The hair on your body is one of the accessory structures of your skin. Each one of our bodies is made up of millions of hair follicles from which hairs grow. Most of the hair on your body is lightweight, downy and fine. It’s noticeably absent on your palms, soles, nipples and lips. The hair on top of your head is longer and coarser. It’s like that because it helps to keep body heat in. During your teenage years when your hormones are surging, stimulation of hair follicles occurs. As a result hair growth in your armpits and pelvic regions increases. For men, the growth of hair on the face and neck are likewise increased.
A single hair arises from a hair follicle. A hair follicle is a microscopic tubular structure made up of epidermal cells that extend into your dermis (deeper layer of your skin where essential structures are located) for blood supply. The cells located at the bottom of the hair follicle (root) are continuously dividing to produce new cells. These new cells are added to the end of your hair (shaft). The older cells are pushed up through the layers of the epidermis and as they grow keratinisation happens. Keratinisation is the process where keratin filaments (proteins used for building and support) are incorporated into each hair cell.
As you proceed to the more distal parts, the hair cells lose their nuclei and organelles. As time passes, the metabolism of these hair cells will stop and the hair cells will commit suicide, uhm, undergo programmed cell death (die). At this point, keratinisation is complete and your hair cells are completely filled up with keratins. Is hair then alive or dead?
It all depends on which part of the hair you’re referring to. The part of the hair found inside the hair follicle is alive. The shaft of the hair (visible part) doesn’t have any biochemical activity in it and according to dermatologists, is considered dead. The visible parts of your hair contains dead keratinised cells.
Why do we humans have hair on our heads but not on our bodies like other mammals?
Throughout the years, scientists and other experts have tried to come up with reasonable answers. Here are some of them:
We lost the hair on our bodies to free ourselves from external parasites. These parasites are the same ones that infect the fur of animals and include fleas, ticks and lice. Just imagine if you had fur and you contracted fleas. Start scratching Scooby Doo.
Some experts have hypothesised that we lost body hair as an additional sign of sexiness. Bare skin has its appeal to both sexes. Like a peacock’s tail, bare skin may have its significance when it comes to one’s sex appeal.
Why do women have less body hair?
Women have less body hair because their hair follicles are less responsive to hormones compared to men.
Why are there different hair colours?
The hair on your body contains a pigment called melanin. There are two types of melanin: eumelanin and pheomelanin. If you have more eumelanin, your hair color will be darker. In contrast, if there’s less eumelanin present, your hair will be lighter. Eumelanin is further subdivided into black and brown eumelanin. If you have more black eumelanin, your hair will be darker (black and brunette hair). Conversely if you have only a small amount of brown eumelanin, you will have blond hair.
What about the redheads? If you’re a redhead, you have more pheomelanin in your hair. So the colour of your hair depends on the types of pigments that predominate.
Why does hair turn grey?
As we grow old, the production of melanin in our skin and our hair decreases. Grey hairs only have small amounts of melanin in them. White hairs don’t have any melanin at all. You’ll be surprised to know that the whiteness of white hair is just an optical illusion. It’s all because of the way it reflects the surrounding light. The reason why some peoples hair turns grey faster than others is largely determined by your genes and nutrition.
Vital nutrients for your hair
Even though a part of your hair is dead, you still need to feed the part that’s alive. Here are some nutrients you will need to pay attention to so that you have healthy hair:
1. To prevent dull hair colour and a parched scalp, you need vitamin B12, iron, protein and omega-3 fatty acids.
2. For optimum amounts of sebum (natural hair conditioner), you need dark, leafy green vegetables which are rich in vitamins C and A.
3. If your hair is brittle, you may be deficient in biotin. Biotin activates some enzymes involved in the metabolism of carbon dioxide.
4. If you shed too much hair, your intake of zinc may be suboptimal. Together with selenium, both nutrients provide a healthy scalp and prevent hair loss. Calcium is also important for healthy hair.
You will need a healthy diet to keep your hair strong and healthy. Avoid chemical hair products as much as possible, especially hair dyes. You’re literally poisoning your hair and your scalp. Instead find natural, non-synthetic hair care products.