Hair 101: The Science of Healthy Hair (2)

Hair growth begins in the skin in a hair follicle and has three phases:

1. Anagen Phase: The Growth Phase

The anagen phase is the longest phase in the cycle, lasting 2-6 years. In this phase, epidermal cells that form the root of the hair continually divide. As they divide, new cells push old cells out, producing the hair shaft. Cell division is facilitated by oxygen, energy and nutrients that are supplied through the bloodstream. For more information, see the post on what hair requires to grow.

About 90% of the hairs on a human head are in the anagen phase at any point in time. Each person has about 100 000 hairs on their head.

2. The Catagen Phase: The Destruction Phase

In this phase, the epidermal cells stop dividing and the production of the proteins found in the hair ceases.

3. The Telogen Phase: The Resting Phase

In this phase, the hair simply remains in the hair follicle but stops growing. The hair can easily be pulled out by washing and combing.

4. The Exogen Phase: The Shedding Phase

In one day, about 50-150 hairs are lost due to the exogen phase. Once the hair is shed, the anagen phase begins, and the cycle continues.

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Hair averages a growth rate of about 0.035cm a day, which is about 1cm a month. This means if a hair grows undisturbed through the anagen phase, it can be as long as 24-72cm.

Product Review: Rainforest Moisture Series by The Body Shop

The great advantage about this series of products is that they do not contain silicones, parabens or sulfates. Sulfate is found in most shampoos and conditioners and is what causes shampoo foam. It’s a very harsh substance that can dry out your hair. Parabens and silicones coat your hair - they artificially make hair feel smooth. However, they block further moisture from entering the hair shaft and cause dryness over time.

I was pleasantly surprised by the moisturising effect of these products. The shampoo (which contains natural oils and honey) cleanses without stripping the hair. The conditioner and hair butter leave the hair feeling luxuriously smooth without weighing it down.

The down side for me was the fragrance. Personally, I like fruity or flowery scents. Unfortunately, these smell, as the name suggests, just like a rain forest.

The Big Chop

Some women choose to cut off all their hair when they start their journey to healthy hair. It is not always practical, and is in fact very scary for some women. So how do you make this all-important decision?

It’s important to closely assess the state of your hair. How badly is it damaged? Do you find lots of small hairs break off after as you comb or brush your hair, or even just from touching it? Is you hair thin, dry and brittle? Are the ends of your hair much thinner than the shaft or the roots? Is your hair over-processed? Do you tend to relax your hair all the way to the tips every time?

If you find that only the ends of your hair are damaged while the roots are fairly healthy, then you can get away with changing your hair regime and having regular trims to remove the damaged ends slowly over time.

If you find that all your hair is badly damaged, from the roots, down the shaft, to the tips, then it would be best to do the big chop. However, if it’s too big a step, you could concentrate on having healthy new hair growth and slowly trimming off your damaged hair. You will therefore not notice any growth in terms of length for some time, but you will certainly have thicker hair growing in, that doesn’t break as much.

Whatever you decide, you must trim your ends at least twice a year. I recommend a trim every 8 weeks when removing damaged hair, then twice a year when the healthy state of the hair has been restored.

Hair 101: The Science of Healthy Hair (1)

In order to achieve healthy hair you must first seek to understand what your hair is made of, what it needs and how it reacts under differing circumstances.

In this instalment, you’ll learn about the structure of hair.

Hair consists of three layers.

The innermost layer is called the medulla. The medulla is filled with air. It may or may not be present in the hair, and is largely found in thick hair.

The layer surrounding the medulla is the cortex. This layer gives the hair its strength and colour. It contains fibres of a special protein called keratin, water, lipids and traces of minerals. It also contains pigment molecules known as melanin that determine the colour of the hair.

The outer layer is a protective layer called the cuticle. The cuticle is several layers of overlapping, translucent sheets organised much like tiles on a roof. The cuticle can open and close.

Now that you know what hair is made of you know what it needs: protein for strength and moisture for elasticity. You can give your hair the protein and moisture it requires from the inside via your diet, or from the outside via hair products. Finding the right balance between protein and moisture is crucial. Too much protein and not enough moisture will lead to dry, brittle hair that breaks. Too much moisture and not enough protein will lead to mushy hair that stretches and snaps when manipulated. If your hair is breaking, it appears not to be growing.

Part two of the science of healthy hair will explore the hair growth cycle. Learning about the cycle will help you figure out why your hair seems not to grow. That’s the first step to growing healthy hair!