ACP5 and osteoporosis: Interestingly, another study in 2006 found that in older women the plasma level of antioxidants that are associated with osteoporosis significantly decreased [19], while a 2017 study on the role of antioxidants and OS demonstrated that the addition of H2O2 to cultures of human marrow mononuclear cells led to a higher number and activity of osteoclasts, as well as in the level of tartrate-resistant acid phosphatase [16].