Apparently, until clinical trials can demonstrate its safety, chondroitin does not necessarily appear to cause prostate cancer, but it does appear to help speed prostate cancer progression if you already have it. Some men may have the beginning stages of prostate cancer and don't know it yet, so better to be safe and stay away from chondroitin. It is even possible that future clinical trials will demonstrate that chondroitin does cause prostate cancer.
Also chondroitin made from cow cartilage may cause mad cow decease if contaminated.
..."You can find versican on the surface of a wide range of cancer cell types. In general,
the greater the amount of chondroitin-containing versican bound to the cancer cell, the more likely it is that the cancer cell will be able to spread widely throughout the body. There is sufficient documentation of this effect of versican for prostate cancer, melanoma, some brain tumors, and a range of other cancers. For example, the amount of chondroitin sulfate found associated with prostate cancer in radical prostatectomy specimens correlates with the risk of recurrent disease"...
..."All of this science suggests that
taking the sufficient amount of chondroitin sulfate to protect the cartilage lining of your joints might also foster prostate cancer progression, as well as the growth of other malignancies. I recommend you avoid chondroitin sulfate until clinical trials can demonstrate its safety.
Alternatively, I recommend glucosamine, because there is no evidence that glucosamine fosters the progression of prostate cancer. Furthermore, a randomized controlled clinical trial shows that glucosamine preserves the thickness of joint cartilage, thus slowing the progression of osteoarthritis. In this trial, they used daily glucosamine sulfate doses of 1,500 mg over a three-year period."
http://www.malecare.com/new_page_26.htm"Chondroitin can be manufactured from cow cartilage, so
there may be an extremely remote possibility of contamination with the infectious protein (prion) that causes bovine spongiform encephalopathy (BSE, or
mad cow disease)."
Potential side effects Side effects of glucosamine and chondroitin are usually mild. Some people may experience nausea, diarrhea, constipation or heartburn. Other possible side effects, according to the Natural Standard Research Collaboration, might include:
Glucosamine. Drowsiness, insomnia, headache, skin reactions, sensitivity to sun or nail toughening and, rarely, abdominal pain, loss of appetite, flatulence, temporary increases in blood pressure and heart rate, or palpitations. Studies on animals theoretically suggest the possibility of an increased risk of cataracts.
Chondroitin. Headache, motor uneasiness, euphoria, hives, rash, sensitivity to sun, hair loss, breathing difficulties, tightness in throat or chest, exacerbation of previously well-controlled asthma, chest pain, increased blood pressure, edema (swelling) in the legs or eyelids, gastrointestinal pain/dyspepsia, transaminitis, theoretical increased risk of bleeding or (in animal studies) suppression of bone marrow.
http://www.gulfmd.com/ortho%20-%20bone/Glucosamine%20Chondroitin.asp?id=25