Hair Education

The Structure of Hair

Human hair is made from a protein called keratin, it also contains some moisture and trace minerals and metals found in the rest of the body. The visible part of the hair, called the shaft, is composed of dead tissue: the only living part of the hair is its root, the dermal papilla, which lies snuggle below the surface of the scalp in a tube-like depression known as the follicle. The dermal papilla is made up of cells that are fed by the bloodstream.

Every hair is made up of three layers. The outer layer, called a cuticle is the hairs protective shield and has tiny overlapping scales, like tiles on a roof. When the cuticle scales lie flat and neatly overlapping the hair feels silky soft and glossy. If hair is broken,, dull, brittle and prone to tangling it means that the cuticles are not lying flat and that they have been physically or chemically damaged.

Under the cuticles lies the cortex, which is made up of fibre-like cells that give hair it’s strength and elasticity. The cortex also contains the pigment called melanin, which give the hair its natural colour. At the centre of each hair is the medulla, consisting of very soft keratin cells interspersed with spaces. The actual function of the medulla is not known, but some authorities believe that it carries nutrients and other substances to the cortex and cuticle. This could explain why hair is affected so rapidly by changes in health.

Sebum is the hairs natural conditioner which creates shine. Sebum is an oil composed of waxes and fats and also containing natural antiseptic that helps to fight infection. Sebum is produced by the sebaceous glands present in the dermis. The glands are linked to the hair follicles and release sebum into them. As a lubricant sebum gives an excellent protective coating to the entire hair shaft, smoothing the cuticle scales and helping hair to retain its natural moisture and elasticity. The smoother the surface of the cuticle, the more light will be reflected from the hair, and therefore the glossier appearance of the hair. This is why is is more difficult to obtain a sheen on curly hair than on straight hair.

Under some circumstances, for example excessive hormonal activity, the sebaceous glands produce too much sebum, resulting in greasy hair. On the flip-side, if too little sebum is produces the hair will be dry.

 

The Growth Cycle

Hair that has grown through the scalp is dead tissue, the only part of the hair that is living is underneath the scalp. Hair goes through three stages of growth: the anagen phase when it actively grows; the catagen, or transitional phase when the hair stops growing but cellular activity continues in the papilla; and the telogen, or resting phase, when growth stops completely.

During the telogen phase there is no further growth and the cycle begins again. The anagen phase continues for only about 15-20 days and the telogen phase for 90-120 days. At any given time, about 93 percent of an individual’s hair is in the anagen phase and 1 percent is in the catagen phase and 6 per cent in the telogen phase. Scalp hair which reacts to hormonal stimulation just like the hair on the rest of the body, is genetically programmed to repeat its growth cycle 24-25 times during the average person’s lifetime.

The Importance of Diet

What you eat is reflected in the health of your hair. Like the rest of the body, healthy, shining hair depends on a good diet to ensure it is supplied with all the necessary nutrients for sustained growth and health. Regular exercise is also important as it promotes good blood circulation, which in turn ensures that vital oxygen and nutrients are transported to the hair root via the blood. Poor eating habits and lack of exercise are soon reflected in the state of the hair; even a minor case of ill health will usually make the hair look limp and lack-lustre.

An adequate supply of protein in diet is essential. Good sources include lean meat, poultry, fish, cheese and eggs, as well as nuts, seeds and pulses. Fish, seaweed, almonds, brazil nuts, yogurt and cottage cheese all help give hair strength and natural shine.

Whole grain foods and those with natural oils are highly recommended for the formation of keratin, the major component of hair. Seeds are a rich source of vitamins and minerals as well as protein. Try to eat at least three pieces of fruit a day as it is packed with fibre, vitamins and minerals. Avoid saturated fat, which is found in red meat, fried foods and dairy products. Choose skimmed or semi-skimmed milk rather than the full fat varieties, and low fat cheese and yogurt instead of full fat cheese and cream. These foods all provide nutrients that are essential for luxuriant hair.

If you eat a balanced diet with plenty of fresh ingredients you shouldn’t need to take any supplementary vitamins to promote healthy hair growth.

Hair Facts

A single hair grows approximately 12mm every month.
A single strand lives for up to seven years.
If a person never had their hair cut it would grow to a length of about 107cm before falling out.
Women have more hair than men.
Hair grows faster when you are sleeping.
Hair grows faster in the sun.
Hair grows the fastest when you are aged between 16 and 24.
Between the ages of 40 and 50 women tend to lose about 20 per cent of their hair.
Hair becomes drier with age.