Benefits and Side Effects of Chondroitin for Osteoarthritis

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Chondroitin is a structural component of cartilage commonly used as a dietary supplement for osteoarthritis that shares a similar story with glucosamine. There’s a large heterogeneity in outcomes, with the industry-funded studies showing a benefit for symptomatic relief and the non-industry-funded studies showing no effect, with a small effect size similar to glucosamine. Considering just the largest, best-run studies, the benefit of chondroitin was found to be “minimal or nonexistent” and its use “therefore [should] be discouraged.”

Like glucosamine, the current American College of Rheumatology guidelines “strongly recommend against” the use of as chondroitin for knee or hip osteoarthritis, along with the American Academy of Orthopedic Surgeons and Osteoarthritis Research Society International, whereas the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases again allow for the use of pharmaceutical-grade, prescription-only chondroitin.

Chondroitin is typically extracted the animal cartilage—shark fins, bovine, and chicken windpipes, or pig noses—and slaughterhouse supply chains are not known for their “good manufacturing practices.” The lack of purity and presence of contaminants is blamed in part for the lack of consistent reproducibility. A study of 32 chondroitin supplements on the market found that only five contained the labeled amount, and some contained none. Terms like “quality tested” or retail price were found to provide no basis for judging quality. Some of the cheapest and the most expensive chondroitin on the market contained less than 10 percent actual chondroitin.

When the National Institutes of Health set out to design the esteemed GAIT trial, the Glucosamine/Chondroitin Arthritis Intervention Trial, they ruled out 20 different commercial products for issues like quality control before giving up and just deciding to have it specially made themselves. More than 1500 patients with symptomatic knee osteoarthritis were randomized to take standard daily doses of glucosamine, chondroitin, both glucosamine and chondroitin, an NSAID anti-inflammatory drug, or a placebo for six months. Only the drug beat out placebo for pain management. Neither glucosamine and chondroitin alone or in combination reduced pain effectively, and neither did they have any significant effect on delaying disease progression on x-ray. Chondroitin also failed in another two-year study, but two other trials found that by year two objective benefits could be found, and a third using more sensitive imaging (MRI) could pick up protective effects by six months. If you want to give it a try, there is now a purified non-animal source of chondroitin made from scratch that should be free from contaminants.

In the U.S., chondroitin and glucosamine are almost always sold in a combination pill. Like in the GAIT trial, a meta-analysis of studies pitting both against osteoarthritis found no clinically significant benefit. However, there had never been a trial in which pharmaceutical-grade, prescription-only preparations of both were used until finally one was published in 2017. The multicenter randomized, double-blind, placebo controlled clinical trial had to be stopped prematurely because one group was doing so much better than the other that it was deemed unethical to continue. See how much more one of treatments was reducing pain? But that superior treatment was the placebo! Unexpectedly, when the code was broken, it turned out that the placebo group did better! In other words, the industry-funded study found that their own pharmaceutical-grade chondroitin/glucosamine was making the pain significantly worse compared to a sugar pill. In the sugar pill group, 47 percent had at least a 50 percent improvement in pain or function, compared to just 28 percent in the chondroitin/glucosamine group. What the chondroitin/glucosamine users get was more side effects, such as diarrhea and abdominal pain; so, doctors may want to tell their patients to stop taking their glucosamine and chondroitin as it is less effective than placebo.

Motion graphics by Avo Media

Chondroitin is a structural component of cartilage commonly used as a dietary supplement for osteoarthritis that shares a similar story with glucosamine. There’s a large heterogeneity in outcomes, with the industry-funded studies showing a benefit for symptomatic relief and the non-industry-funded studies showing no effect, with a small effect size similar to glucosamine. Considering just the largest, best-run studies, the benefit of chondroitin was found to be “minimal or nonexistent” and its use “therefore [should] be discouraged.”

Like glucosamine, the current American College of Rheumatology guidelines “strongly recommend against” the use of as chondroitin for knee or hip osteoarthritis, along with the American Academy of Orthopedic Surgeons and Osteoarthritis Research Society International, whereas the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases again allow for the use of pharmaceutical-grade, prescription-only chondroitin.

Chondroitin is typically extracted the animal cartilage—shark fins, bovine, and chicken windpipes, or pig noses—and slaughterhouse supply chains are not known for their “good manufacturing practices.” The lack of purity and presence of contaminants is blamed in part for the lack of consistent reproducibility. A study of 32 chondroitin supplements on the market found that only five contained the labeled amount, and some contained none. Terms like “quality tested” or retail price were found to provide no basis for judging quality. Some of the cheapest and the most expensive chondroitin on the market contained less than 10 percent actual chondroitin.

When the National Institutes of Health set out to design the esteemed GAIT trial, the Glucosamine/Chondroitin Arthritis Intervention Trial, they ruled out 20 different commercial products for issues like quality control before giving up and just deciding to have it specially made themselves. More than 1500 patients with symptomatic knee osteoarthritis were randomized to take standard daily doses of glucosamine, chondroitin, both glucosamine and chondroitin, an NSAID anti-inflammatory drug, or a placebo for six months. Only the drug beat out placebo for pain management. Neither glucosamine and chondroitin alone or in combination reduced pain effectively, and neither did they have any significant effect on delaying disease progression on x-ray. Chondroitin also failed in another two-year study, but two other trials found that by year two objective benefits could be found, and a third using more sensitive imaging (MRI) could pick up protective effects by six months. If you want to give it a try, there is now a purified non-animal source of chondroitin made from scratch that should be free from contaminants.

In the U.S., chondroitin and glucosamine are almost always sold in a combination pill. Like in the GAIT trial, a meta-analysis of studies pitting both against osteoarthritis found no clinically significant benefit. However, there had never been a trial in which pharmaceutical-grade, prescription-only preparations of both were used until finally one was published in 2017. The multicenter randomized, double-blind, placebo controlled clinical trial had to be stopped prematurely because one group was doing so much better than the other that it was deemed unethical to continue. See how much more one of treatments was reducing pain? But that superior treatment was the placebo! Unexpectedly, when the code was broken, it turned out that the placebo group did better! In other words, the industry-funded study found that their own pharmaceutical-grade chondroitin/glucosamine was making the pain significantly worse compared to a sugar pill. In the sugar pill group, 47 percent had at least a 50 percent improvement in pain or function, compared to just 28 percent in the chondroitin/glucosamine group. What the chondroitin/glucosamine users get was more side effects, such as diarrhea and abdominal pain; so, doctors may want to tell their patients to stop taking their glucosamine and chondroitin as it is less effective than placebo.

Motion graphics by Avo Media

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