Short-Term Study Finds Little Knee Cartilage Benefit for Glucosamine

11 March 2014 --- A short-term study has found that oral glucosamine supplementation is not associated with a lessening of knee cartilage deterioration among individuals with chronic knee pain. Findings published in Arthritis & Rheumatology, a journal of the American College of Rheumatology (ACR) journal, indicate that glucosamine does not decrease pain or improve knee bone marrow lesions - more commonly known as bone bruises and thought to be a source of pain in those with osteoarthritis (OA).

Speaking to FoodIngredientsFirst, Dr C Kent Kwoh, from the University of Arizona in Tucson, who helped conduct the study, said: “Many studies of glucosamine for knee osteoarthritis have been performed and they have had conflicting results. This is the first study to examine the effects of glucosamine on joint damage in osteoarthritis from multiple different perspectives (ie, MRI to directly evaluate changes in cartilage and bone as well as excretion of products of bone damage in urine and patient-reported outcomes such as pain and function). None of these biomarkers showed any benefit of glucosamine over placebo. In this sense, it can considered as a "breakthrough" study.”

According to the ACR 27 million Americans over 25 years of age are diagnosed with OA—the most common form or arthritis and primary cause of disability in the elderly. Patients may seek alternative therapies to treat joint pain and arthritis, with prior research showing glucosamine as the second most commonly-used natural product. In fact, a 2007 Gallup poll reports that 10% of individuals in the US over the age of 18 use glucosamine, with more than $2 billion in global sales of the supplement.

“Our study found no evidence that drinking a glucosamine supplement reduced knee cartilage damage, relieved pain, or improved function in individuals with chronic knee pain,” explained Dr Kwoh. “Better treatments of knee osteoarthritis are needed and many drugs are in development. From this and other studies, it does not appear that glucosamine hydrochloride is an effective treatment option. Unfortunately, current treatments of osteoarthritis only treat symptoms and are associated with multiple side effects.”

For this double-blind, placebo-controlled trial, Dr Kwoh and colleagues, enrolled 201 participants with mild to moderate pain in one or both knees. Participants were randomized and treated daily with 1500 mg of a glucosamine hydrochloride in a 16-ounce bottle of diet lemonade or placebo for 24 weeks. Magnetic resonance imaging (MRI) was used to assess cartilage damage.

Trial results show no decrease in cartilage damage in participants in the glucosamine group compared to the placebo group. Researchers report no change in bone marrow lesions in 70% of knees, 18% of knees worsened and 10% improved. The control group had greater improvement in bone marrow lesions compared to treated participants, with neither group displaying a worsening of bone marrow lesions. Glucosamine was not found to decrease urinary excretion of C-telopeptides of type II collagen (CTX-II)—a predictor of cartilage destruction.

This study was funded by the Beverage Institute for Health & Wellness, The Coca-Cola Company and the National Institute of Arthritis, Musculoskeletal and Skin Diseases.

By Sonya Hook