Q&A: Under the blaring sun this week? Here’s how sunscreen actually works, and which kind might be best for you

With few clouds in the sky during this week’s heat wave, sunscreen is more important than ever.

“Sunscreen not only protects skin in the long term from skin cancer, but it also prevents extreme burns,” said Kelli Hawkins, Spokane Regional Health District spokesperson.

If skin is sunburned, it can increase the likelihood of heat exhaustion because the body isn’t able to properly regulate temperature, Hawkins said.

Dr. Courtney Gwinn, a dermatologist at Advanced Dermatology and Skin Surgery in Spokane Valley, said exposure to the sun can cause major long-term health problems, as well as cosmetic issues.

“We see really big skin cancers here at Advanced Dermatology and Skin Surgery, and those skin cancers stem from sun exposure you get when you’re 18 years old, to the sun exposure you’re getting now. And so preventing yourself from getting those sunburns, getting those tans will decrease your risk of getting those big skin cancers in the future,” Gwinn said.

Here are some of Gwinn‘s answers to our questions about sunscreens and skin care.

Why is it important to use sunscreen, and what are the benefits?

Using sunscreen decreases the likelihood of tanning and getting sunburned . The color change from sunburns and tanning shows that the harmful ultraviolet rays are penetrating the skin, which can cause mutations that may lead to skin cancer and premature aging.

Sunscreen can prevent those mutations that cause skin cancer. “Sunscreen is integral in that process,” Gwinn said.

What type of sunscreen works best?

There are two types of sunscreens: mineral and chemical. Gwinn prefers mineral sunscreens. “Typically, we recommend sunscreens that include either zinc oxide or titanium dioxide,” all of which are found in mineral sunscreens, Gwinn said.

What ingredients should we look for? What do they mean?

Zinc oxide, found in mineral sunscreens, can protect skin from the whole ultraviolet spectrum, but it breaks down in sunlight, so titanium dioxide is added to make the sunscreen more stable in sunlight. Titanium dioxide also increases protection from ultraviolet B rays, which have a shorter wavelength.

For chemical sunscreens, manufacturers usually include ingredients such as oxybenzone, octinoxate and avobenzone, which are all great for protection against the sun. But each chemical only protects you from a specific part of the ultraviolet spectrum, Gwinn said.

Are chemical sunscreens safe to use?

Many people use chemical sunscreens to avoid the white cast that comes with using mineral sunscreens, but chemicals in the non-mineral sunscreens may not be safe for skin or the environment, Gwinn said.

“We’re actually absorbing 10 to 15 times the amount that we once thought into our blood when we apply those sunscreens to our skin,” she said.

Common chemicals like oxybenzone are absorbed into the skin up to 15 times the level of absorption recommended for that chemical by the Food and Drug Administration. There’s a concern that those sunscreens can increase the risk of things like endometriosis and heightened estrogen levels, Gwinn said.

Gwinn advises caution when using these chemical sunscreens, and to not use them for children under the age of 1 and for individuals who have had estrogen-sensitive cancers like breast cancer.

How is chemical sunscreen bad for the environment?

Hawaii and some countries have banned the use of chemicals like oxybenzone and octinoxate, as these chemicals have been shown to be toxic to coral reefs, Gwinn said.

How often should sunscreen be reapplied?

“We would highly recommend people wear sunscreen consistently, particularly between the peak hours of 10 a.m. and 2 p.m., with reapplication every two hours,” Gwinn said.

It’s especially important when out on a boat, in water or somewhere the sunscreen can be washed off to reapply, Gwinn said.

Do higher temperatures worsen sunburns?

With it being peak summer, the amount of sun exposure people outside get is higher, but temperatures don’t correlate with getting worse sunburns, Gwinn said.

How can someone prevent the white cast of mineral sunscreens? What are facial sunscreens?

Mineral sunscreens without a white cast are typically facial sunscreens. These sunscreens or tinted sunscreens have micronized the minerals in the sunscreens to make the white sheen not visible. Sometimes they also have ingredients that are less likely to block pores. They tend to be a bit more expensive.

“They work fantastically, and I would highly recommend them,” Gwinn said. They can also have other ingredients added like hyaluronic acid that helps with moisture or vitamin C that helps with anti-aging. Body sunscreens can be used on the face, but the ones marketed for the face are more “cosmetically elegant,” Gwinn said.

What SPF number works, and do cosmetic sunscreens work?

“We always recommend a sun protection factor 30 or greater for optimal protection,” Gwinn said. Makeup products that offer SPF tend to not offer more than 15 SPF. That is not enough. There are tinted sunscreens made with enough protection, but if using regular makeup or makeup without enough SPF, “we typically recommend layering a base of SPF 30 sunscreen with your makeup,” Gwinn said.

When should a person use sunscreen?

“Ultraviolet rays come in contact with your skin year-round, making sunscreen important even when it’s cloudy,” Gwinn said.

What other conditions can be prevented by using sunscreen?

“Melasma is a condition where you get hyperpigmentation in response to the sun, and sunscreen is one of the key ways to avoid getting and worsening melasma,” Gwinn said. Gwinn recommends tinted mineral sunscreens for this condition, as they can block the visible light in addition to ultraviolet rays.

What other ways can people get protection from the sun?

Using a vitamin C serum before your facial sunscreen can help filter environmental and UV components from the skin, and help with anti-aging and hyperpigmentation . In Wearing a wide-brimmed hat and sunglasses and using an umbrella or other shade-providing gear can help protect from exposure.

What sunscreens do you recommend?

Some of Gwinn’s personal favorite body sunscreens are EltaMD UV Sport sunscreen, which can be bought online, and Sun Bum mineral sunscreens, which can be bought in stores. For face coverage, her favorites are tinted SkinCeuticals sunscreen and tinted ISDIN sunscreen.