Yes indeed, the very same bleach used by Jean Harlow and Marilyn Monroe to turn their mousy brown locks to platinum tresses has been found in scalp skin cells, according to a team of German researchers.

The discovery could one day lead to a "cure" for greying which would allow people to retain their natural hair color all their lives.

It seems the older you get, the more hydrogen peroxide is produced by your body. "The originator of the entire process is hydrogen peroxide, which we also know as a bleaching agent," explains Dr. Heinz Decker, from the Institute of Biophysics at Mainz University in Germany.

"With advancing age, hydrogen peroxide builds up in larger amounts in the hair follicle and ultimately inhibits the synthesis of the color pigment melanin," he says.

It is all very natural and scientists have long known that hydrogen peroxide is a by-product of metabolism, the process by which cells burn fuel for energy.

However, as a person grows older, levels of the enzyme fall and increasing amounts of hydrogen peroxide build up.

Dr. Decker discovered that hydrogen peroxide interferes with the production of melanin by disrupting a key biological pathway.

At the same time, it inhibits enzymes needed for the repair of damaged proteins. This sets off a cascade of events leading to the gradual loss of pigment from the hair's root to its tip.

The research points towards new treatments for both premature greying and the skin pigment disorder.