Chondroitin (or chondroitin sulphate) is one of the more popular joint health supplements seen on the market today. In fact, it is is a naturally occurring substance which can be found in articular cartilage and in the synovial fluid sitting in our joint spaces (1). This article will examine whether the claims made about chondroitin in helping us stave off arthritis and joint injury are true, or whether chondroitin fails to live up to the hype.
What is Chondroitin?
Chondroitin is actually a naturally occurring carbohydrate molecule called a glycosaminoglycan, which is made up of alternating uronic sugar (d-glucuronic acid) and amino sugar (N-acetyl-D-galactosamine) molecules. It is also an essential component of our extra-cellular matrix, which surrounds our cells to give structure and transport of important chemicals.
Within our cartilage, chondroitin is the most frequently found glycosaminoglycan in the aggrecan (or cartilage-specific proteoglycan core protein) which is an important part of cartilage to give it structure and aid function of the joints. It is predominantly responsible for retaining water in the cartilage which assists resistance of forces through this tissue (1).
Why is Chondroitin used?
Despite chondroitin being a naturally occurring component of our bodies tissues, supplementation of this compound can be beneficial when there is an imbalance of cellular processes of cartilage from anabolism (cell making) to catabolism (cell breakdown). The most common circumstance of such an imbalance would be in osteoarthritis, where cartilage cells are destroyed and chondrocytes can no longer manage the loss of collagen and connective tissue (proteoglycan) cells- even when increasing the rate of cell synthesis (2).
Due to its effect on cell breakdown, chondroitin sulphate has been labelled both a symptomatic slow-acting drug for osteoarthritis and a structure-modifying drug in osteoarthritis, aiming to slow progression of the disease (3). It has a number of mechanisms in its ability to modify the course of arthritis which includes improving the viscosity of synovial fluid in our joints through elevating hyaluronic acid production by synovial cells; stimulation of chondrocyte metabolism to boost collagen and proteoglycan synthesis to make more cartilage; and inhibition of catabolic enzymes which break down cartilage (4).
In essence, by targeting the processes which cause cartilage cell destruction and anabolic processes which stimulate more tissue production, chondroitin can re-balance the cartilage levels in our joints.
What are the benefits of Chondroitin?
A number of high-quality studies have highlighted the apparent positive effects of this supplement on joint health. One such comprehensive review (5) examined 39 other clinical studies or meta-analyses and concluded that chondroitin has a significant positive effect on osteoarthritis.
The benefits of chondroitin vary to include improvements in patient reported symptoms, such as reduction in levels of pain and inflammation (4). In fact, despite the reticence of the National Institute of Clinical Health & Care Excellence to recommend chondroitin in its osteoarthritis guidelines (6); they do highlight the effect of chondroitin in reducing measures of pain as much as non-steroidal anti-inflammatory medications (e.g. ibuprofen) (7). In fact, they also show that this pain relieving effect occurs with more withdrawals from the study by people complaining of adverse effect, compared to those who were given anti-inflammatories.
The benefits of chondroitin consumption, however, do not stop there, as studies also show that this supplement also improves functional outcomes related to walking mobility and even a reduction in analgesia use (8). In fact following supplementation with chondroitin overall mobility capacity (the amount of walking possible before being inhibited by pain) was increased by 69% (which was 50% more than a placebo supplement (9).
Other measures better demonstrate the influence of chondroitin’s protective effects on joint health. For example, the radiological examination is often used to assess the degree of osteoarthritic change in a person’s joints. A number of studies have shown that taking chondroitin has the effect of preserving joint space appearances on x-ray (10-11) in essence showing that osteoarthritic loss of joint space on radiograph has been prevented. This benefit of delaying osteoarthritis disease progression has also been found in similar studies (8-9,12).
Even in outlying studies which report that any benefit of chondroitin on pain relief was no different than that seen with placebo (7); there was still evidence that chondroitin still has an effect on reducing joint swelling!
A number of studies demonstrate that the benefit of chondroitin is enhanced when consumed alongside another supplement, glucosamine sulphate (13-17). It is thought that this combination of compounds provides inhibition of the production of several biochemical which cause cartilage destruction (18).
The most recent and comprehensive review of the scientific literature pertaining to chondroitin was undertaken and published in 2015 by the Cochrane Library (19). They examined the findings of 43 randomised controlled trials which collectively had used 4,962 individuals and compared the effects of chondroitin on osteoarthritis compared to placebo. Their conclusions found that chondroitin alone (or in conjunction with glucosamine) was better than placebo in reducing pain and function to a level which is likely to be clinically meaningful.
Recommendations: Safety and Dosage
In clinical trials the highest dosage of chondroitin used is 1200mg per day (20), and all evidence points to the fact that there is no adverse effect related to consumption at this level. This is mostly supported by two specific trials.
One of these trials (21) took a group of 165 people with arthritis and provided them with an oral dose of 1200mg every day for THREE YEARS! During this three year period they were independently monitored by three different doctors, and at the end of the study, the only adverse event reported was one case of gastritis. In fact, the placebo group in the study suffered more people withdrawing than the chondroitin group did!
The results are subsequently supported by another trial (7) which took an even larger group of 1500 people with arthritis and provided 1200mg of chondroitin per day alone or in combination with 1500mg of glucosamine chloride for a period of 24 weeks. A total of 635 people were given chondroitin alone or with glucosamine and the trial found no clinical adverse effects on blood and urine biochemistry following its consumption.
Due to these facts, a maximal dose of 1200mg per day is suggested. It is generally accepted that if you are suffering from arthritis, then twice yearly a course of 800mg of chondroitin daily for a period of 3 months, supports the use of this supplement to attenuate your symptoms and decrease the progression of the disease.
Take Home Message
The degenerative change which occurs with arthritis is very common and is often asymptomatic (22-23). However, when pain is present and symptoms take hold the disease can be debilitating to daily life. Alongside sustaining a good nutritional balance and a level of physical activity, supplements such as chondroitin can be useful agents to improve your joint health.
In fact they may do so as well as other medications, which may also lead to side effects. If you have joint pains or have concerns that you have arthritis, consider chatting to your GP or a physiotherapist; but also take control back and try chondroitin to see if you gain some benefit.