We know that blue light disrupts our internal clocks, but what can it do to our skin?

Walk down the skincare aisle of any health and beauty retailer and you’ll be greeted with a bewildering array of creams and sprays, promising to protect against various threats to your skin.

You may have noticed that skincare companies claim that their products can protect you from the effects of blue light. If you hadn’t thought about blue light before, you’d be forgiven for wondering if you should be worried.

First, you need to understand what blue light is.

Visible light makes up 50% of the solar spectrum and, as the name suggests, it is the only part of light that can be detected by the human eye. The blue band of this visible spectrum has a particularly high energy level.

The longer the wavelength, the less energy it transmits. Blue light has very short, high-energy waves.

Blue light is all around you. The sun emits blue light. The same goes for fluorescent and incandescent light bulbs, cell phones, computer monitors and flat screen televisions.

What are the risks ?

There is growing evidence that blue light can have a harmful effect on the skin and eyes and disrupt the circadian rhythm (your internal clock). Generally, studies investigating the impact of solar radiation on the skin have focused on ultraviolet radiation, particularly UVB, which is responsible for sunburn.

The most commonly reported effect of blue light exposure is a significant increase in reactive oxygen species (ROS), highly reactive chemicals formed from oxygen. Too much ROS can damage your DNA and key enzymes such as those responsible for DNA repair, increasing your risk of cancer.

Our research has shown that blue light can induce pigmentation (tanning) on ​​all skin types. While many people consider a deep tan a desirable trait, it is a marker of skin damage and ROS. Other researchers found that tanning of the skin due to visible light (which includes blue light) had darker pigmentation that lasted longer than exposure to ultraviolet rays.

Our studies have also shown that blue light can activate genes associated with inflammation and photoaging (skin damage). Several studies have proven that typical sunscreens do not prevent blue and visible light damage.

Although blue light appears to be less powerful than ultraviolet radiation, this may be explained by the relatively greater amounts of blue light that reach Earth. UV accounts for around 5% of solar radiation in the UK at midday in summer. Blue light is about three times as much at 15%.

There are a few beneficial effects of blue light. It has been used to treat skin conditions including eczema, it is widely used in photodynamic therapy, which is used to treat a range of skin conditions from acne to cancer, and it stimulates the healing of sores. But the harmful effects of blue light are likely to outweigh the positive effects for healthy people.

Blue light can damage the skin, but it is less clear which sources of blue light are harmful to humans. Blue light from screens is responsible for a fraction of the doses of blue light we receive. Research has shown that device screens can increase ROS production.

However, a study by German skincare manufacturer Biersdorf found that an entire week of blue light exposure from a screen at a distance of 30cm is equivalent to just one minute of midday summer sun. Hamburg, Germany.

Another study found that blue light from screens was 100 to 1,000 times less intense than blue light from sunlight. It also did not trigger melasma, which causes patches of skin discoloration, in patients with the disease.

It’s true that we’re spending more time in front of screens than ever before, but while screens can cause harm, it’s insignificant compared to exposure to the sun.

Blue light treatment

The cosmetics industry has started to develop a wide range of skincare products that brands claim prevent blue light damage. However, there are no regulated or standardized tests to assess a product’s ability to prevent blue light damage.

Companies perform scientific tests on these products. But they can use any number of assessments in their work. This is very different from the regulations for sunscreens that claim to contain a sun protection factor (SPF). SPF testing is tightly regulated by the International Organization for Standardization (ISO). All products that claim to contain SPF are subject to an identical testing regime.

The lack of regulation for blue light claims prevents consumers from making informed choices about the level of protection offered and the differences between products.

This lack of regulation is unlikely to be harmful to consumers, but the benefits of the products may be limited.

Given the evidence regarding blue light emitted from screens, one should be skeptical of any claim that a product is necessary to prevent damage to your computer screen or phone.

Traditional photoprotection products (such as sunscreens) generally do not protect you from blue light damage. It is encouraging that the skin care industry is trying to meet this need. But it is crucial that governments take the next step in the process and develop industry-wide standardized tests.

In the meantime, it is important to remember to limit any exposure to the sun. Using sunscreens (or any product with an SPF rating) has been shown to prevent skin cancer and photoaging, and products advertising blue light protection may offer a benefit additional.

Karl Lawrence, Postdoctoral Researcher, Photobiology, King’s College London.

This article is republished from The Conversation under a Creative Commons license. Read the original article.

About Anne Wurtsbach

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