What do you think about taking glucosamine and chondroitin daily not to cure but to prevent arthrosis and arthritis when you are still rather young?

Worthless: There is no data that these supplements will prevent arthritis. Save your money.

While it's not: Likely to hurt you there really is limited data to suggest any real preventative value. There is some evidence for pain relief but it is quite weak. You are better off making sure you eat healthy, remain physical active and keep a healthy weight.