Have you ever spent much time thinking about your hair? Not just the colour or style, but what your hair is actually made up of? It’s actually pretty interesting when you stop to think about it – every human head of hair is a little bit different, and not all animals have hair! In fact, hair is one of the key defining traits of mammals, cementing our status in the animal kingdom. Hair is actually a protein filament, but the way it presents on humans has a lot to do with a long history of evolution and a number of genetic traits and external environmental factors. Over the course of history hair has been a key signifier for issues of race, gender, class, religion and sexuality. The texture and style of one’s hair can say a lot about their culture, personality or social standing and ‘hair’ has come to be much more than just a number of follicles emerging from the dermis. Hair has changed a lot of the course of history; changing hairstyles have been a clear symbol of changing attitudes amongst other things – so hair is actually a lot more interesting than you might expect. There are a lot of interesting facts about hair out there that you probably don’t know about, so if you’re curious to know some curious tidbits about your luscious locks then read on below.
Hair volume facts
Did you know that the average human usually has approximately 100,000 to 150,000 individual strands of hair on their scalp. Light haired people, like blondes, usually have more hair follicles than darker haired or red headed people. Blonds average 120,000 hair follicles, whilst dark haired people have around 100,000 and red heads average only 80,000. You are born with all of your hair follicles, more hair follicles will no grow over time and there is no way to increase the number of follicles you have – if you have thin hair or not a lot of it, there’s not much you can do about it!
Hair growth facts
Did you know that the protein filaments that make up your hair are actually the fastest growing tissue on your body? The only thing that grows more quickly than your hair is your bone marrow. On most human head, about 25 metres of hair fiber is produced each day. At the same time as your hair is growing, it also sheds. Hair growth happens in cycles, known as the growth or ‘anagen’ phase, resting or ‘catagen’ phase and shedding or ‘teolgen’ phase. On average, 90% of your scalp might be in growth phase whilst 10% might be in rest phase. Everybody sheds hair each day; the average is 40 to 150 strands per day whilst your hair will grow around 0.3 to 0.5 mm each day. The growth stage of each hair follicle lasts on average 3-5 yeats, although this shortens as you age. The number of hair follicles that you have drops as you age. On average each follicle on your head will grow an entirely new hair up to 20 times. You can expect it to take about seven years to grow your hair down to your waist, and almost three years to grow it to your shoulders – the average lifespan of a hair follicle before it sheds is between 4 to 7 years. It might surprise you to know but your hair will actually grow faster during different seasons and ages, the growth rate is fastest in summer, during sleep and in your teens to early twenties. There’s not really much you can do to influence the speed of hair growth, some people believe that cutting their hair will make it grow more quickly but this is untrue – although it is the only way to remove split ends. The way your hair grows is due to ‘hair streams’ which cause the natural part that you might have noticed. Gender and race tend to have an influence on how quickly hair grows, most men find that their hair grows more quickly than woman, whilst African hair grows most slowly and Asian hair grows most quickly on average. If you’re wondering why you don’t end up with extremely long hair all over your body, it’s because the growth cycle of your body hair is shorter than the hair on your head.
What hair is made of
Your hair is made up mostly of a protein called keratin, which is the same protein that is found in your skin and fingernails. Keratin also makes up the claws, feathers, horns, hooves, beaks and quills of other animals. The average strand of human hair is around .02 to .04 mm thick. Keratin is made up of an amino acid known as cysteine, this gives hair its structure. The structure of the hair consists of an outer layer called the cuticle which protects the inner layers. Damaged hair has more open cuticles. The middle layer of the hair is made up of proteins twisted together and is called the cortex. Inside this layer is called the medulla. Very fine hair does not contain the innermost layer. The actual make up of your hair contains mostly carbon, oxygen, nitrogen, hydrogen and sulphur. Small amounts of magnesium, arsenic, iron, chromium and other metals and minerals can also be found on the hair. Darker shades of hair contain more carbon than light hair. Scientists can tell a lot about what people have consumed based on their hair, although they can’t tell gender based on your hair. The colour of your hair is determined by melanin, which also impacts on the colour of your skin and eyes – only a tiny percentage of the world’s population has naturally red hair. The hair you can see on your head is actually dead, and is shown to become increasingly dry as we age.
