How the Sun affects our skin and hair
Many people believe that the natural photoprotection products of the body are enough and forget about their hair, which suffers a prolonged and intense attack from the Sun’s rays when they are sunbathing.
If the hair has had prolonged exposure to the Sun, UVA and UVB rays can damage the outside cover of the hair, called the cuticle.
How does the Sun affect our hair?
Hair constantly suffers from a series of environmental aggressions such as in sea water or swimming pools as well as environmental pollution in cities, but what produces the greatest alteration is solar ultraviolet radiation. The effects are aggravated by dyed hair because keratin can be modified under the effects of the heat of the Sun’s ultraviolet rays, UVA and UVB.
There are three effects of ultraviolet radiation on hair:
A. Formation of free radicals.
Hair’s amino acids such as cystine, tyrosine, phenylalanine and tryptophan absorb ultraviolet radiation and form free radicals, thus hair’s disulfide bond can break. The result is hair damage- split ends are created and hair becomes frizzy, dry and loses volume.
On light or blonde hair discoloration occurs due to a photo-oxidation of the hair’s amino acids, tyrosine, tryptophan, cystine, histine and proline.
On brown hair, the discoloration occurs due to the photo-oxidation of melanin.
C. Hair Fiber alterations.
The hair damage from sun exposure is as severe as the damage to skin, and is related to the length of the exposure to solar radiation. The hair fiber, due to ultraviolet radiation, becomes brittle and prone to frizziness and split ends, while UVA and UVB radiation alter hair color pigments. The Keratin hair or cuticle is the outermost part of the hair and therefore it is the first thing that is affected by solar radiation- it opens, loses its protection and the innermost hair layer’s breakage begins.