Osteoarthritis is a degenerative form of arthritis.
It can affect any joint but mostly affects knees, lower back, hips, and joints of fingers.
Cartilage is a soft bone tissue present at the end of every bone and it serves as a smooth surface over which joints move easily.
In osteoarthritis, the cartilage begins to break down leading to pain and inflammation.
Even the fluid that lubricates the joints for easier movement experiences inflammation.
The bone starts degrading and bits of bone and cartilage start floating around the joint triggering pain and inflammation.
Eventually, the cartilage wears causing friction and pain in joint movement.
Major symptoms include joint pain, swelling, inflammation, difficulty in moving joints. Previous joint injury, age, obesity, and certain inherited conditions can predispose you to this condition.
Treatment involves lifestyle changes, exercise, and medications. Medications include painkillers, opiods, and non-steroidal anti-inflammatory drugs. Supplements for bone health are also prescribed.
Two such bone protective agents are chondroitin and glucosamine and this article focuses on the effectiveness of glucosamine and chondroitin in osteoarthritis.
What are Chondroitin and Glucosamine?
Chondroitin is a molecule that is naturally present in cartilage. It is a structural component of cartilage and prevents the cartilage from compressing.
Chondroitin blocks enzymes that would break down cartilage and serves as a building block of cartilage.
It is either derived from shark or bovine cartilage or produced synthetically. Chondroitin is commonly sold as chondroitin sulphate in the form of capsules or tablets.
Glucosamine is also produced naturally in the body and is essential for the formation of cartilage.
It is part of the exoskeletons of crustaceans such as crabs and lobsters.
Glucosamine is generally available as glucosamine sulphate, glucosamine hydrochloride, and N-acetylglucosamine.
Glucosamine and chondroitin are dietary supplements that are taken in combination for the treatment of osteoarthritis.
Together they are said to reduce cartilage degradation and hence slow down the progression of osteoarthritis.
6 Benefits of Chondroitin and Glucosamine In Osteoarthritis
As chondroitin and glucosamine are a part of natural cartilage, they serve as bone protective agents.
They have certain pharmacological properties that make them beneficial in the treatment of osteoarthritis.
1. They act as anti-inflammatory agents
Osteoarthritis is characterised by inflammation of the joint tissue which further accelerates the degradation of the bone. Chondroitin sulphate has anti-inflammatory activity.
It inhibits the activity of inflammatory mediators such as COX enzyme, prostaglandins, nitric oxide synthase.
It is proven to act on inflammatory biochemical pathways and inhibit the activity of inflammatory regulators such as tumor necrosis factor and nuclear factor kappa B.
In the animal model of arthritis, chondroitin sulphate is found to reduce synovitis or inflammation of synovial membrane that lubricates the joint.
Similarly glucosamine modulates its anti-inflammatory activity by regulating function of nuclear factor kappa B- a protein that controls inflammatory process. N-acetylglucosamine is found to control inflammation in collagen induced arthritis.
What does this mean? Both chondroitin and glucosamine exert anti-inflammatory property and reduce production of inflammatory mediators in osteoarthritis.
2. They serve as antioxidants
Oxidative stress causes extensive damage in osteoarthritis. It is the imbalance between prooxidants and antioxidants in the body.
This oxidative stress creates free radical species which cause synovial membrane damage, inflammation, and cell death.
Chondroitin sulphate is proven to work as an antioxidant in an animal model of collagen-induced arthritis.
It protects from damaging harmful molecules like hydrogen peroxide, free radical species and improves antioxidant defences by raising the level of antioxidant enzymes.
Glucosamine antioxidant property is found to be effective in reducing cartilage degradation.
Chondrocytes produce nitric oxide which contributes to oxidative damage in osteoarthritis.
Glucosamine, as an antioxidant, protects from nitric oxide induced damage in osteoarthritis.
What does this mean? Glucosamine and chondroitin serve as antioxidants and reduce oxidative damage in osteoarthritis.
