Nutrition.
Eating whole foods & ensure the body is well nourished. Taking a QUALITY fish oil supplement (Yes - I intentionally bold, underlined, italic, capslock). Not all are created equal & the market is unregulated, taking low quality supplements can do more harm then good - do your research. Also a glucosamine sulfate supplement - Helps regulate normal cartilage formation by encouraging production of collagen and by acting as a building block for proteoglycans, which bind the water that lubricates and cushions the joint.
Being proactive with nutrition instead of reactive.
*** This is not intended to be medical advice. Always consult your doctor/health care provider before supplementing. I am speaking from personal research (Kinesiology Major) and personal experience ***