Sun protection and how to prevent photoageing of the skin

For many years, sun protection was seen almost exclusively as a summer recommendation. Applying sun cream on the beach, avoiding sunburn and repeating the routine throughout the holidays seemed sufficient. However, modern dermatology has profoundly changed that view. We now know that the relationship between the sun and the skin is far more complex, and that much of the damage to the skin occurs silently, cumulatively and progressively, long before it becomes visible.

“Ultraviolet radiation causes cumulative cellular changes even when we do not see any immediate lesions. The skin has a biological memory and sun damage eventually becomes visible as the years go by,” explains Dr Javier Pedraz Muñoz, head of the Dermatology department and director of the Aesthetic Dermatology Unit, which takes a holistic approach to skin health, photoageing and medical-aesthetic skin treatments.

Ultraviolet radiation does not only have an effect when the skin reddens. In fact, many of its most significant effects occur without causing immediate symptoms. Every exposure leaves a microscopic mark that the body continually tries to repair. Over the years, this mechanism becomes less effective and signs begin to appear that we usually attribute solely to natural ageing: dark spots, loss of elasticity, deep wrinkles or changes in skin texture.

“In our practice, we very frequently see patients concerned about dark spots or facial ageing that are actually linked to cumulative sun exposure over many years,” says Dr Pedraz. “The sun leaves a mark on the skin, and that mark eventually becomes visible.”

For this reason, sun protection is no longer considered merely a cosmetic measure. It forms part of medical and dermatological prevention.

The sun does not affect all skin in the same way

Not all skin types respond in the same way to solar radiation. The amount of melanin, the tendency to burn, skin thickness and the ability to tan all significantly influence an individual’s risk.

Very fair skin tends to have a lower natural capacity to protect against ultraviolet radiation. People with this skin type burn easily, tan very little and develop signs of actinic damage or photoageing sooner.

However, darker skin types are not without risk either. Although they contain more melanin and offer some natural protection, they can also develop dark spots, skin ageing and skin cancer.

“One of the most common misconceptions is to think that people with dark skin do not need sun protection,” explains Dr Javier Pedraz. “What happens is that sometimes the damage appears differently or is diagnosed later.”

What actually happens when solar radiation reaches the skin

Sunlight contains different types of radiation. From a dermatological point of view, the most important is ultraviolet radiation, which is mainly divided into UVA and UVB.

UVB rays are responsible for classic sunburn. They act on the outermost layers of the skin and cause direct damage to cellular DNA.

UVA radiation, however, penetrates more deeply and is primarily involved in skin ageing and cumulative oxidative damage. Furthermore, it partially passes through clouds and even glass, which explains why there is significant sun exposure even in everyday life.

“Many people associate sun damage solely with a day at the beach,” says Dr Pedraz. “But much of the cumulative exposure occurs whilst walking down the street, driving, or through repeated brief exposures over the years.”

In recent years, dermatological research has broadened the traditional approach to sun protection. We now know that skin damage does not depend solely on UVB radiation.

In addition to UVA radiation, which is implicated in skin ageing, other factors such as visible light, infrared radiation and even environmental pollution play a part in processes of oxidative stress and collagen degradation, contributing to photoageing. This concept of environmentally-induced skin ageing has been extensively described in recent scientific literature.

What does SPF 30 or SPF 50 actually mean?

Few abbreviations cause as much confusion as SPF, or sun protection factor. Many people interpret the number on a sunscreen as an ‘absolute level’ of protection, but the actual meaning is more complex.

SPF measures a sunscreen’s ability to reduce the effect of UVB radiation, that is, the type primarily associated with sunburn.

In theory, an SPF of 30 means that it would take the skin approximately thirty times longer to develop erythema or a sunburn than if it were unprotected. An SPF of 50 would increase that tolerance time against UVB radiation even further.

However, this explanation should be interpreted with caution as it is based on highly controlled laboratory conditions. In practice, factors such as the amount applied, sweat, water, sun intensity and skin type all play a role.

Furthermore, the difference between high SPFs is not as great as many people imagine. An SPF 30 filters out approximately 96–97 per cent of UVB radiation, whilst an SPF 50 filters out around 98 per cent.

