Our "Sun Capital" and UV rays

Going out in the sun can seem like an increasingly risky affair these days: we seem to be constantly bombarded with “shock tactic” media campaigns. Dermatologist Michel Le Maître answers our questions about suncare.

Our "Sun Capital" and UV rays

What is “sun capital”?

Sun Capital is your skin's ability to deal with environmental stresses that it is presented with, such as UV rays. Contrary to popular belief, we don’t have unlimited reserves of “sun capital” – it’s quite the opposite, in fact. Over our lifetime, our skin continues to accumulate the negative effects of the sun's rays until it reaches a point where the skin can’t absorb these rays anymore and their effects become visible, first in the form of brown spots, premature wrinkles or fine lines. When these external signs appear, it tells us that there is real damage deep down.

Do we all react to UV rays in the same way?

Unfortunately, we don’t all react to UV rays the same way. We are born with different phototypes, which have varying levels of tolerance to sun exposure. Those with dark, mixed-race or olive skin have a higher proportion of dark melanin, which gives them greater protection from UV rays. However, this doesn’t mean that they do not need to use sun protection!

Are all rays made the same?

We’ve all heard about UVA and UVB rays, but there is a common misconception that they are the same and protection against one or the other is suitable. Wrong! Both types of rays are incredibly powerful, but damage the skin in different ways. UVA rays typically cause signs of photoaging, because they deeply penetrate the skin. UVA rays are so powerful that they can penetrate through glass and clothing, so you aren’t completely protected even while indoors. On the other hand, UVB rays are mainly responsible for sunburn because they don’t penetrate the skin as deeply. It is imperative that you use a broad spectrum SPF every day that protects against both types of rays!

Does sunburn always mean that the skin has been damaged?

Absolutely! Sunburn is the result of an overdose of sun on the skin. The immediate effect is that the skin heats up and starts peeling, but the impact deep down is much more serious. Even once the sunburn has faded away, there is still underlying damage in the skin’s layers because the cells are no longer able to repair themselves properly, leading to irreversible damage.

Is it possible to tan safely?

Only if you follow the basic rules, avoiding the times of day when the sun’s rays are most dangerous and following the advice of experts. It is also important to protect your skin with a high SPF, at least 30, that protects against both UVA and UVB rays. Contrary to popular belief, this will not prevent melanin, which causes tanning, from rising to the skin’s surface.

Will a sunbed session help me tan more quickly?

Not at all! Quite the opposite: a tanning booth emits a very high dose of UVA on the skin in a very short space of time. This oxidises melanin and gives the impression of tanning after 15 minutes under the lamps, but it does not last and does not protect the skin. For the facts on sunbeds, please visit Cancer Research UK's advice page.

Michel Le MaitreScientific Advisor for Vichy Dermatology