Eggshells and whites are very high in hyaluronic acid (nutritional supplement used to reduce inflammation and to lubricate joints). Save your broken egg shells in the freezer for the next time you are making a soup with a long simmer time, such as chicken soup. Throw them in with the chicken carcass and strain out the shells at the end, for a highly nutritious chicken soup.  You can also rub the egg whites left in the shells all over your face and let air dry before rinsing off, for a fast, easy, inexpensive facial that tightens the skin and cleans the pores.