Glucosamine, chondroitin sulfate are top sellers in US
                                
                                
                                    (Newser) -
                                    Popular nutritional supplements glucosamine and chondroitin sulfate don’t slow the progression of arthritis, a 2-year study finds. Though a combination of the two is the nation's sixth-highest-selling dietary supplement, they didn’t cut cartilage loss any better than sugar pills in osteoarthritis patients, reports USA Today, confirming the findings...