Your first gray hair can come as a shock. Whether it’s silvery sprout or the lightening of the strands around your temples, graying hair happens to women of all ages and there’s no cause for panic.
Professor Ralph Trueb of the Center for Dermatology and Hair Diseases in Switzerland writes about what is now known as the Rule of 50 in his book, The Difficult Hair Loss Patient: Guide to Successful Management of Alopecia. He says that by 50 years of age, 50% of people will have 50% gray hair regardless of gender or hair color.
Why we go gray
Generally, race seems to play a role in premature graying. Hair begins to lose color as early as the age of 20 for caucasians, 25 for Asians, and 30 for Africans. This relates to the observation that the lighter the skin color, the sooner that hair will turn gray. Graying can be genetic so the exact age when it starts is individual.
At the root of this aging process are hair cells called melanocytes that produce a dark pigment called melanin, which comes from the Greek word “melanos,” meaning “dark.” This pigment is what gives color to hair, skin, and the iris of the eyes. Hair color would depend on two groups of melanin. Eumelanin contains brown and black pigments while pheomelanin have red and yellow pigments. Variations in the amount and ratio of each result in a variety of colors and shades.
As we age, our melanocytes produce less melanin, causing our hair fibers to lose their original color. Aging hair, as professor Trueb calls it, is not just a matter of deteriorating hair color but of decreasing production and declining appearance as well.
Relative scalp coverage, which measures the average number of hair fibers in a cross-section multiplied by the number of fibers per square centimeter, usually peaks at age 35. Hair density peaks in the late 20s, but hair diameter can increase until age 45, after which hair growth slows down and fibers grow thinner and coarser. This is why gray hair is more resistant to artificial color.
Aging hair is also more sensitive to ultraviolet rays, which cause hair proteins such as keratin to break down and make hair more prone to breakage. The production of sebum, the oily substance secreted by the sebaceous glands through ducts that open to the hair follicles, also decreases after age 50. The increase of sebum starting from puberty until it peaks from ages 45-50 is what keeps the hair moisturized, shiny, and soft. Declining amounts in older ages translates to hair that lacks luster and is coarse and dry.
Causes of premature gray hair
Some start to grow gray strands in their 20s and some in their 50s. While genetics seems to be the major determinant of when and how our hair goes gray, other factors also come into play.
Drugs. Certain drugs, such as those that prevent malaria, can lead to bleaching or loss of hair.
UV radiation. Constant exposure to ultraviolet rays, such as those from the sun, can damage melanin and gradually bleach hair.
Smoking. Studies have linked smoking to oxidative stress that damages the melanocytes.
Internal damage. For people who bleach their hair with hydrogen peroxide, it is interesting to note that the chemical already naturally occurs within our hair but is broken down by an enzyme called catalase from the fruits and vegetables we eat. When catalase levels decrease, hydrogen peroxide builds up and the hair turns gray.
Nutritional deficiencies. Hair follicles and their pigments are dependent on nourishment provided by a healthy diet. Insufficient calcium, iron, and iodine in your diet can lead to poor hair structure and premature graying.
The bad news is that aging will inevitably bring about thinning, drying, breaking, and fading of hair. The good news is that whatever color we start with, everyone will eventually lose their hair color anyway. It might be all white — but it’s all right.