How to soak up the sun safely

As the mercury rises and the days grow longer, there’s another sure sign that summer’s here. It’s the abundance of sunscreen and sunblock skin products flying off supermarket, pharmacy and health-store shelves.

It is well known that sunlight can be as healing as it is harmful. But can these products, with their widely (and wildly) differing ingredients and sun protection factors (SPFs), really maximise benefits, while minimising serious risks of exposure to the sun’s ultraviolet (UV) rays? And do you always need them when venturing outdoors even if the sky is overcast and no matter your skin colour?

Yes, to all of the above, says Cape Town dermatologist Dagmar Whitaker.

There is no such thing as “safe sun tanning”, if by that is meant voluntary unprotected exposure to sunlight, she says. There is also no such thing as a “safe skin tone” for sun exposure.

Whitaker is in private practice in Cape Town and is president of the SA Melanoma Society, vice-president of the World Melanoma Society and immediate past president of the SA Dermatology Association. She is also a member of the national research team of dermatologists, biochemists and environmental and public health scientists in SA that spent a year reviewing the evidence on benefits versus risks of sunlight and optimum protection methods.

The team has published the first comprehensive set of guidelines to safe sun exposure for the SA population in the International Journal of Dermatology in December 2023. Lead author of the team is Bianca Tod, a specialist dermatologist at Tygerberg Hospital in Cape Town and a senior lecturer at Stellenbosch University’s faculty of medicine and health sciences.

The researchers have addressed the many myths and misinformation about optimum sun protection methods. Their messages are clear: everyone needs protection from the sun, regardless of skin tone. When spending extended time outdoors, optimum sunscreen products are broad-spectrum: against both UVA and UVB sunrays and with an SPF 50.

SPF 50 is a time factor for longer, not stronger, protection, Whitaker says. Even with the gold standard of an SPF 50, you will acquire more melanin (colour) than individuals who don’t expose themselves much to sunlight.

“That’s due to the fact that no sunscreen offers complete protection,” she says.

Sunscreen products are just one ingredient on a menu of sun-protection methods. Other methods include wearing protective clothing, wide-brimmed hats and sunglasses, staying in the shade and avoiding peak hours of sunlight.

In the southern hemisphere, UV rays are strongest between 10am and 4pm. And always keep in mind, says Whitaker, that the sun “absolutely has as many beneficial as harming effects”.

One of the major benefits of even moderate sunlight exposure (and while wearing a sunscreen) is vitamin D production, she says.

Research shows that vitamin D is essential for bone health, immune function, regulating the body’s “internal clock” (circadian rhythms) and as a mood boost. It also helps to lower blood pressure, which reduces the risk of cardiovascular disease, and to counteract myopia (short-sightedness).

Moderate sun exposure is shown to be key to maintaining vitamin D levels crucial for health. This “by no means translates into going into the sun unprotected — even for short periods”, Whitaker says. Research states clearly that the use of sunscreen does not prevent the production of vitamin D.

The biggest risk from excessive or unprotected sunlight exposure is skin cancer. The incidence of skin cancer is rising worldwide, and SA is no exception, Whitaker says.

“Other African countries are worse off than SA, because they often don’t even have cancer registries.”

Long-term exposure to sunlight causes melanoma, the deadliest of all skin cancers, she says. “It spreads rapidly and if missed or left untreated, it can metastasise and kill the patient.”

SA’s abundant sunshine throughout the year, its high, ambient UV concentration has contributed to an incidence of malignant melanoma in fair-skinned people “almost equal to that in Australia”.

While melanoma is more common in fairer skin, those with darker skin are not immune from serious risk. People tend not to think of melanoma risk for those with dark skin, Whitaker says. The diagnosis can then be missed, patients present late and have a much worse prognosis.

Other skin cancers directly related to sun exposure are basal cell carcinoma and squamous cell carcinoma that are “100% related to accumulative sun exposure”, she says.

These cancers cannot spread easily to other parts of the body, but they “grow relentlessly and leave a hole in your skin if not removed surgically”.

Other risks from unprotected sun exposure include “photoageing” — long-term, premature wrinkling and other skin changes and vision damage. Excessive sun exposure contributes to cataracts, macular degeneration and photokeratitis (sunburn of the cornea).

Choosing a sunscreen or sunblock can be challenging.

“There are as many sunscreens as toothpastes,” Whitaker says. “Requirements differ according to need. For example, someone who swims needs a different sunscreen compared to a cyclist, a runner or someone mainly going out for lunches.”

Just as you don’t choose a toothpaste according to what you eat, Whitaker advises that you choose a product with an SPF 50 and use it summer, winter, sunshine or rain.

Sunscreen products are best viewed as medication, not just a cosmetic with unregulated ingredients that keep changing, she says. Fortunately, these products have improved significantly over the past decade.

An article in the SA Medical Journal in 2012 noted that local sunscreen manufacturers had begun “hastily reformulating their products following confidential tests commissioned by the National Cancer Association of SA (Cansa)”. Tests showed that most of these products offered suboptimal protection.

“You are likely to be safe if you go for European products,” says Whitaker.

These are tested by the Colipa board. The board is the governing body of the European Cosmetics and Perfumery Association, now known as Cosmetics Europe. Colipa is a European testing sequence equal to that of any other medication, she says.

The moment you venture into untested products, including so-called “natural” sunscreens and sunblock creams, the scientific heat is on.

“Natural” sunscreens can be effective and safe when formulated correctly — especially those with non-nano zinc oxide or titanium dioxide. However, research shows that they are not inherently safer than conventional sunscreens.

A major problem is that the term, “natural”, is not strictly regulated in many countries, including the US, EU, UK and SA. Products labelled as “natural” can contain unsafe synthetic or chemical ingredients and mislead consumers with unscientific marketing claims.

Whitaker is no fan of so-called “tanning pills”. Ingredients include betacarotene, zinc and some B vitamins that claim to allow for faster tanning with a “deeper colour”.

Tanning deeper or faster means that you activate the body’s melanocyte cells to produce more pigment to protect the skin from sun damage, she says. That can be a “very bad idea if you happen to have a cancer cell sitting there, waiting, as you will activate that as well”.

“Self-tanning” products, also called “sunless tanners”, can be safer options, she says. These products offer a cosmetic alternative to achieve a bronzed or tanned look without direct exposure to harmful UV rays from the sun or tanning beds.

They work by temporarily colouring the outermost layer of your skin. Their key ingredient is usually dihydroxyacetone (DHA), a colourless sugar that interacts with dead skin cells on the surface of the skin. When applied to the skin, DHA reacts with amino acids in the dead cells of the stratum corneum (the outermost skin layer).

This chemical reaction causes the skin to darken temporarily, creating a tanned appearance within hours. The colour typically lasts between three to seven days, gradually fading as dead skin cells naturally shed.

If you use self-tanners, you’ll still need to wear sunscreen when going outdoors because these products provide no protection against UV radiation.

For the rest, it is possible to tan safely and achieve benefits from sunlight while reducing risks, Whitaker says. That’s if you acquire a tan slowly by using daily protection (sun avoidance, sun-protective clothing and sunscreen on unprotected areas), avoiding the hottest parts of the day, and then achieving your desired colour without going a shade of red.

“Tanning through burning, with skin going red first, then brown, always increases cancer risk,” she says.