Knees Achy? Drink A Glass Of MilkArthritis of the knees tends to start developing as early as the mid-20s. For some, it's not that big a deal. For others, it rapidly advances until there is a lot of pain as bone rubs on bone from a loss of cartilage. CBS4 Medical Editor Dr. Dave Hnida looks at a new study which says low fat milk may protect your knees by slowing down everyday wear and tear.