Battling social media misinformation around sunscreen

Claims about sunscreen’s dangers are targeting young people, and while pharmacists know evidence shows them to be safe and effective, many in the Australian community do not.

The anti-sunscreen movement has picked up speed this year, thanks to the spread of misinformation by influencers on TikTok and other social media platforms. Popular podcasters Joe Rogan and Kristin Cavallari have also led discussions making misleading claims about risks of sunscreen.

Myths about sunscreen’s dangers are fueled by a broader decline of trust in science, said Professor Rachel Neale, Senior Group Leader at the QIMR Berghofer Medical Research Institute.

‘People who are good at influencing others are getting their message through because of this loss of trust in authority and science,’ she said.

While this distrust predates COVID-19, the pandemic accelerated skepticism – particularly around the mass rollout of an ‘untested’ vaccine. 

‘We’re [also] seeing it in things such as the debate about fluoride in the US,’ she added.

While the fears around sunscreen lack concrete evidence, they are often based on a grain of truth albeit taken out of context.

Prof Neale walks through the key myths that are doing the rounds, and how pharmacists can help to debunk them.

Myth: sunscreen causes skin cancer

One prevailing theory circulating on social media is that sunscreen itself causes skin cancer. 

‘In observational studies, people are asked “how often do you use sunscreen?”,’ she said. ‘And people who say they use sunscreen more are at higher risk of skin cancer.’

But there are a few important caveats about regular sunscreen users that give these findings context.

‘Sunscreen users are often paler and burn more easily,’ said Prof Neale.

‘People with very pale skin wearing sunscreen are still at higher risk than someone with more deeply pigmented skin who doesn’t use sunscreen.’ 

Sunscreen use also tends to encourage prolonged sun exposure.

‘Sunscreen allows some UV radiation through. If people are using sunscreen to avoid getting sunburnt, their skin will still receive some UV radiation. And even small doses of radiation can cause harm for people with pale skin,’ she said.

‘Importantly, we have definitive evidence from randomised controlled trials (which overcome the problems of the observational studies) that regularly using sunscreen reduces the risk of skin cancer.’

Myth: oxybenzone is a toxic hormone blocker

Oxybenzone, an active ingredient in chemical sunscreens, absorbs both UV-B and short-range UV-A rays.

But there have been concerns aired on social media that oxybenzone is in fact toxic, acting as a ‘hormone blocker’ or ‘endocrine disruptor’.

This may be particularly worrisome for women who are trying to conceive or during perinatal, perimenopausal or menopausal stages.

Yet these concerns are harder to dismiss, acknowledged Prof Neale.

‘Animal and in vitro studies show some evidence that sunscreen ingredients can affect cell behaviour,’ she said. ‘But the findings are inconsistent – some mouse studies show effects, while others don’t.’

However, the United States Food and Drug Administration (FDA) has conducted studies revealing that certain chemical sunscreen ingredients can be absorbed through the skin into the bloodstream at levels exceeding 0.5 ng/mL. 

‘[This absorption occurs] at a level where the FDA has recommended that further investigation is warranted,’ said Prof Neale.

Yet, she emphasised that ‘this is not evidence of harm’. 

‘The authors of that study recommend that people continue to use sunscreen because we know that sunscreen is beneficial, and there is no convincing evidence of harm,’ she said.

The Therapeutic Goods Administration regulates primary sunscreen products, and some secondary sunscreens, for use in Australia, which should provide users with confidence that the ingredients and formulations are safe and effective.

Myth: sunscreen reduces vitamin D levels

Yet another social media gripe is that sunscreen reduces vitamin D levels – which is important for musculoskeletal health and has been linked to autoimmune conditions such as multiple sclerosis.

While this claim is not entirely a myth, its significance is often overstated.

Given sunscreen works by blocking or absorbing UVB radiation, which is responsible for triggering vitamin D production in the skin, sunscreen should in theory lower vitamin D synthesis.

However, there is little evidence to suggest this occurs in real-life settings.

For those with very pale skin who are advised to limit sun exposure with clothing and sunscreen, there’s a way to both ensure vitamin D levels are maintained and reduce the risk of skin cancer.

‘Vitamin D supplements are a cheap and effective substitute for sun exposure as a way of maintaining adequate vitamin D status,’ added Prof Neale.

When in doubt, suggest a mineral alternative

For those concerned about chemical absorption, the FDA has classified two mineral sunscreen ingredients – zinc oxide and titanium dioxide – as ‘generally recognised as safe and effective’.

This could particularly assuage parents who are concerned about exposing young children to ingredients that are claimed to be toxic, said Prof Neal. 

Mineral sunscreens come in a thicker texture and work immediately by reflecting UV rays. While non-irritating and suitable for sensitive skin, they can leave a white cast on the skin and are harder to blend.

Chemical sunscreens absorb UV rays, taking about 20 minutes before it starts working. While available in an easily blendable light weight texture, some formulations may irritate sensitive skin.

‘A while ago, there were concerns about nanoparticles in the mineral sunscreens, but that’s been pretty thoroughly debunked.’

Given the mineral varieties work as a physical UV blocker, they won’t appeal to everyone.

‘They don’t spread as easily or feel as nice on the skin,’ she said. ‘But kids probably don’t mind as much about the feel of it.’

Leave judgement at the door

With pharmacists being key providers of sun protection advice, it’s important to take a non-judgmental approach when people express concerns about sunscreen – particularly when discussing use in young children.

But it’s important to emphasise that there is no convincing evidence that sunscreens cause harm, while there is strong evidence to suggest sunscreens are beneficial. 

‘It’s really important that pharmacists support people to continue using sunscreen and to find a sunscreen that works for them – while also recognising that sun protection does not just mean sunscreen,’ said Prof Neale.

‘They should support people to use the entire suite of sun protection measures, such as putting on clothing, avoiding activities during peak UV times if possible, wearing a broad-brimmed hat and seeking shade.’

Move past the myths, focus on the benefits

While it’s important to get the message across about sun safety, Prof Neale said conversations about potential harms of sunscreen shouldn’t be given too much oxygen.

‘We should not be talking about it as much as we have started to, because it’s almost like giving people a license to worry about it,’ she said. ‘There is no doubt that the sun causes skin cancer, and we have an epidemic of it.’

Skin cancer on the face is quite common, and while a broad-brimmed hat provides a good level of protection, it doesn’t prevent harm from reflected light off the ground.

‘It’s really important we emphasise that regular sunscreen use can prevent this,’ said Prof Neale.

Talking about the benefits of sunscreen, rather than the harms, is the best way to dispel these myths.

This includes preventing photoaging and actinic keratosis – which may turn into skin cancer.

‘We spend a fortune on treating sunspots and the treatments can be painful and unpleasant,’ she said.

‘One day, maybe we’ll find out that there is some confirmed harm from sunscreen, but I’ll be very surprised.’