3. They have chondroprotective effect
Chondroitin sulphate has an anti-apoptotic effect: it prevents cell death of chondrocytes (a type of bone cell).
It reduces the activity of various proteins and enzymes such as caspases which are involved in cell death.
Chondroitin sulphate also reduces bone resorption and prevents cartilage degradation.
Similarly, glucosamine also exerts chondroprotective effects by regulating the activity of proteins such as p38 and nuclear factor-kappaB that are involved in cell death and proliferation.
Animal studies prove that chondroitin and glucosamine sulphate combination work as chondroprotective agent.
What does this mean? Chondrocytes are type of bone cells that are damaged in osteoarthritis and glucosamine as well as chondroitin work as chondroprotective agents.
4. Chondroitin supplementation reduces pain and bone loss in osteoarthritis
Singh et. al reviewed 43 clinical trials involving the use of chondroitin for osteoarthritis.
A significant reduction in pain and improvement in structural changes of joint was reported and also side effects caused by chondroitin was less.
Other review studies show that chondroitin supplementation can reduce dependence on non-steroidal anti-inflammatory drugs.
A clinical trial was conducted to compare the effect of chondroitin and diclofenac sodium on pain in osteoarthritis.
It was observed that those treated with painkillers experienced quick relief but the symptoms reappeared after treatment.
However, in the group treated with chondroitin there was a delay in therapeutic response but the effect lasted 3 months after treatment.
Chondroitin sulphate at 1g per day is found to be beneficial in the treatment of knee osteoarthritis in terms of reducing pain, improving joint function and quality of life as well as reducing dependence on painkillers.
Chondroitin sulphate is prepared from two sources: avian and bovine. A study was done to assess the effect of each of these chondroitin sulphate preparations on knee osteoarthritis.
Structum (500mg twice a day) and Chondrosulf (400 mg thrice a day) was provided for 24 weeks. Reduction in pain score was similar in both groups.
It was concluded that both Structum and Chondrosulf are equally effective in reducing pain and improving joint function with no safety concerns.
Railhac et. al have proven that chondroitin supplementation not only treats symptoms of osteoarthritis but also increases cartilage volume.
These findings are confirmed by another study which also shows that chondroitin reduces cartilage loss and number of bone marrow lesions in osteoarthritis.
What does this mean? Chondroitin supplementation reduces pain, reduces cartilage loss, improves joint function and reduces the requirement of painkillers in osteoarthritis.
5. Glucosamine supplementation reduces pain in osteoarthritis
A review by Black et. al reported that glucosamine sulphate reduced the need for knee arthroplasty (surgical treatment for knee osteoarthritis) from 14.3% to 6.3% during 8 years follow up.
A clinical trial was conducted where the effect of glucosamine supplementation was compared to ibuprofen in jaw osteoarthritis.
60 patients were enrolled, 30 were treated with 400mg ibuprofen twice a day and the other 30 were treated with 1500mg glucosamine. The study lasted for 90 days.
Reduction in pain and improvement in jaw opening was observed in both groups but a more significant improvement was seen in glucosamine group and side effects were lower in glucosamine group.
Houpt et. al conducted a study assessing the effect of glucosamine sulphate on knee osteoarthritis. Patients were given paracetamol and glucosamine or placebo.
Over 8 weeks the pain score and the use of painkillers were observed.
49% of the individuals taking glucosamine experienced a decrease in pain.
Not much difference in pain was observed in placebo and glucosamine groups but overall researchers concluded that in terms of secondary endpoints glucosamine had benefits for osteoarthritis.
A similar comparison was conducted by Beaumont et. al and it was found that number of responders was higher in the group taking glucosamine than paracetmol and placebo.
A 12-week study showed that glucosamine supplementation (1500mg a day) for 12 weeks brought about a significant improvement in knee osteoarthritis, significant reduction in resting pain and reduced use of painkillers.
Glucosamine is suggested as a long term therapy for osteoarthritis since it reduces symptoms of osteoarthritis as well as produces structural changes in joints.
