Sunscreen: Here’s why it’s essential

Karl Lawrence

EVERY month there seems to be a trendy new product to add to your skincare collection. Lately, a commonplace product that many people already use has taken the top spot, with everyone from dermatologists to influencers swearing by it as the number-one way to stay looking youthful through the years: sunscreen.

It’s no wonder. It’s thought that solar exposure – also known as ‘photo-ageing’ – causes up to 80% of skin ageing.

So if you’re someone who’s worried about fine lines, wrinkles and uneven pigmentation, limiting the amount of solar radiation you get is one of the most important things you can do.

There are thought to be a number of different triggers for photo-ageing. Most research has linked it to the expression of a group of proteins called matrix metalloproteinases (MMPs).

These proteins are enzymes that break down elastins and collagens in the skin’s deeper layer (called the dermis).

Elastins and collagens are responsible for the skin’s structure, strength and stretchiness.

The expression of these MMP proteins has been linked to both DNA damage in skin cells and the production of reactive oxygen species.

Reactive oxygen species are highly reactive chemicals formed from oxygen that can damage other cellular components, such as DNA and proteins.

Both of these factors are caused by too much sun exposure. Over time, this damage accumulates to cause characteristic signs of ageing.

This may explain why one study even showed people who tended to avoid the sun had significantly fewer signs of ageing compared to people who enjoyed spending time in the sun.

But it isn’t always possible to avoid the sun – which is where sunscreens help.

These products contain ingredients (such as zinc oxide) which absorb or reflect ultraviolet (UV) radiation and dissipate it safely before it can damage our skin cells.

This also reduces the cumulative dose of radiation received by the skin.

Studies have shown that sunscreens can prevent many signs of photo-ageing by tackling the triggers, with numerous studies showing they can prevent the expression of MMPs.

A study that compared the effects of using sunscreen versus a placebo on skin ageing, found that people in the placebo group had higher levels of solar elastosis (a sign of photo-ageing which causes a loss of elasticity) after two years.

An Australian study compared levels of photo-ageing in groups assigned to daily sunscreen use versus discretionary sunscreen use.

In the daily sunscreen-use group, there was no detectable increase in skin ageing over the four-and-a-half year study period, compared to the discretionary sunscreen group.

Another study has also shown daily sunscreen use for a year may reverse visible signs of ageing when assessed by a dermatologist.

CHOOSING THE

RIGHT PRODUCT

While there is plenty of evidence that sunscreens can prevent photoageing, many only block the UV range of the solar spectrum.

In the case of photo-ageing, exposure to visible radiation (particularly blue light) and infrared have all been shown to contribute to photo-ageing.

Basically, this means sunscreens can’t protect against photo-ageing entirely, but can reduce it significantly.

Some newer solar filters used in sunscreens have been developed, which can block some blue light.

Antioxidants may also protect against factors such as pollution and smoking, which are both linked to faster ageing.

Photo-ageing is a cumulative process that occurs over time.

Doing anything you can to limit exposure will slow this process, such as covering up with clothing when you go outside.

In an age of information overload, Sunrise is The Namibian’s morning briefing, delivered at 6h00 from Monday to Friday. It offers a curated rundown of the most important stories from the past 24 hours – occasionally with a light, witty touch. It’s an essential way to stay informed. Subscribe and join our newsletter community.