Heat wave: are red-haired people more at risk?

Red-haired people would lack eumelanin, a genetic characteristic necessary in the repair of cells damaged by ultraviolet rays. This would greatly increase the risks for these individuals during periods of very hot weather.

It’s August and the heat wave is about to make a comeback in France. Meteo France announced on his Twitter account that a third heat wave was going to arrive in France this week, from August 3, 2022 – temperatures should once again reach locally the 40°C. The risk is obviously present, and it is necessary to adopt certain actions in order to guard against the harmful effects of heat on the body, even when you are at home.

It’s also not a legend that red-haired people expose themselves to greater danger during episodes of high heat – the main reason being the absence of eumelanin, a common type of melanin (skin pigment), and increased sensitivity to ultraviolet rays. To find out what the risks are then incurred by these people, Numerama spoke with Faïza Bossy, general practitioner and medical journalist at Horizon Santé.

“Redheads have a pheomelanin that does not really protect against ultraviolet rays”

The skin is a barrier that allows us to protect ourselves against external aggressions, such as ultraviolet rays and UVB rays. These can burn the skin and damage the DNA of skin cells, leading to serious diseases such as skin cancer. Depending on the color of the skin, and its reaction to ultraviolet radiation, we are exposed to different risks.

How does this pigmentation of the skin work, and what happens in the event of exposure to the Sun? Faïza Bossy, general practitioner and medical journalist, explains it to us: The ultraviolet rays of the Sun pass through the skin (the epidermis), then stimulate the melanocytes, defense weapons that protect us against the Sun, before of react to reduce this intrusion [ndlr : cette intrusion]. This melanin therefore makes it possible to absorb the rays of the Sun, and to effectively protect the skin against ultraviolet rays.

Depending on the skin, there are two types of melanin. First of all, eumelanin, which is a rather dark pigment (black or dark) and which effectively protects against the aggressions of the Sun — the darker the skin, the more melanin is present. And then the pheomelanin, which is much rarer and which decomposes in the face of ultraviolet rays. It is people with light complexions, such as redheads and blonds, who have it.

Faïza Bossy specifies that, for this category of people, “ you have to be very careful when exposing yourself to the sun “, before continuing that” there is a classification of skins (which is called phototype). This classification was made by [Thomas B.] Fitzpatrick in the 1950s. With regard to red-haired people, these were classified in the skin category of phototypes 1 and 2 (light skin) in terms of skin protection. This means that red-haired people are genetically low in melanin and less protected, even less adapted to the attacks of the sun and ultraviolet type B.. »

skin classification
Classification of skins by Fitzpatrick. // Source : candelmedical (cropped image)

What are the measures that people of phototype 1 and 2 should adopt?

For Faiza Bossy, “ people belonging to the light phototype must adopt strict measures against ultraviolet rays. Start by avoiding the hours of exposure to the Sun, between 11 a.m. and 4 p.m. It is also important to protect their skin with type 50 sun creams, the use of which must be repeated during the day or every time you swim in the sea. You must also always protect yourself and wear hats or glasses for swimming. eye protection, wear loose clothing for outings in town. »

Regarding the risk of heat stroke, Faïza Bossy recommends to be careful: “ The risk is obviously there. These people can blush more easily, have sunstroke and at most heat stroke. It is always important to remember, regardless of the phototype of the person: hydrate yourself, it is necessary, and also limit physical exercise. »

For further

Sunscreen... in the sun.  // Source: Pixabay (cropped photo)

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