Cartilage acts like a pad or cushion, protecting your bones at the joints during movement. In older adults and younger people who are very physically active, like athletes, cartilage may start to break down and become less cushiony over time. This can lead to friction and pain, especially in well-used joints like the knees -- a condition known as osteoarthritis. Your doctor may recommend pain relievers, supplements or surgery in extreme cases, but your diet can also help you manage your condition and even build new cartilage. Beat Inflammation The University of Maryland Medical Center recommends an anti-inflammatory diet to help prevent and manage osteoarthritis. For this diet, boost consumption of fresh vegetables and fruits, whole grains, legumes, lean protein from poultry and cold-water fish, and healthy fats from olive oil, nuts, seeds and avocado. In particular, UMMC suggests garlic, onions, parsley, watercress, celery and lemon for their anti-inflammatory potential. Your j...