“The main problem is not usually using a low SPF,” explains Dr Javier Pedraz, “but applying far less than the required amount or thinking that a high SPF allows you to spend unlimited time in the sun.”

The evolution of sunscreens

Sun protection has evolved enormously in recent years. The old, thick and uncomfortable sunscreens have given way to much more sophisticated formulations.

There are now sunscreens tailored to different skin types, dermatological conditions and lifestyles. Some contain antioxidants, protection against visible light or specific technologies for patients with melasma, rosacea or oily skin.

From a technical point of view, sunscreens are generally divided into physical and chemical types, although many modern formulations combine both mechanisms.

Mineral filters, such as zinc oxide or titanium dioxide, reflect and scatter some of the radiation. They are particularly useful for sensitive skin, children or certain dermatological procedures.

Chemical sunscreens absorb ultraviolet radiation and convert it into less harmful energy, allowing for lighter and more cosmetically appealing textures.

“The best sunscreen is not necessarily the thickest one, nor the one that leaves a film-like sensation on the skin,” says Dr Pedraz. “The best sunscreen is the one that the patient can use correctly and consistently every day.”

Sun protection does not depend solely on sun cream

One of the most common mistakes is to reduce sun protection solely to the use of sun cream. From a dermatological point of view, the most effective measure remains limiting the amount of radiation that directly reaches the skin.

That is why so-called physical sun protection continues to play a vital role.

Clothing acts as a genuine barrier against ultraviolet radiation. Dense fabrics or those specifically designed with UV protection can block a very significant proportion of solar radiation.

Wearing wide-brimmed hats also provides significant protection for particularly vulnerable areas such as the face, scalp, ears and neck.

Approved sunglasses also help to protect delicate eye structures from cumulative ultraviolet damage.

In addition to all this, it remains essential to avoid the middle of the day, particularly between 12 noon and 4 pm, when radiation is at its strongest.

“Effective sun protection never depends solely on sun cream,” summarises Dr Javier Pedraz. “It also involves understanding how to expose ourselves to the sun and how to reduce cumulative damage.”

Photoageing: when the sun accelerates skin ageing

Photoageing refers to skin ageing caused by cumulative sun exposure.

Various studies estimate that up to 80 per cent of visible signs of facial ageing may be linked to environmental factors, particularly solar radiation.

“Many patients think that wrinkles or dark spots are solely a consequence of ageing,” explains Dr Pedraz. “But in reality, a large proportion of these changes are due to cumulative sun damage over the years.”

Ultraviolet radiation causes oxidative stress, leading to the breakdown of collagen and elastin. As a result, wrinkles, loss of firmness, dark spots and a deterioration in skin quality appear.

A study published in the *American Journal of Clinical Dermatology* concludes that the continued use of broad-spectrum sunscreens is associated with a significant reduction in signs of photoageing, particularly in terms of dark spots, skin texture and fine lines.

Clinical evidence agrees that UVA radiation plays a key role in skin ageing, as it penetrates deep layers of the skin and promotes the progressive breakdown of collagen and elastin.

As Dr Javier Pedraz explains, “skin ageing is not just a matter of age, but largely a result of cumulative sun exposure over time”.

Sun protection and skin cancer: a direct link

The rise in the incidence of skin cancer in recent decades has made sun protection a health priority.

Melanoma remains the most aggressive form of skin cancer, although basal cell and squamous cell carcinomas are much more common. All share a key risk factor: cumulative exposure to ultraviolet radiation.

Prevention does not depend solely on the use of sun cream. It also involves changing sun exposure habits, avoiding repeated sunburn and learning to monitor one’s skin.

The appearance of new lesions, changes in existing moles, wounds that do not heal or spots that gradually change in appearance should prompt a dermatological assessment.

 Protecting your skin does not mean avoiding the sun

Photoprotection does not mean living away from the sun or developing a fear of sun exposure. The aim is to learn to interact with it in a safer, healthier and more mindful way.

Current scientific evidence clearly shows that consistent photoprotection over time not only reduces the risk of skin cancer, but also helps to preserve skin quality and prevent much of the premature ageing associated with solar radiation.

This content is for information and educational purposes only and is not a substitute for an individual medical assessment.

The information in this article is provided for general awareness and does not replace an individualised medical assessment.