8 hair care myths untangled

Professor Desmond J Tobin pictured with Dr Zoe Williams for the Horizon special

1. Is your hair alive?

The hair fibres that are visible on your head are fully dead, but the factory that makes them – the follicle – is very much alive.

2. Does shampoo make it shine?

A shampoo or conditioner may make your hair appear thicker and shinier by changing the way individual hair strands relate to one another. If they are lying parallel, the hair will seem flatter. If they are separate from each other you’ll appear to have more volume and give the impression of thicker hair.

Backcombing is a classic case – it makes your hair look enormous, but you haven’t increased the amount of hair you have, or the thickness of each strand, you’ve just changed how the strands interact with each other.

Whether an individual strand can get thicker, as many companies claim, is much more complex: most “thickening” is done by laying product on the surface of the fibre to give it more bulk. Products may claim they can make that happen within the fibre rather than just on the surface, but that’s not true. And do you really think that split ends can miraculously repair? No, you clip that bit off and you start again.

3. When to wash it?

In my opinion, there’s just no need to wash your hair every day. How often you wash it depends on your type of hair. If you have dry or afro hair you may only need to do it every week or every two weeks. But if you have thinner or oilier hair, or are in an environment where there’s a lot of pollution, or where you’re likely to get dirtier, you’ll want to wash it more.

4. Can hair clean itself ?

There is a theory that if you don’t wash your hair for a period of time then it will clean itself. That’s true – sort of. Natural oils called sebum, when brushed through your hair, remove particles of dirt and grime. But that alone would never have the same look as hair that has been shampooed and conditioned. How well the theory works would depend on the length of the hair. People with short hair may have an easier time trying it, but those with long hair might find that a natural “sebum-clean” effect may not give them the look they want.

5. Does everyone go grey?

There are exceptional cases, but the vast majority of us will eventually go grey. There is ethnic variation
– Caucasians tend to grey quicker than other ethnicities, but how quickly you appear to go grey depends if you have blonde, black, brown or red hair. If you have black hair, a lot more of your strands can turn white before it looks like you have grey hair. But if you have blonde hair you tend to appear grey extremely rapidly. There is also some suggestion that people who smoke will go grey earlier, and there’s some evidence that stress affects hair growth and pigment. The claim that if you pluck one grey hair, more will sprout, is a total myth.

6. Can you stop baldness?

You can’t stop balding, but you can slow its progress – and two products have been proven to work. The world’s number one regulatory body for drugs, the FDA in the US, has approved an over-the-counter treatment called Minoxidil, which is applied to the scalp, and Finasteride, which is a prescription drug that you ingest. They can prevent further loss, or help regain some previous loss, but there’s no sense in using them if you’re already bald. And if you stop using them you’ll lose the ground that you made up.

7. Is baldness down to Dad?

You have to look at both parents to get a valid assessment of the likelihood for baldness. An androgen receptor gene associated with male pattern alopecia is only found on the X chromosome, which is actually inherited from your mother. But that alone is not sufficient – lots of other genes work hand in hand and many of those are inherited down the male side.

8. Are blow-drys bad?

If you use a hairdrier or hair straighteners from a reputable manufacturer they won’t cause excessive damage to the hair. But obviously the temperature and duration of contact will determine when you go from styling to frying. Most of the time, if you’re not mistreating your hair elsewhere, and are following a hair-care regime that’s putting back anything taken out by one particular procedure, you’re probably OK. It’s all about balance.

Horizon: Hair Care Secrets is on tonight at 9pm on BBC2