Causes of Grey Hair and Hair Loss
Causes of Premature Grey Hair
When hair grows, it is either pigmented or white. The greyish appearance of hair is only a kind of optical illusion, produced by the mixture of coloured hair with white hair. Premature greying is for the most part genetically determined. Additional causes for grey hair (or white hair) at an early age are excessive stress, constant tension, smoking and certain medical conditions such as thyroid disorder, vitiligo, chronic vitamin B deficiency and anaemia. However, greying is natural. Grey hair is typically a result of aging. Pigment in the hair shaft comes from special cells at the root of the hair called melanocytes. These cells are genetically programmed to make a certain amount of pigment (melanin) at specific ages. At some point in the aging process, these cells make less and less pigment until they cease producing pigment altogether. No matter whether you are a 20 year old, premature grey hair sufferer or 70 years old, the principal reason for your greying hair is the same. The lifespan of pigment-producing cells is determined by your genetics and it is completely individual. But do not despair; premature greying has nothing to do with your life expectancy. The average Caucasian person starts turning grey at the age of 34, whereas the average for Asians and Africans is 47 years. In general, it is considered premature if more than 50% of a person's hair is white by the age of 40.
Causes of Hereditary Hair Loss
Myths: Many people believe that stress, bad circulation, wearing hats and long hair or masturbation cause hair loss. This is not true.
Reality: Dihydrotestosterone (DHT) is a biologically active metabolite of the male hormone testosterone that some suggest is the main cause of both female and male pattern baldness. DHT is formed primarily in the prostate gland, testes, hair follicles, and adrenal glands, where the male hormone testosterone interacts with the enzyme 5-alpha reductase. DHT also plays a role in the development of benign prostatic hyperplasia (BPH) and prostate cancer. DHT causes the hair follicles to shrink and grow finer hair that is lighter in colour, shorter and less deeply rooted than before. Most often, the hair in the balding region will continue to grow at an increasingly slower rate until hair growth ceases completely. The exact mechanism by which DHT acts on hair follicles, causing growth to slow is not known. DHT only works on certain hair follicles that have the genetic predisposition to be shut off. Usually, these are on the front and top of our heads. In most people affected by hair loss, male hormone levels are the same as in normal people but because there are more receptors in the balding areas of the scalp they are affected as if their hormone levels were higher than normal. An interesting fact is that castrated males (eunuchs), who do not produce testosterone (and hence can not make DHT) because they do not have testicles, do not suffer from male pattern baldness.
Contributing factors: Some observations from Asia suggest that diets rich in fat from red meat and sugar might speed up the balding process.