While more and more people are learning to protect their skin from the sun, very few of us protect the hair.

And if it is true that hair exposed to the UVA rays don’t get sun burned and do not originate cancer, it is also true that it can get seriously damaged. UV rays damage the hair as well as the skin. Aesthetic damage, of course, but since we live in a very physical world, where the physical aspect is very important, it may be useful to know what happens to our hair when exposed to the sun.

Which ones?

• Get yellowish

• Become dry

• Tend to freeze

• Break easily

Why does hair become yellowish?

To understand the mechanism we need to point out that the color of hair is determined by two melanic pigments:  eumelanin, responsible of brown color and pheomelanine, responsible of reddish color. The exposure to UVA rays determines a process of photo-oxidation of the pigment, which generates a new molecule, oximelanine, responsible of lightening the hair, giving the yellowish color.

The longer the exposure to the sun, the larger the quantity of oximelanine. Taking into account that the photo-protective capacity of the hair depends on the natural pigments contained in its shaft, it becomes clear that yellowing reduces the photoprotective effect.

Why does hair become dry and dull?

Shine and difficulty to comb depend on  lipids on the hair shaft. Sun exposure damages the lipids and hair will become dry and dull, subject to static electricity, easy to break when brushed and freezy.

Does sun exposed hair age?

Yes, UV rays work in two ways:

• Altering the integrity of the fibrillar protein of the cortex, responsible for the mechanic resistance of the hair shaft.

• Determining photo-oxidation of pigment and generation of oximelanine (limited photoprotecion).

How to protect hairs from UV?

To protect the skin we use a cream applied on it. Is it the same for the hair?

In fact there are shampoos, conditioners, gels and sprays containing photo-protective substances. In practice these substances are not effective due to:

• The impossibility to evenly distribute the product on each hair

• The difficulty to create a formulation that enables the photo-protective to fully adhere to the hair cuticle without making it looks dull or greasy

Among the cosmetics containing hair photo-protective substances, silicon balms, thanks to the filmogen capacity to adhere to the hair, have some, however limited, efficacy. Filmogen protective action is related to the time: the more you leave the balm on, the better its efficacy.

We can conclude saying that hair photo-protective products only offer very limited results. However, research continues and in the near future the right product may come out.

Meanwhile, let’s learn from the past: hats, scarves, umbrellas are the best protective tools for hair photoprotection. How many women use them? Not many, I’m afraid…