The science of hair

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How linked do you feel to our more hirsute animal relatives?

Along with four-chambered hearts, warm blood and producing milk to nourish our offspring, we humans are linked to all of our mammalian cousins by the presence of a covering of body hair. But humans appear to feel the need to separate themselves more and more from our “animal” roots by removing any hair that springs up that is not on our heads. Where beards and male body hair were once seen as a sign of strength and virility, a mass industry has evolved to literally ‘nip these in the bud’ and the term “The Naked Ape” is becoming more and more relevant.

The fact that body hairlessness is linked to the sexual sign for femininity seems to be fading; rather showing large expanses of hairless flesh is a display now linked to healthiness, perhaps from a time where less hair meant less parasites. Stone-age flint and shell razors have been found, alongside cave paintings of men removing hair from their faces, so this has been a long-time relationship for our race. Many primates also have hairless faces; they help us to see expressions and read people more clearly; beards are often used for disguises and even associated with eccentricity.

Interestingly enough we still prize the presence of hair on our heads. There are many theories as to why man has less hair on his body and retains it on his head – one fascinating, but unfortunately as yet lacking in hard evidence, is the Aquatic Ape Theory. This links our evolution to living by shores and spending much time in the water. It helps to explain our easy ability to swim compared with other primates, the evolution of our brains to depend upon high levels of omega 3 oils from fish, our fatty buttocks that help with buoyancy, how our skeletons were supported to become upright and of course, our relative hairlessness. Little body hair means more streamlining in the water and a hairy swimming cap would protect the head from the glare of the sun on the water.

The main difference between body and face hair and head hair is the difference in length and growth cycles. Body hair alternates between growth spurts – when it can grow about 3mm a day with a bulbous follicle – and periods of lying dormant after about three to six months, when the follicle shrinks and the hair turns rigid. That on the head grows continuous to a long length (set a very individual amount), which has caused anthropologists to believe that it must have evolved to be purely decorative and alluring to the opposite sex. Whilst it still protects our heads from radiation from the sun, it is definitely extraneous to have a full head of luscious curly locks to do this.

Our fight to keep this evolutionary quirk under control has a worthy opponent, as hair is the fastest growing tissue in the body, only second to bone marrow with 35 metres of hair fibre produced every day on the average adult scalp. It is normal to lose 100 hairs per day from the scalp and this continual production requires an enormous amount of building materials, nutrients and energy. What you eat affects the growth and quality of your hair, as it does with the rest of your body. It is essential to obtain adequate amounts of protein and minerals, as they are its main constituents. Vitamins are also important, especially B vitamins, with the quality in growth, colour and shine serving as a good indication of your internal health.

Hair is primarily made from the same substance as mammal fur, reptile scales, bird feathers, claws, nails, horn and teeth enamel. This protein called keratin has molecules which are shaped like helices and fibrous, twisting around each other to form strands called filaments. Hair also contains about 10% water, which keeps it flexible and malleable – dehydration then very obviously leads to dry, brittle hair.

The filaments are encapsulated in a harder outer sheath called the cuticle, which provides mechanical strength to each hair shaft and is made of scaly layers. This allows hair to be formed into different shapes when wet, which will set upon drying and be lost when the hair is wet again. Sulphur is an important feature in hair production as it binds the keratin filaments in the inner cortex together, in sulphur-containing amino acids, which are the building blocks that make up proteins. The main sulphur amino acid is called cysteine, which is found in high amounts in eggs – this forms disulphide bridges between the filaments to make a fairly rigid structure; these are what need to be broken for permanent change of a hair shape as happens in chemical treatments.

It follows logically then that good sources of sulphur foods in the diet can help with the quality and strength of your hair. Increasing your consumption of sulphur containing foods such as eggs, garlic, onions, leeks, fennel, watercress, beans, pulses, peas and the brassicas vegetables such as broccoli and cabbage are the best solution and these also contain good levels of B vitamins. These take part in the metabolism of protein i.e. how you assimilate the protein from food and build it up again into hair, nails and other body tissues. In the unnatural arena of the modern world, it is advisable to take a good quality Multivitamin and Mineral complex with up to 50 mg of each B vitamin.

Sulphur may stimulate the growth of hair, but it is also an antioxidant, which helps protect against age-related free radical damage from pollution, poor diet, stress and chemicals. Avoiding excessive alcohol, fried foods, red meat, and processed fats also reduces free radical production and also serves to potentiate digestion to ensure a greater delivery of nutrients to the hair. The link between digestion and hair health may not be readily obvious, but you are a factory and this is where the fuel and building materials enter the system. You can optimise this process by reducing stress, eating slowly, chewing well, not overeating, and considering taking digestive enzymes. This particularly helps to digest protein, which is a dense substance and requires good levels of hydrochloric acid in the stomach to begin the process of full digestion. Healthy protein sources include fish, lean cuts of meat, eggs, milk, nuts, seeds, oats, grains and pulses and taking a good quality Aloe Vera juice or strong peppermint tea before main meals can help stomach acid production.

Good circulation is also vital to hair growth and health, as the process of hair production requires a constant and strong supply of energy and nutrients. Stress causes these to be diverted away to the heart and muscles as the body assumes it needs to prioritise these for movement in the fight-or-flight response. Digestion is also not considered a priority in these situations, so hair health is doubly affected. Keep stress at a manageable level considering some form of relaxation, such as meditation, massage your hair regularly to promote circulation to the head and hair and exercise regularly.

A healthy diet and regular exercise promotes good overall health, circulation, and hormone balance both in men and women. This is how our ancestors evolved, to exploit the sexual signals that a full head of healthy hair can give out. Hair, like skin is an external sign of health, strength and the ability to protect and procreate. If you strive for these qualities for your body, then your hair will follow suit.