Healthy hair gets its shine from a thin coating of sebum - a substance which is secreted by the scalps sebaceous glands near the root of each hair.
If the sebaceous glands become overactive and produce too much sebum, the result is greasy, lank hair. Use the mildest shampoo possible, and wash your hair as often as necessary (lathering only once each time).
Some say that cutting down on sugary foods may help prevent an oily scalp.
