Leek plants such as onions, garlic and leeks contain an ingredient called diallyl disulphide, which suppresses certain enzymes in the body that reduce the basic substance of cartilage. 

For example, regular consumption of leek vegetables keeps the hip cartilage strong and hip wear and tear and hip arthrosis occur much less frequently. Women from the menopause onwards suffer particularly frequently from the consequences of cartilage wear. Women who regularly eat onions, garlic or leeks over the years have fewer hip problems and stronger bones later on.