What does this mean? Various clinical trials show that glucosamine acts in a similar fashion as chondroitin and benefits in osteoarthritis by reducing pain and improving joint structure.
6. Chondroitin and glucosamine combination reduces the progression of osteoarthritis
Chondroitin and glucosamine are identified as disease-modifying osteoarthritis drugs; they produce structural improvements in joints, reduce pain and slow down progression of osteoarthritis.
The LEGS study demonstrated that glucosamine sulphate (1500mg) and chondroitin sulphate (800mg) taken daily for a period of 2 years showed a significant structural change in the joint but no significant improvement in pain compared to placebo was observed.
Zeng et. al have proven that chondroitin and glucosamine combination is as effective as celecoxib, a non-steroidal anti-inflammatory drug in reducing pain in knee osteoarthritis.
The combination was more effective in improving joint function and producing structural changes in joint. Also, the combination caused lesser side effects than celecoxib.
Another 6-month study also proved that chondroitin sulphate and glucosamine hydrochloride combination is as effective as celecoxib in reducing pain and swelling in osteoarthritis.
The most important clinical trial conducted on the efficacy of chondroitin sulphate and glucosamine is the GAIT trial.
The dose was 400mg of chondroitin sulphate 3 times a day, 500mg of glucosamine 3 times a day, the combination, celecoxib 200 mg or placebo.
Celecoxib was found to be most effective in reducing pain followed by glucosamine and then the combination. Researchers concluded that neither treatment showed any clinically significant effect.
A study was conducted to investigate the effect of the combination of chondroitin and glucosamine on painkiller dependence.
The combination was found to reduce intake of painkillers by 6.8% in 1 month and 37.3% in 3 months.
Provenza et. al studied the effects of high dose and low dose of chondroitin and glucosamine on knee osteoarthritis.
This study involved 1120 patients. Significant improvement in pain was observed in all groups.
This study involved a large study group and therefore results are genuine and clinically significant. Researchers concluded that the combination can produce a significant reduction in pain in knee osteoarthritis.
What does this mean? A large number of clinical trials have been dedicated to proving efficacy of the combination of glucosamine and chondroitin in osteoarthritis. The combination is found to be as effective or even better than non steroidal anti-inflammatory drugs in reducing pain in osteoarthritis.
Dosage
Chondroitin sulphate and glucosamine are available as capsules or tablets that are to be taken as dietary supplements for osteoarthritis.
The dosage for chondroitin sulphate is 400mg 3 times a day or 600mg twice a day. The recommended dose of glucosamine is 400-500mg thrice a day.
Precautions
Generally, no side effects are reported with chondroitin but some may experience mild stomach upset, drowsiness, allergic reactions, headaches, etc.
Certain conditions in which chondroitin sulphate should be taken with caution are:
- Pregnancy and lactation
- Asthma
- Prostate cancer
- Bleeding disorder
- Diabetes
Chondroitin could have drug interactions with blood thinning agents and non-steroidal anti-inflammatory drugs.
Glucosamine cause minor side effects such as gastric symptoms. It is advisable that glucosamine should be taken with food.
Those suffering from diabetes, cholesterol problems or consuming potassium-sparing diurectics should take glucosamine with caution.
Pregnant and breastfeeding women should avoid glucosamine supplements.
Those with shellfish allergy should not take glucosamine supplements.
Glucosamine could have drug interactions with blood thinning agents, non-steroidal anti-inflammatory drugs, cancer medications and blood sugar-lowering agents.
Conclusion
Chondroitin and glucosamine are natural components of bone tissue and cartilage. They benefit in osteoarthritis by acting as anti-inflammatory agents and antioxidants.
Additionally, they protect bone tissue and prevent bone resorption and prevent degrading enzymes from damaging bone tissue.
Quite a large number of clinical trials have been conducted to study the effect of glucosamine and chondroitin supplementation in osteoarthritis.
Chondroitin and glucosamine have found to be effective in reducing osteoarthritis pain and improves joint structure and function.
They are slow acting drugs and gradually can reduce dependence on painkillers in osteoarthritis.