Osteoarthritis is the most common form of arthritis, and can affect the hands, hips, shoulders and knees. It tends to develop when the cartilage that protects the ends of the bones breaks down and causes pain, swelling and inflammation. Rheumatoid arthritis, in contrast, is an autoimmune disease of the joints, which results in chronic inflammation. Both conditions affect flexibility and mobility and can be extremely debilitating for the sufferer. Approximately 1 in 5 people in the UK are affected.
Currently, the standard pharmaceutical method for treating arthritis is through the use of non-steroidal anti-inflammatory drugs (NSAIDs), which many of the millions of arthritis sufferers are reliant upon in order to function on a day-to-day basis. Whilst they do bring temporary relief, they are also associated with many side effects including nausea, vomiting, bowel problems dizziness and headaches. Long-term use can bring more serious effects , such as gastrointestinal toxicity, increased blood pressure, and increased risk of heart attack. It is not surprising, therefore, that sufferers are keen to seek reliable alternatives. A common (and very effective) non-pharmaceutical option for treating arthritis is through supplementation with glucosamine.
Glucosamine is a key player in the synthesis of glycoproteins, glycolipids and glycosaminoglycans – components which are the core materials used by the body to make cartilage, as well as synovial fluid and other elements of the skeletal system. Supplementing with glucosamine stimulates the production of these compounds, resulting in cartilage replacement and pain reduction. The benefits of glucosamine are not, however, confined to replenishment of essential compounds, but also include anti-inflammatory benefits 
More recently, research has shown that combining glucosamine with omega-3 fish oils may be more effective for arthritis sufferers than simply supplementing with glucosamine alone. The health benefits of omega-3s for the cardiovascular system are well established, and part of the reason for this is due to their anti-inflammatory and anti-arrhythmic actions. One specific omega-3 called eicosapentaenoic acid (EPA) not only gives rise to its own family of anti-inflammatory products, but also suppresses the production of other inflammatory mediators. In fact, EPA works in exactly the same way as NSAIDs, by suppressing the actions of an enzyme called COX-2 (hence NSAIDs are also commonly known as COX inhibitors). NSAIDs aren’t the answer, however, because they also suppress the activity of another enzyme – known as a “house-keeping” enzyme or COX-1 – which regulates cardiovascular and gut function. Because these drugs interfere with this important pathway they also interfere with gut and cardiovascular function (hence the side effects previously mentioned), with stomach ulcers and heart problems posing a major issue in their use.
In contrast, however, EPA is selective and only targets COX-2, leaving COX-1 to function normally. The good news is that EPA omega-3, therefore, does not come with any unwanted side effects.
In a randomized, double-blind, comparison study of 177 patients with moderate-to-severe hip or knee osteoarthritis, omega-3 fish oils combined with 200mg omega-3 and 1500mg glucosamine was found to reduce symptoms such as morning stiffness, and pain in the hips and knees more significantly over a period of 26 weeks than taking glucosamine alone. Furthermore, the researchers reported that both products are safe as a long-term treatment option. 
The synergistic action of EPA omega-3 fish oil and glucosamine is particularly effective in arthritis, due to the anti-inflammatory properties offered by omega-3 EPA with a subsequent replacement of vital components by glucosamine. This is good news for arthritis patients, given the over-prescription of NSAIDs, for whom the unwanted side effects of which may eventually be a thing of a the past.
 Hong H, Park YK, Choi MS, Ryu NH, Song DK, Suh SI, Nam KY, Park GY, Jang BC.
Differential down-regulation of COX-2 and MMP-13 in human skin fibroblasts by glucosamine-hydrochloride. J Dermatol Sci. 2009 56:43-50.
 Gruenwald J, Petzold E, Busch R, Petzold HP, Graubaum HJ. Effect of glucosamine sulfate with or without omega-3 fatty acids in patients with osteoarthritis. Adv Ther. 2009 26:858-71. Epub 2009 Sep 4.