Introduction

Osteoarthritis is the most common type of arthritis, affecting mainly older people. Treatment for osteoarthritis focuses on managing symptoms through lifestyle changes, physical therapy and medication. Glucosamine and turmeric are often mentioned as an alternative treatment for osteoarthritis, but the evidence is mixed. What exactly does the evidence say, and how do we use that to make decisions about our healthcare?

What is osteoarthritis?

Osteoarthritis is a degenerative joint disease, which causes joints to become painful and stiff. It is the most common type of arthritis¹ and affects mainly older people. Osteoarthritis most commonly affects the joints of the knees, hips, spine and hands. The exact cause of osteoarthritis is not known but there are certain factors that can contribute to developing the condition, including previous joint injury, overuse, older age and being overweight.²

What happens to your joints in osteoarthritis?

As osteoarthritis develops, it damages all parts of the joints, including the cartilage, tendons and ligaments and the bone. Eventually, small bits of bone start to grow on the edge of the joint called osteophytes and the joint itself can start to change shape. Small bits of bone or cartilage can break off and float around inside the joint, causing clicking and locking. 

What are the symptoms of osteoarthritis?

Symptoms of osteoarthritis vary considerably, with some people experiencing only mild symptoms that come and go, whilst others can suffer from severe, often debilitating pain. The most common symptoms include joint pain and stiffness. The stiffness is often worse first thing in the morning, or after a period of inactivity, but usually lasts less than 30 minutes.¹ Sufferers may also experience swelling around the joint, or feelings of instability or weakness. 

How is osteoarthritis normally treated?

There is currently no cure for osteoarthritis and treatment instead focuses on managing symptoms. Your medical professional will choose the appropriate treatment based on the severity and duration of symptoms. 

Lifestyle changes

• Physical activity - has been shown to be highly effective in helping to reduce pain and improve mobility in sufferers of osteoarthritis.³ In particular, low to medium-intensity aerobic exercise, such as walking, cycling and swimming seem to be particularly beneficial, as well as targeted strength training around the affected joint⁴ 
• Mobility aids - such as braces and walking sticks, can help to reduce pain and keep you moving.⁵ They are particularly useful to help sufferers of OA carry out normal daily tasks, such as going shopping or walking the dog. TENS machines can also help with pain relief⁵ 
• Weight Management - is recommended for the treatment of osteoarthritis as losing weight reduces the load put on your joints⁶
• Physical Therapy - This is a hands-on treatment by physiotherapists or other manual therapy practitioners, involving massage, joint mobilisations and exercises. It is recognised as a safe and effective treatment for OA⁷

Medication 

Medication can be given to help manage the symptoms of osteoarthritis. It is often recommended in conjunction with other treatments, such as physical activity, weight loss and physical therapy. Medications given can include paracetamol, non-steroidal anti-inflammatory drugs (NSAID) and opioids. Capsaicin cream which you rub on the affected area can also help to manage pain. Steroid injections can also be used to relieve pain in joints from osteoarthritis. 

Surgery

In severe cases of osteoarthritis, when conservative options have been exhausted, joint replacement surgery may be available. This is where your arthritic joint is removed and an artificial joint, made of plastic, or metal is inserted instead. Surgery for osteoarthritis is more readily available for some joints than others, such as hips and knees. 

Turmeric and glucosamine in osteoarthritis management

What is turmeric?

Turmeric is a spice you may recognise from Indian-Asian cooking. One of the active components within turmeric is curcumin, which makes up about 3% to 10% of the turmeric powder.⁸ It is thought that curcumin has anti-inflammatory properties similar to that of non-steroidal anti-inflammatories by interrupting the signals of pro-inflammatory proteins in the body, and by inhibiting other enzymes that are involved in the breakdown of cartilage.⁹

How effective is turmeric in the treatment of osteoarthritis?

There are indications that curcumin, the active ingredient in turmeric, may be beneficial in the treatment of osteoarthritis.^9,10,11 The evidence appears to show that curcumin may provide benefits similar to that of NSAIDs, such as diclofenac and ibuprofen.¹⁰ Despite positive indications, recommendations for the use of turmeric are still tentative. Much of the evidence has only been conducted over a fairly short-term basis (8 months max),⁹ so its longer-term effects are still unknown. A large proportion of the research focuses on knee arthritis, and other variables such as weight loss and physical therapy are often not accounted for.  

