Why you should use sunscreen for your hair

With excessive sun exposure, hair may become dry, dull, discoloured and fragile, and prone to split ends and frizzing.

Why does this happen?

When ultraviolet (UV) light penetrates the hair’s cuticle (the protective, outermost layer of the hair shaft), highly reactive molecules called “free radicals” can be produced.

These cause damage in a number of ways:

Colour changes
Melanin, the natural pigment that gives your hair colour, offers some protection. It combats free radicals, and also absorbs and filters UV light. However, excessive UVA radiation damages the pigment, causing colour changes. This happens in every kind of hair, although the damage is more apparent in light-coloured hair, which contains less melanin. (Sunlight also dries the hair, which fades any artificial hair-dye present or makes it look “brassy”.)

Structural damage
With exposure to UVB radiation, the free radicals attack hair proteins, especially keratin, from which the hair shaft is primarily composed. This damage is more severe than the effect of UVA radiation.

Of course, sun damage to your hair isn’t as serious as damage to the skin. The living parts of hair (follicle, root, root sheath and sebaceous gland) lie under the skin and are protected. The visible hair shaft itself is non-living, so it can’t get cancer from UV exposure. Even if it’s damaged, it soon gets replaced by new growth.

However, in the short term, damaged hair affects the appearance, which is important for our confidence and self-image. If you’re not happy with the way your hair looks, you might feel insecure and uncomfortable.

Fortunately, it’s possible to protect your crowning glory, just as you routinely protect your skin. You might not be aware of hair sunscreens, which are relatively new to the market, but many products designed to filter UV and repair and protect the hair shaft are now available.

Some shampoos and leave-in conditioners contain sunscreen, and you can also buy oils and hairsprays with SPF (sun protection factor) labelling. (Although be warned: sprays may contain alcohol, which can damage the hair.)

The science of hair photoprotection is still a fairly new field, currently attracting a lot of research in the hair-care industry. On the whole, hair sunscreen products are not yet quite as effective as those designed for the skin. Use them, but also keep in mind these other protection tips:

- You can also apply ordinary skin sunblock to your hair before going into the sun (spray-on products are a useful option). Remember to put sunscreen along a parting, and rub it into the scalp where you have thinning hair. If you’re tying your hair up, don’t forget to put sunscreen on your ears and the back of your neck – areas usually covered by hair.

- Wear a hat. The best hats have wide brims to shade the face, and are made of material that allows the hair and scalp to “breathe”. Braid or pin up longer hair under a bandanna.

- Moisturise your hair to prevent excessive drying. Some hair-care experts recommend rubbing in natural oils like tea-tree oil, or having hot-oil treatments before going into the sun.

- Wet hair is weaker and more vulnerable to damage. If you’re going for a swim, rinse your hair first with clean water to protect discolouration by chlorine and salt; tie back long hair to avoid tangles; and spray it with sunscreen. After swimming, rinse again with clean water and reapply sun protection.

(Health24, December 2013)

Draelos ZD. Sunscreens and hair photoprotection. 2006. Dermatologic Clinics.
Jeon SY et al. Comparison of hair shaft damage after UVA and UVB irradiation. 2008. Journal of Cosmetic Science.
Sebetic K et al. UV damage of the hair. 2008 Collegium Antropologicum.
Santos Nogueira AC and Joekes I. Hair color changes and protein damage caused by ultraviolet radiation. 2004. Journal of Photochemistry and Photobiology.

Picture: Woman with sunscreen lotion from Shutterstock

Read more:
Good care equals healthy hair
Take care of your hair
Get the best from sunscreens

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