Debunking the 'anti-sunscreen' movement: Doctors say TikTok trend is dangerous

Anti-sunscreen movement spreading online Doctors are warning against a growing online anti-sunscreen movement. Tony Grace has details.

A buff, tanned man says he has an important message from the "sun god."

"If you use sunscreen, you're literally blocking yourself from the most important aspect of health and that is light exposure," he said in a TikTok video from one of Florida's beaches.

The man with the handle "Captain Morgan" is part of the anti-sunscreen movement that claims that sunscreen can cause more harm than good. Those behind the trending term claim the chemicals in sunscreen can cause cancer and use of the product can lead to vitamin D deficiency, which weakens the immune system.

But dermatologists are sounding the alarm about misinformation from the anti-sunscreen movement, saying not wearing sunscreen is what will actually cause cancer, among other problems.

 Debunking sunscreen misinformation 

"The concern I have about this movement is that it is actually based on a lot of misinformation. So there is no solid evidence to show that using sunscreens causes cancer," Dr. Harvey Lui, a dermatologist and professor of dermatology and skin science at the University of British Columbia in Vancouver, said in a video interview with CTVNews.ca. "There are tons of information available, accumulated over many decades now, confirming that the number one cause for skin cancer is ultraviolet rays from sun exposure and also from artificial light exposure."

Dr. Linda Xing agrees, adding that sunscreens sold in Canada are carefully tested and safe.

"I think just a lot of misinformation and fear mongering out there in terms of chemicals causing harm to our body," said the dermatologist based in Oakville, Ont., in a separate video interview.

The "sun god" and other proponents of the anti-sunscreen movement say using sunscreen will deprive people of the benefits of light exposure, but Lui said the ultraviolet light from the sun is harmful when it touches the skin.

"These are the rays of the sun that have the most amount of energy. You can't see it with your naked eye and you can't really feel it," Lui said. "And because the energy of these ultraviolet rays is very powerful, they are able to go into the skin, damage your DNA molecules."

Damaged DNA molecules will allow abnormal cells to develop on your skin and potentially become skin cancer, Lui said.

"So there really isn't very much that's beneficial from ultraviolet rays," he explained. "With the one exception that ultraviolet rays can help to help your skin make vitamin D."

Addressing that claim from the anti-sunscreen movement, he said that excessive use of sunscreen may result in a decrease in vitamin D, but it won't be a problem for most people, because they can easily absorb vitamin D from their diet through foods such as fatty fish and green vegetables, as well as from supplements.

And scientific studies have not shown that using daily sunscreen leads to a deficiency of vitamin D, Xing added.

As for people concerned about chemicals in sunscreen, Lui said chemicals are everywhere, including water and food, and they're not all bad.

The chemicals in sunscreen are actually beneficial because they block the harmful UV rays, he explained.

Is not wearing sunscreen dangerous?

Instead of backing claims that sunscreen is dangerous, the doctors who spoke to CTVNews.ca said the opposite: it's skipping the sunscreen that can do harm.

Not wearing sunscreen is "very dangerous," said Xing, who regularly treats facial skin cancers at her clinic. "People forget what the alternative is. It's that people die from skin cancers induced by sun damage all the time."

Regardless of how long you plan to be outside, it's better to wear sunscreen, the doctors say, with Lui likening it to wearing a seatbelt. You may not end up needing it, but it's much safer to have it on just in case.

Excessive ultraviolet light exposure can cause sunburn in the short term, and increase the risk of skin cancer in the long term, Lui said. Just one severe sunburn can double your risk of developing skin cancer, he said.

Although physically desirable to many who associate sun-bronzed skin with looking healthy, tans are actually not an indicator of health. Instead, they indicate the skin is damaged, Lui said.

"The tan is your body's reaction to the exposure to the ultraviolet rays," he said. "What your skin is trying to do when it makes a tan is say, 'Hey, I don't like all this ultraviolet light that's hitting my skin. So I'm gonna darken my skin to try to filter out some of that ultraviolet light.'

What's more, ultraviolet rays can cause wrinkles, uneven pigmentation and sagging of the skin.

"It makes your skin look old prematurely," Lui said.

How to protect yourself from the sun

To prevent these problems, Lui recommends using sunscreen, seeking shade and covering up the skin by wearing wide-brimmed hats and long-sleeved, tight-weaved or special UV-blocking clothing.

"A simple test is hold the garment up to the light. And if you really can't see through it very much, then that means that the UV rays probably won't penetrate very far and reach your skin and cause damage," he explained.

Avoid being outdoors when the sun is most intense to minimize the chance of getting sun damage, he added.

How do you choose a sunscreen?

Sunscreens are lotions or creams containing filters that are supposed to sit on the skin like a thin film blocking the UV rays from reaching the cells of your skin, Lui said.

Any sunscreen, regardless of price or type of formula, is better than no sunscreen, dermatologists say.

Lui recommends selecting a product that is broad spectrum, which covers different types of ultraviolet light called UVA and UVB.

Choose a product that has a sun protection factor (SPF) of at least 30.

SPF 30 means it will take 30 times longer for your skin to develop a sunburn by wearing sunscreen than if you didn't have it on.

"Even higher is better," Lui said.

Look for the logo of the Canadian Dermatology Association, indicating that it has reviewed the product and endorses it, he said.

You can choose a mineral-based (or physical) sunscreen, one with organic filters (also known as chemical sunscreen), or a product with both.

"The key is use a product that you're comfortable using, that feels good on your skin and that you're willing to put on, because the only sunscreen that works is the sunscreen that lands on your skin," he said.

How to apply sunscreen

Use at least a large, bean-sized drop or an amount thick enough to leave a bit of film on top of the skin and spread it around rather than rubbing it on your face, Lui advises. You can do the same for your neck, ears and other areas of your body that will be exposed to the sun.

"And when you're finished, if you see just a little bit of white on your skin, then that's probably thick enough," he said. "Within a few minutes after you're finished putting on the sunscreen, that white film will become less noticeable."

Unless you're sweating, swimming or otherwise physically active, you won't need to reapply sunscreen if you applied it correctly in the first place, he said.

However, Xing said because sunscreen can wear off throughout the day, she recommends people reapply it every two to three hours if you will be outside for a prolonged period of time.

It's best to apply sunscreen last if you're wearing skincare like serums and moisturizers and makeup, adds Xing.