Safety of turmeric

Supplementing with curcumin is also considered to be very safe, with almost negligible side effects.¹⁰

What is glucosamine?

Glucosamine is a building block for molecules called glycosaminoglycans, a natural substance found in cartilage that helps to cushion your joints. It can also be taken as a dietary supplement, often in combination with other supplements, such as chondroitin.  Whilst the mechanism of action is not thoroughly understood, it is thought that supplementing glucosamine may help to rebuild cartilage, thereby slowing the progression of osteoarthritis.¹²

How effective is glucosamine in the treatment of osteoarthritis?

Glucosamine supplements as a treatment for osteoarthritis have been extensively studied. 

Several studies have shown some improvements in both pain and function following a course of glucosamine.^13,14 This includes systematic reviews and meta-analyses which are considered to be gold-standard research studies¹⁵, as they take into account all relevant studies on the topic. However, other studies have been unable to find any benefit for glucosamine over a placebo supplement. A Cochrane review, which attempts to bring together all the evidence about glucosamine, concludes that, if only high-quality studies are included, there is no benefit to pain or function for taking glucosamine for osteoarthritis.¹⁶ As a result, the use of glucosamine remains controversial.

Safety of glucosamine 

Although the effectiveness of glucosamine remains undecided, overall the consensus indicates that glucosamine is safe to take as a supplement.¹⁶ There have been suggestions that glucosamine intake may contribute to the development of hardening of the arteries¹⁷ (atherosclerosis) and asthma exacerbation¹⁸, no further evidence has supported these claims.  

How do we bridge the gap between this data and decision-making in healthcare?

For many, the evidence surrounding glucosamine and turmeric supplementation may still seem a confusing picture. For glucosamine in particular, there are many different trials which all seem to come to different conclusions: some suggest glucosamine is an effective treatment for OA, whilst others negate this fact. Assimilating this data and using it to inform decision-making is a difficult task for both medical providers and the general public. So how do we go about making these decisions?

Firstly, when presented with data on a subject, it is important to scrutinize where that information is coming from and how it has been obtained. For example, there are many different types of clinical trials, and some should be considered to be more reliable than others. Overall, Randomized controlled trials (RCTs) are believed to be the most reliable study type¹⁹, as patients are randomly assigned to either a treatment group or a control group. However, reading individual studies can be challenging, and only gives you one viewpoint. Systematic reviews amalgamate results from all of the good-quality studies available, giving you one overall summary of the treatment effect. Cochrane reviews, systematic reviews that are carried out by Cochrane collaboration, are widely recognised as the highest standard in healthcare research. Systematic reviews carried out by Cochrane Collaboration (an international network of researchers belonging to this independent, not-for-profit organization) are recognized worldwide as the highest standard in evidence-based healthcare²⁰. There are a number of studies which show glucosamine has a beneficial effect on the symptoms of osteoarthritis; however, the Cochrane review which assimilates the high-quality studies on the topic, concludes there is no evidence of any benefit of glucosamine on osteoarthritis.¹⁶ Increased discernment is needed when looking at the data on turmeric. Whilst there are RCTs and systematic reviews that indicate turmeric supplements have a beneficial effect on osteoarthritis, the Cochrane review is yet to be published. 

Whilst studies offer important data into the effectiveness of different treatments, it is also important to remember they are primarily concerned with clinical results: how treatments perform under very strictly controlled conditions, not in the real world. They also do not take into account patient’s values and preferences, or health care resources.¹⁹ As such, clinical guidelines such as the NICE guidelines which the NHS adheres to can help both patients and clinicians to decide on the best course of action. Finally, patient preferences must also be considered an important part of decision-making in healthcare. For example, some patients may prefer to trial the use of glucosamine and turmeric in managing their osteoarthritis symptoms, with the knowledge that the evidence supporting both of them is tentative at best. 

Summary

The evidence over turmeric and glucosamine is mixed but, overall, glucosamine does not appear to have any benefit on osteoarthritis. By contrast, the evidence tentatively suggests that turmeric has a positive effect on osteoarthritis, almost equal to that of NSAIDs. However, further reviews of the evidence are still to be conducted.