 fatty acids) 15 ml/day. “The primary endpoints were Western Ontario and McMaster Universities Arthritis Index (WOMAC) pain score at 3, 6, 12 and 24 months, and change in cartilage volume at 24 months. Secondary outcomes included WOMAC function, quality of life, analgesic and non-steroidal anti-inflammatory drug use and bone marrow lesion score.” Results: “…the low-dose fish oil group had greater improvement in WOMAC pain and function scores at 2 years compared with the high-dose group …” Other endpoints didn’t reach statistical significance. The authors concluded: “In people with symptomatic knee OA, there was no additional benefit of a high-dose fish oil compared with low-dose fish oil. The combination comparator oil appeared to have better efficacy in reducing pain at 2 years, suggesting that this requires further investigation.”

Maybe, maybe not. The study didn’t have a placebo arm. Maybe omega-3 fatty acids like in fish, fish oil or flax oil will have a place in the treatment of rheumatoid arthritis or other auto-inflammatory diseases, but knee osteoarthritis might not benefit. However, I don’t want to sound too apodictical – please go on with your research.

References:

http://rheumatologe.blogspot.de/2013/10/acr-meeting-2013-in-san-diego.html

CL Hill et al.: Fish oil in knee osteoarthritis: a randomised clinical trial of low dose versus high dose. Ann Rheum Dis. 2016 Jan;75(1):23-9. doi: 10.1136/annrheumdis-2014-207169. http://www.ncbi.nlm.nih.gov/pubmed/26353789

Rheumatoid Arthritis and Omega 3 Fatty Acids

There has been a study on rheumatoid arthritis and omega-3 fatty acids recently. D. di Giuseppe and colleagues published: “Long-term intake of dietary long-chain n-3 polyunsaturated fatty acids and risk of rheumatoid arthritis: a prospective cohort study of women.” The authors collected data on diet via a self-administered food-frequency questionnaire in 1987 and 1997. “Among 32 232 women born 1914-1948, 205 RA cases were identified during a mean follow-up of 7.5 years (1 January 2003 to 31 December 2010; 2 41 120 person-years).” They concluded: “This prospective study of women supports the hypothesis that dietary intake of long-chain n-3 PUFAs may play a role in aetiology of RA.” Link: http://www.ncbi.nlm.nih.gov/pubmed/23940215.

Some people already think that we all have to take fish oil supplementation to avoid getting rheumatoid arthritis. I think that most of the population need more omega-3 fatty acids, but I don’t think that we need supplementation. Y.H. Lee and colleagues published a meta-analysis in 2012: “Omega-3 polyunsaturated fatty acids and the treatment of rheumatoid arthritis: a meta-analysis.” At ≥2.7 g omega-3 polyunsaturated fatty acids per day there has been reduced nonsteroidal anti-inflammatory drug (NSAID) consumption over the 10 RCTs. Tender joint, swollen joint count, morning stiffness, and physical function only showed a trend but did not reach statistical significance. Link: http://www.ncbi.nlm.nih.gov/pubmed/22835600.

So what can one do? Reduce omega-6 fatty acids and increase omega-3 fatty acids. I don’t think that fish or krill oil is necessary. If you eat fish, prefer fish to meat (meat is bad anyway). If you live the happy vegetarian life watch out to significantly reduce omega-6 fatty acids (especially if you’re going vegan) and use more oils and seeds containing omega-3 fatty acids, linseed contains the most.