Consumers report adverse reactions
Glucosamine, a dietary supplement that has been touted as being able to do everything from rebuild cartilage to helping to cure arthritis, is one of the most popular non-vitamin over-the-counter supplements in the U.S. with sales topping $700 million. But the benefits of glucosamine are in dispute.
Glucosamine became popular in the U.S. in the 1990s. An amino acid that is produced commercially from the exoskeletons of crustaceans, it is often coupled with chondroitin in supplements.
Sales of the supplement grew quickly in the mid-1990s when it was hailed in Dr. Jason Theodosakis’ book, “The Arthritis Cure.” The 1996 book cited then-promising studies that found glucosamine stimulated the production of cartilage, helped reduce pain and improved joint function in some patients.
Marketers seized on the claims, touting glucosamine products to consumers eager for relief from joint pain and stiffness.
But not all doctors were on board with this supplement as a cure-all for joint problems.
Theodosakis said glucosamine — which he sells in supplement form on his website — was meeting with resistance from U.S. doctors “because they don’t know any better” and later, in a 2013 interview with Dr. Oz
, discussed with him about how it was becoming the Darth Vader of supplements. But doctors may have had good reason to be hesitant to embrace the supplement.
In February 2004, the American Journal of Orthopedics published an article saying that cartilage could not be regenerated because blood doesn’t flow to the damage cartilage, thus preventing any mechanism to rebuild it.
The 2006 study published in the New England Journal of Medicine found that while a small subgroup of patients with moderate to severe pain showed some relief, there was no evidence glucosamine and chondroitin were effective in relieving the symptoms of osteoarthritis. Other studies confirmed similar findings:
A 2008 study
also sponsored by the National Institutes of Health published in the Journal Arthritis and Rheumatism that followed up on the 2006 study found that the supplements were no more effective at preventing joint damage caused by arthritis than a placebo.
Now the industry is facing a slew of lawsuits
taking aim at a variety of marketing claims made by manufacturers and major retailers, such as Wal-Mart, in the packaging and advertising of glucosamine supplements. The challenged claims include:
Protect and rebuild cartilage tissue
• Improve joint health
• Lubricate joints
• Improve joint mobility and flexibility
• Reduce joint pain
Several of the lawsuits also criticized the earlier studies touted by the industry as heavily flawed, noting that some were sponsored by glucosamine manufacturers. (Some of the lawsuits have reached multi-million settlements. See related story here
on TINA.org’s efforts on one such settlement.)
In addition to the lawsuits, some experts started advising against taking the supplement. In 2013, the American Academy of Orthopaedic Surgeons announced
it was recommending patients who suffer from osteoarthritis of the knee not take glucosamine.
Warnings to companies
Dietary supplements do not receive the same oversight as drugs by the FDA. But the agency was clear back in 2004 about claims it said a glucosamine supplement marketer should not make. Back then, the agency rejected a request
by Arizona-based Weider Nutrition International to make claims its glucosamine product could reduce the risk of osteoarthritis and osteoarthritis-related joint pain and degeneration, finding that scientific evidence to date wasn’t sufficient to back up the claims and that many of the studies the company cited were seriously flawed.
The agency in subsequent years also sent warning letters
to dozens of manufacturers and marketers of glucosamine products with quality control issues and for making treatment claims — such as “rebuild healthy cartilage” and “soothe joints while helping the rebuilding process” — that made them unapproved drugs. But those were just a few of a number of marketers making similar claims who continued to flood the market with glucosamine products.
Is it safe?
According to documents obtained by TINA.org through a Freedom of Information request, the FDA has also received more than 200 adverse events reports
reported by consumers taking glucosamine products to dietary supplement manufacturers. The reports cite a variety of reactions including everything from abdominal pain to atrial fibrillation to a death.
FDA spokeswoman Jennifer Dooren said that it is often difficult for the FDA to fully evaluate whether the product caused the adverse event or simply coincided with it. Some reports are missing information such as other supplements or drugs a person may have been taking along with glucosamine and the condition of their overall health.
“The fact that an adverse event happened after a person took a dietary supplement does not necessarily mean that the dietary supplement caused the adverse event,’’ she said in an email to TINA.org. “… If we find a relationship between the consumption of the product and harm, FDA will take appropriate action to reduce or eliminate the risk.”
Read more about TINA.org’s continuing coverage of glucosamine here