Grey hair remedies: No genie in the bottle

West Yorkshire, England - Marketers hawk melatonin, copper blockers, special shampoos and vitamins as remedies for grey hair.

But according to Desmond Tobin, Ph.D., a professor of cell biology at the University of Bradford in West Yorkshire, England, there is no effective treatment except dyes. And some scientists are concerned about their toxicity.

Forget melatonin, he adds.

What about L'Oreal's claim to have identified the genes that turn hair grey? Or the company's development of a precursor molecule for melanin, dihydroxyl-5.6-indole, which advertising describes as "a new way to enhance hair color or hide the gray."

Dr. Tobin has collaborated on studies initiated by the cosmetic industry and thinks L'Oreal, Procter & Gamble, Unilever and others are performing good research. Nonetheless, he's skeptical of such claims.

To begin with, the doctor says, "I doubt there are just a few genes responsible for grey hair. There could be dozens involved, leading to an entire cocktail of biochemical events."

On top of that, the scope of interventions available to the cosmetics industry is broadly limited to topical solutions; otherwise, therapies risk classification as drugs. And when it comes to shampoos and potions, Dr. Tobin says, "I'm a skeptic because it's very difficult to get active agents deep into the skin."

Neuroendocrinology, emerging discipline

Dr. Tobin's interest in grey hair dates back more than a decade when he was studying alopecia areata, an unusual disorder that causes pigmented hair to quickly fall out, resulting in a blanched head of hair. (If reports of Marie Antoinette's sudden aging in the days prior to her appointment with the guillotine are correct, she may have had this autoimmune disorder.)

Later, his research focused on the biology of hair and skin melanocytes. Skin cells never stop making pigment and increase their production in the presence of UV radiation. Hair cells, on the other hand, wear out and diminish in number. Since hair sheds and it grows in a cyclical pattern, Dr. Tobin decided the follicle was an ideal model system for study. He was the first to grow melanocytes from hair follicles in culture and is now growing both hair and skin melanocytes from the same person in order to compare and contrast without exogenous factors confusing results.

The doctor says, "The data we've published so far suggests that most of the same neuropeptide proteins associated with the brain and nervous system are also in operation in the hair follicle. Some of these can stimulate melanocytes to produce more melanin and to become more dendritic, donating melanin to surrounding cells."

He points out that people are beginning to think about the skin not just as a barrier but also as a sensor. Consequently, an important new discipline - neuroendocrinology of the skin - is emerging.

A small subset of this large, uncharted medical domain is the study of grey hair. Progress is happening but not nearly so fast or in such dramatic ways as implied by some in the cosmetic industry, Dr. Tobin says.

For example, white follicles taken from someone who has been grey-haired for a long time still have melanocytes. They are greatly reduced in number and dormant but manage to survive for decades. By exposing these melanocytes to peptides and/or chemicals, Dr. Tobin has persuaded them to repopulate and produce melanin - in vitro.

Next, he hopes to determine which environmental factors are particularly problematic for aging hair melanocytes. He thinks it could be a nutritional deficiency, a stem cell deficiency, the inability of melanocytes to migrate, an enzymatic factor or an inability to avoid oxidative damage.

In a decade or so, these various lines of inquiry could lead to a genie in a pill.