Hair loss facts
Some things that humans do can impact on their hair growth and shedding cycle to increase hair loss or even cause permanent hair loss. Often changes to the diet or what we put in the body can impact on your locks and potentially cause hair loss. Extreme dieting or crash dieting for example can cause hair loss, this is usually temporary and corrects when a healthy, balanced diet is resumed. Hair growth relies on the proper nutrients and vitamins being present in the body, starvation or dieting can cause your body to shed hair as it diverts protein away from your hair follicles. Certain medications or drugs can cause hair loss, as can deficiencies such as iron deficiency. Certain conditions like thyroid imbalances can also cause hair loss. Genetic factors can also cause hair loss. A lot of people will experience thinning and balding in their lifetime as they age – up to 40% of women will experience female pattern hair loss over the course of their life, usually following menopause, whilst 50% of men will have male pattern baldness by the age of 50. Balding is usually not apparent until over 50% of hair has been lost. Most women will discover that they lose some hair after giving birth, because hormones can impact on the growth and shedding cycle. There are medical conditions like alopecia that can cause hair loss. The only permanent solution for hair loss and balding is hair transplantation, which can be invasive and expensive.
Hair and ageing facts
Wondering why you’re going grey? Hair actually turns grey because the pigment cells in the hair stop working correctly over time, aging and stress slows down melanin production which causes your grey hairs. The scientific word for grey hair is actually canities. It can take almost two weeks before you will see grey hair, as hair is produced under the skin.
Hair product facts
Shampoo, conditioner and heat styling tools are now an everyday part of life but it wasn’t always this way. The first ever liquid shampoo was only made available on the market in 11952. Most shampoos we use today are designed to be slightly acidic to help smooth out the cuticle of the hair. The first ever hair dye was developed in 1907, nowadays many store bought hair dye products contain mineral salts and other ingredients that can damage the hair when combined with salon treatments like perms. The first product targeted specifically at men was developed in 1928, it was a hair product made from beeswax. The curling iron predated both hair products and was actually invented all the way back in 1875! When it comes to hair removal, the earlier form of it can be traced back to the Turks who created a paste made from arsenic, quicklime and rose water to get rid of unwanted hair.
Hair strength facts
Did you ever wonder about how Rapunzel supported the weight of a prince with only her hair? Well it turns out it’s stronger than you’d think, your whole head of hair is actually capable of supporting up to 2 tonnes of weight. Your hair strength is equivalent to iron wire and stronger than copper wire of the same diameter, it will only rip after a force of more than 60 kg’s is exerted upon it. Hair is also incredibly elastic, capable of stretching up to 70% before snapping. When it’s wet, your hair will stretch to be up to 30% longer than its usual length.
Hair texture facts
You’ll notice that different people have different textures. Your genetics and where you’re from have a lot to do with it. For instance, Asian hair is most often straight and black or dark brown. Different textures look different under the microscope. The texture and shape of hair can be impacted by heat styling tools and water because they change the hydrogen bonds of the hair.
Hair concern facts
Most people will struggle with some kind of hair concern at some point in their lives, whether it be dandruff, split ends, dry scalp, damage, frizz or greasy hair. Some issues are more serious than other. The disorder called ‘trichotillomania’ can be quite serious for instance, as it involves compulsively pulling out your hair due to stress – this can cause permanent hair loss. Stress can also have an impact on milder conditions like dandruff, which is called by a common fungus called malassezia globosa. Damage like split ends can only be treated with a haircut, although many remedies exist to try and prevent or fix damage. All the way back in the sixteenth century a doctor claimed you could fix damaged hair with a concoction that contained boiled slugs!
Hair and the body facts
Have you ever noticed that the only parts of the human body that aren’t covered in hair are your palms, the soles of your feet and your lips? Almost the entire human body is covered in body hair! The human body actually contains almost 5 million hair follicles. It’s no wonder then that the average man spends up to 5 months of his life shaving – especially because facial hair grows faster than the rest of your body hair.
So there you have it! The more you know. If you didn’t ever stop to wonder about the evolutionary feat that is our hair, then you’ve certainly caught up with our fun facts. Your hair is your bodies way of protecting you from the elements, but it’s become so much more than that over the course of history. Now days it’s a major signifier of who we are and advances in hair products and hairdressing techniques have given us more control over how we cut and style our hair, allowing us to do amazing things with what is essentially a collection of protein filaments!