using both is the true “total shield”

In recent years we have seen how active cosmetics have put vitamin C at the center of all morning routines. Its fame is justified, but it has brought with it a dangerous myth when it suggests that it can be a solar shield in itself. But the reality is that, although it is true that it provides good additional antioxidant protection against sun damage, under no circumstances does it replace traditional sun protection.

Vitamin C. The first concept we must internalize is that vitamin C does not block UV radiation the way a chemical or physical filter does. In fact, it has no measurable sun protection factor on its own.

Its true positive effect lies in its antioxidant mechanism, which is responsible for neutralizing free radicals that are generated by UVA, UVB and IRA radiation. By doing this, vitamin C manages to reduce oxidative stress and prevents part of the DNA damage, such as thymine dimers, lesions closely associated with skin cancer.

The investigation. Scientific literature has been demonstrating for years that true protection occurs in the synergy of several factors. One of the first studies dates back to 1996, where was demonstrated that vitamin C provides additive protection against UVB damage when combined with a specific sunscreen. But this same study observed that the combination of vitamins C and E was even more protective, and that by adding a UVA filter, much greater protection was obtained.

But it does not stop there, since this same team published a second study in 2003 where they saw that the combination of 15% vitamin C and 1% vitamin E applied to the skin for four days managed to multiply approximately by four the antioxidant factor.

Infrared light. Given all this, a question that may be obvious is that, if there are already sunscreens with a protection factor SPF 50, why is it necessary to combine it with antioxidants? And the answer lies in the spectrum that conventional creams do not cover.

A trial here found that a sunscreen with SPF 30 alone did not protect against infrared radiation A. However, by applying the same protection factor enriched with an antioxidant cocktail, it was possible to significantly reduce the overexpression of factors related to skin photoaging.

The consensus. Despite the overwhelming benefits of antioxidants, medical guidelines indicate that there is no evidence that using a vitamin C serum instead of sunscreen is positive. In this case, the American Academy of Dermatology insist in which sunscreen is essential, and antioxidants can be a positive addition, but never a substitute.

But in addition, for all this “added protection” to be real, scientific evidence demands two requirements: it must be used in conjunction with a broad-spectrum protector and the vitamin C formulation must be stable, requiring an adequate pH, protection against oxidation and, often, the combination with vitamin E or ferulic acid.

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