Arthritis is characterised by a collection of symptoms, which include inflammation, painful joints and stiffness. Rheumatoid arthritis is a chronic auto-immune disease that is extremely painful and can lead to severe disability. Osteoarthritis can be described as wear and tear of the joints with a resulting loss of cartilage.
Numerous studies have found that fish oil can improve the symptoms of rheumatoid arthritis by significantly reducing inflammation and in some cases, even lessen the need for NSAIDs (non-steroidal anti-inflammatory drugs). Similarly with osteoarthritis, studies have found that fish oil suppresses the action of cartilage destroying enzymes.
Fish oil contains the essential Omega 3 fatty acids (EFAs) that are found in high quantities in oily fish such as Salmon, Tuna, Sardines and Mackerel. They are essential in that the body cannot survive without them, yet cannot produce them itself; we can only source them from the diet. Most of us simply do not get enough of the Omega 3 fatty acids.
Traditionally, man ate a diet that was equally divided between Omega 3 and Omega 6 on an equal ratio of 1:1. Now, the ratio is more like 25:1 in favour of Omega 6. There is a substantial amount of research indicating that it is this imbalance of Omega 3′s to Omega 6 fats in our diets that are mainly responsible for the higher incidence of inflammatory diseases, cancers and allergies that we see today.
The Omega 6 fatty acids are also essential, but are easy to obtain, they can be found in cooking oils, such as corn oil and sunflower oil, and in processed foods and convenience foods. They promote inflammation in the body and help the blood to clot. The Omega 3′s do exactly the opposite; they have anti-inflammatory properties and help to thin the blood.
Clinical trials have reported that after taking fish oil for 12 weeks, patients found that their symptoms of arthritis improved, with less inflammation, pain and stiffness. Furthermore, those taking fish oil for longer than 12 weeks found they had an increase in grip strength.
As there is some evidence that Rheumatoid Arthritis is the result of oxidative stress on the body, and fish oil is very prone to oxidation, it is particularly important to choose a high quality fish oil containing a powerful antioxidant such as vitamin E.
Fish Oil and Arthritis Studies
David A Hughes and Andrew C Pinder were the principal researchers in the study titled n-3 Polyunsaturated fatty acids inhibit the antigen-presenting function of human monocytes. They conducted their research at the Institute of Food Research, Norwich Research Park, Colney, Norwich, and Norfolk. This research was published in December of 2004.
Researchers evaluated that diets rich in n-3 polyunsaturated fatty acids (PUFAs) are associated with suppression of cell-mediated immune responses, but the mechanisms are unclear. They hypothesized that n-3 PUFAs can inhibit the function of human antigen-presenting cells. A prerequisite for this role of blood monocytes is the cell surface expression of major histocompatibility complex (MHC) class II molecules [human leukocyte antigen (HLA)-DR, -DP, and -DQ], aided by the presence of intercellular adhesion molecule-1 (ICAM-1) and leukocyte function associated antigens 1 and 3.
It was shown previously that the n-3 PUFA eicosapentaenoic acid (EPA) inhibits the expression of HLA-DR on unstimulated human monocytes in vitro, but that docosahexaenoic acid (DHA) enhances its expression. However, both n-3 PUFAs suppress the expression of HLA-DR, HLA-DP, and ICAM-1 on interferon- -activated monocytes. They also established that dietary fish-oil supplementation can inhibit the expression of these surface molecules on circulating human monocytes.
We subsequently showed that when EPA and DHA were combined in the same ratio as is commonly found in fish-oil-supplement capsules (3:2), there was no significant effect in vitro on the expression of HLA-DR on unstimulated monocytes, but the expression on activated monocytes remained significantly inhibited. In the same in vitro system, the ability of activated monocytes to present antigen to autologous lymphocytes was significantly reduced after culture with the combined n-3 PUFAs.
These findings provide one potential mechanism for the beneficial effect of fish oil in the treatment of rheumatoid arthritis, a disorder associated with elevated _expression of MHC class II and adhesion molecules on monocytes present within affected joints.