UNDERSTANDING HOW THE SUN AGES YOUR SKIN

Exposure to the sun comes with the good and the bad. On one hand, exposure to sunlight makes us feel great, elated and illuminates our skin. Who wouldn't want to sunbathe in Ibiza? On the other hand, exposure to excessive sunlight comes along with some detrimental repercussions.  Not only does it increase the skin aging process but it can also result in skin cancer!

Dr. Manish Khanna, a Canadian dermatologist mentions that UV rays are the number one cause of skin problems; from irritation to premature skin aging. For Dr. Khanna a suntan is much more about the damage than bringing about a "healthy glow." It has indeed been proven one the greatest causes of skin cancer and skin aging is UVA and UVB rays (1, 2)!

The World Health Organization has stressed this assertion by classifying the sun's ultraviolet radiation as "carcinogenic to humans." How this happens is a mystery to many, but the one thing that is universally agreed is that ultraviolet rays are harmful to the humans and causes skin aging and accelerates the risk of skin cancer (3).

What is Ultraviolet (UV) Radiation?

Ultraviolet radiation (UV) is a type of radiation produced by the sun and some (although rarely known) artificial sources such as solariums. The sun’s radiation is regarded as the number one cause of eye damage, premature aging, sunburn, and skin damage leading to skin cancer. There are two dominant types of UV rays that affect the skin— the Long Wave Ultraviolet (UVA) rays and the Short Wave Ultraviolet (UVB) rays. Skin sunburn is caused primarily by the UVB rays. These rays are considered the deadliest as they cause the most photo-damage and lead to skin cancer (4).

UVA rays, on the other hand, penetrate deep into the skin causing rapid aging of the skin (5), albeit its contribution to sunburn and eventually skin cancer is minimal. All in all, most studies (6) have demonstrated that sun’s exposure accelerates the skin aging process by promoting the "extrinsic aging" branding it as one of the primary cause of premature aging.

How does UV Radiation Cause Skin Aging?

When UVA rays penetrate the skin to the dermis (the thickest layer of the skin), it results in the mutation and division of the skin cells producing melanin. This results in irregular pigmentation, freckles, premature wrinkles, as well as cancerous and pre-cancerous lesions. All these cause loosening (laxity) and stretching; which are the aspects of premature aging (photo-aging) (7). Cell damage as a result of excessive UV rays exposure implies that the skin cells will no longer repair or nourish themselves. This is because the UV rays not only impair the synthesis of new collagen but also breaks down its production.

The UVAs also alter the elastin fibers, the other supportive tissue apart from collagen. When those two tissues are affected, the skin loses its flexibility and elasticity which leads to loosening (8). In a nutshell, some of the consequences of UV exposure to the skin include:

• Dryness of the skin
• Freckles
• Vascular disorders
• Lack of elasticity
• Sagging skin
• Wrinkled and loose skin
• Leathery skin texture
• Telangiectasia
• Pigmentation heterogeneities
• Elastosis

How Does UV Radiation Cause Skin Cancer?

The most prevalent type of cancer in the world is skin cancer, and its numbers are worryingly hiking every single day. As aforementioned, the UVB rays are the central cause of sunburns which eventually lead to melanoma cancer. The UVA, on the other hand, penetrates the dermis causing immune suppression, photoaging, and genetic cell damage. These rays also affect the process of cell division which leads to uncontrolled growth of the epidermal skin cells leading to malignant or benign tumors. This means that even without sunburn, the UV rays can still cause skin cancer.

Ultraviolet radiation exposure has been noted as the primary cause of skin cancer. It can be experienced in three main ways; Basal cell carcinoma, melanoma, and squamous cell carcinoma. They can be broadly be classified as either non-melanoma or melanoma skin cancer. A certain study has indeed shown that 90% of non-melanoma and 86% of melanoma skin cancer is as a result of UV radiation (9).  Melanoma is the severer of the two and develops in the melanocytes. Melanomas can grow very quickly if left untreated—an aspect that highlights its severity. Besides, the moment the tumor grows through a lymph vessel, there is a higher possibility that the cancer cells will break off and rapidly spread to other body parts.

The non-melanoma skin cancers are all other cancers that occur on the skin that are not melanoma. These too can be invasive and rapidly grow across the skin's surface if not treated well in advance. But the best thing about these cancers is that they are treatable and manageable. It is important to note some of the symptoms associated with skin cancer as the treatment process is much easier during the early stages rather than during later stages. The symptoms of melanoma and non-melanoma skin cancer tend to vary. Below is a list of symptoms that indicate you either have melanoma and non-melanoma skin cancer and you should seek medical help as soon as possible;

• Brown scar lesion
• Waxy bump(s)
• Crusted surface
• A firm red nodule
• Dark lesions all over the body
• Brownish spots
• A mole that is constantly changing in size, texture or bleeds occasionally (10).

We often associate a beautiful complexion with good health, but as we’ve seen, skin color obtained from the sun—or in a tanning booth—can increase the risk of developing skin cancer or accelerate the effects of aging. The two main culprits in these two processes are UVA and UVB rays. UVA radiations penetrate deeper into the skin and are responsible for photo-aging. Conversely, UVB radiations are more lethal and are responsible for the majority of sunburns which causes melanoma—the most serious type of skin cancer. Staying protected against these two types of radiations is an absolute necessity. Besides wearing protective clothing and seeking the shades, we recommend that you protect your skin against sunburn with everyday nutrients such as green tea extracts!