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A tan is undoubtedly one of the ideas that unite the concept of summer in Western cultures.
This summer common denominator affects everyone more or less directly, from those who voluntarily expose themselves to the sun in pursuit of that much-desired "tan" to those who indirectly find themselves subject to greater sun exposure through outdoor work or sports activities.
What happens when we expose ourselves to the sun's rays?
First of all, it is necessary to define what the sunlight.
Sunlight
Sunlight is made up of cosmic rays, gamma rays, X-rays, ultraviolet radiation (divided into UVA, UVB and UVC), infrared radiation and radio frequency radiation, which travel through space in the form of electromagnetic waves and are differentiated on the basis of wavelength.
How much ultraviolet radiation reaches the Earth's surface?
40% of the radiation that reaches the earth is visible light, 55% infrared light, and 5% ultraviolet (or UV) radiation, which in turn is mainly made up of 99% UVA and 1% UVB (UVC is blocked by the ozone layer).
Obviously these percentages vary in relation to factors such as:
- height of the sun in the sky (time of day, season, latitude)
- altitude
- cloudiness
- wind
- geographical region
- reflective surfaces
- portion of visible sky.
So the 2 main radiations we come into contact with in the context of sun exposure are 2: UVA and UVB.
UVA radiation that activates tanning
The GRAPE come into contact with man, reaching as far as second layer of the skin: the dermis.
By crossing the epidermis, UVA rays cause direct pigmentation due to melanin maturation already present in the cells. They then reach the dermis where they disperse and are absorbed.
UVB rays and tanning
The UVB Instead, they come into contact with humans only in very small quantities getting under the skin and stopping in the epidermal layer.
In this context stimulate the production of new melanin by the melanocyte (the cell responsible for this function). Since they transport a large amount of energy, they can cause skin problems, such as erythema, photoaging, etc.
Vitamins that protect the skin
Given these aspects, it becomes very important to understand what substances our body uses to deal with this potential damage, compensating for the potential harmful consequences resulting from sun exposure.
The substances responsible for the response to oxidative stress they are different:
- Vitamin E
- vitamin A
- vitamin C
- glutathione
- Phenylalanine
- methionine
- selenium
- vitamin B10 or para-aminobenzoic acid (PABA).
Speaking of antioxidant protection It is essential to clarify that taking only one substance does not make much sense since the protective action manifests itself with a chain mechanism.
Generally the first answers can be provided by the vitamin E and/or from vitamin A (since they are fat-soluble they are deposited at the level of the cell membranes constituting the first front of the defensive response) which in turn render the free radical harmless becoming in turn radical species and potentially harmful.
Subsequently the vitamin C which undergoes a similar fate and is in turn processed by glutathione, a molecule that can then be regenerated thanks to cellular enzymatic reactions.
Beta-carotene, a precursor of vitamin A
In this context it should be pointed out that vitamin A can also be taken preferentially in the form of its precursor, the beta-carotene, which in addition to being biologically active also in this form gives rise to two molecules of vitamin A.
Furthermore, by depositing at the lipid level, these naturally “orange” colored substances contribute to giving the skin an amber tone, providing an additional protection factor.
The glutathione it turns out to be fundamental to close the circle, the problem is that it turns out to be very difficult to take orally as it would too easily undergo digestive and denaturation processes in the stomach and upper intestinal tract, it is therefore preferable to use its main precursor (the one whose deficiency would limit its production by our body): N-Acetylcysteine.
In closing the circle of the antioxidant response it is essential not to forget the role of the selenium as a major component of several enzymes responsible for replenishing glutathione.
The antioxidant response is very important but it also becomes fundamental to maintain the mechanisms responsible for melanin synthesis in full efficiency and for this reason the presence of substances such as L-phenylalanine, an essential amino acid (not produced by the body) at the basis of the melanin synthesis processes and PABA as a promoting agent of the synthesis processes that involve it.
Last but not least to mention are the cysteine and the methionine which, as precursors of numerous substances with a biological regulatory function, can intervene in maintaining full metabolic efficiency and in the related detoxification processes.
Once we know the potential problems related to sun exposure and the excellent solutions we have available, what else is left to say except: “Happy tanning everyone… yes, but in complete safety!”.
