Special Interest Topics
“Aged? But he does not appear aged, just look, his hair has remained young!”
- Marcel Proust, Remembrance of Things Past
It does seem as though President Obama is graying more quickly than in years past. The normal incidence of graying hair is 34 years of age in whites and 43 in blacks. While there are several skin conditions associated with hair whitening (i.e. vitiligo), the large majority of us go grey based on genetic determinants. It is a total myth that this “grey” trend passes through the female line - rather, the phenomenon is thought to be dispersedly inheritable through both sides of the family line. Recent data suggests that hair graying is the result of premature death of pigmented stem cells (called “melanocytes”) that reside within hair follicles. As our hair grows, its color is maintained by melanocytes that reside at the base of the hair shaft or “bulb”. Should this bulb be damaged, hair will assume its unpigmented state and appear grey! The cause of this early cell death within the bulb is hotly debated, but leading researchers in the field have narrowed things down to 2 contributors:
1) Free Radical Damage - Investigators have found that most greying hair shares a common feature. A DNA deletion in the gene that protects against oxidative stress, that is, a defective gene that normally protects cells from the damage that occurs from ultraviolet light, environmental toxins, and psychological stress. These insults all generate free radicals, charged particles that grossly impede the function of normal cells and likely destroy the fragile stem cells that produce hair pigment. (1)
2) Decreasing tyrosinase. Tyrosinase, an enzyme that converts hair pigment (melanin) to its active form for incorporation within the hair shaft, gradually decreases over time. Patients with grey hair can still make pigment, but because of low tyrosinase levels, this pigment is never successfully transferred to the hair shaft. While advanced age can certainly account for low tyrosinase levels, emotional stress or sudden psychic truama (“I’ve seen a ghost!”) can result in markedly depressed tyrosinase levels. Interestingly, while gray hair is usually coarser and relatively resistant to coloring, it tends to grow at a much faster rate. (2)
So what might the President use in search of darker locks? There is older data to support the use of massive doses of p-aminobenzoic acid (PABA) (3), but gastrointestinal side effects in these studies were frequent and prevent its routine use. New therapies mostly focus on tinting techniques with permanent dyes and henna derivatives, although some experts now counsel patients to include an anti-oxidant shampoo (containing feverfew and licorice root) in their hair care regimen. (4)
Are President Obama’s stress levels definitely contributing to his increased greying via the production of free radicals and decreased tyrosinase levels? Well, they certainly aren’t helping any.
1. FASEB J. 2006 Jul;20(9):1567-9. Epub 2006 May 24.v
2. Clin Interv Aging. 2006 June; 1(2): 121–129.
3. Science. 1941;94:257–8.
4. J Cosmet Sci. 2001;52:103–18