**Popular supplements don’t work**
Many people with osteoarthritis have knee pain. They often try over-the-counter treatments to help the pain, and to avoid knee surgery.
The supplements, glucosamine and chondroitin sulfate, are very popular. In 2012, Americans spent $813 million on these supplements, according to the Nutrition Business Journal.
Knee osteoarthritis begins with breakdown of articular joint cartilage. This is the tough flexible tissue that covers the ends of the knee and other joints. Glucosamine and chondroitin are building blocks of cartilage. But they are not good for pain relief. Here’s why:
1. These popular supplements don’t work:
Many studies have shown that glucosamine and chondroitin sulfate do not help to relieve arthritic knees , , . People who take the supplements often report less pain or swelling of their joints. But people get similar results if they take a placebo—a “sugar pill” with no active ingredients.
2. The supplements can be dangerous:
Glucosamine and chondroitin are not harmful by themselves, but they can interact with other medicines. For example, the supplements can increase the effect of warfarin (Coumadin and generics) on blood clotting . This increases the risk of bruising and serious bleeding. Problems with warfarin cause a third of all emergency room visits among seniors in the U.S .
3. These supplements are a waste of money.
You will spend about $200 a year if you take a glucosamine/chondroitin supplement every day.
To make matters worse, often the labels on the bottles are misleading. In 2013, Consumer Reports tested 16 joint pain supplements and found that seven had less chondroitin than the label listed.
4. Other approaches often work better.
There are more effective ways to relieve arthritic knee pain:
a) Lose Excess Weight. Losing 2.5kg of excess weight can take about 10kg of pressure off your knees when walking.
b) Physical Activity. To build support of the knees, practices exercises that increase quadriceps strength. According to recent MRI studies , greater quadriceps strength prevents lateral offset and tilt of the patella, which protects against cartilage loss at the lateral compartment of the patellofemoral joint, a frequent site of symptom generation in knee OA.
These studies demonstrated that subjects with greater quadriceps strength were also more likely to have less knee pain and better physical function. Overall, the suggested that strong quadriceps muscles have an overall beneficial effect on knee OA.
c) Yoga and other mind-body exercise: A systematic review on supervised yoga and tai chi found that specific mind-body practices may help alleviate pain and enhance physical function in adults suffering from osteoarthritis of the knee.  Additionally, patients practicing Iyengar yoga demonstrated reduced pain and disability caused by knee OA .
 Kwoh C, et al "The joints on glucosamine study: the effect of oral glucosamine on joint structure, a randomized trial" Arthritis Rheum 2014; DOI: 10.1002/art.38314.
 Sawitzke, A. D., Shi, H., Finco, M. F., Dunlop, D. D., Bingham, C. O., Harris, C. L., Singer, N. G., Bradley, J. D., Silver, D., Jackson, C. G., Lane, N. E., Oddis, C. V., Wolfe, F., Lisse, J., Furst, D. E., Reda, D. J., Moskowitz, R. W., Williams, H. J. and Clegg, D. O. (2008), The effect of glucosamine and/or chondroitin sulfate on the progression of knee osteoarthritis: A report from the glucosamine/chondroitin arthritis intervention trial. Arthritis & Rheumatism, 58: 3183–3191. doi: 10.1002/art.23973
 Clegg, D. O., Reda, D. J., Harris, C. L., Klein, M. A., O'Dell, J. R., Hooper, M. M., ... & Williams, H. J. (2006). Glucosamine, chondroitin sulfate, and the two in combination for painful knee osteoarthritis. New England Journal of Medicine,354(8), 795-808.
 Daniel Budnitz, M.D., medical officer, U.S. Centers for Disease Control and Prevention, Atlanta; Knight Steel, M.D., chief of geriatrics, Hackensack University Medical Center, New Jersey; Dec. 4, 2007, Annals of Internal Medicine
 Shreyasee Amin, Kristin Baker, Jingbo Niu, Margaret Clancy, Joyce Goggins, et al. Quadriceps strength and the risk of cartilage loss and symptom progression in knee osteoarthritis. Arthritis and Rheumatism. Available at: http://goo.gl/o8jEe. Published 30 December 2008
 Mind-Body Therapies and Osteoarthritis of the Knee.
Selfe TK, Innes KE.Curr Rheumatol Rev. 2009 Nov 1; 5(4):204-211.
 Kolasinski, S. L., Garfinkel, M., Tsai, A. G., Matz, W., Dyke, A. V., & Schumacher Jr, H. R. (2005). Iyengar yoga for treating symptoms of osteoarthritis of the knees: a pilot study. Journal of Alternative & Complementary Medicine, 11(4), 689-693.