Reacción a "TikTok videos that criticise sunscreen are minority, but attract disproportionate engagement"

I agree generally with the overall findings: 

Content containing misleading and contrarian ideas gets greater audience interaction, due to emotional impact, which boosts its virality.  

Sunscreen health misinformation is a minority of content on TikTok, especially content that does not contain any positive messaging about sunscreen. 

Despite being a minority of content, it’s influential - misinformation doesn’t have to be overwhelming to be of concern, and repeated exposure increases the perception of its accuracy among all audiences. 

In my experience debunking sunscreen misinformation on social media over the past 10+ years, these have been some of the most significant challenges. Social media algorithms currently incentivise attention-grabbing content; there are few repercussions for spreading misinformation, and most people struggle to critically assess scientific claims. 

But I think sunscreen misinformation resonates with a wider audience than the authors suggest, and may be more widespread than their results indicate: 

The methodology used in this study may have misestimated the prevalence of misinformation on TikTok. The importance of hashtags in the TikTok algorithm has been declining since perhaps 2022, so using hashtags to find videos may not accurately reflect the misinformation that users are seeing. In my opinion, this highlights the need for social media platforms to provide better data for researchers. 

The idea that sunscreen can be harmful to health was already very widespread before TikTok, so I think this content would be influential for a broader audience than the authors seem to suggest.  

I would go further than the authors on their finding that sunscreen misinformation has a disproportionately heavy impact. Given the widespread misconception that sunscreen is harmful to health, I think subtler types of sunscreen misinformation can increase the illusory truth effect.  

In my opinion, content that is overall positive about sunscreen but contains this more subtle misinformation is a greater concern. It can be more persuasive for less conspiratorially-minded audiences, as it is often posted by perceived authorities (e.g. medical doctors, scientists), and is less likely to be immediately dismissed (it contains a nugget of truth). Authority bias is extremely powerful on social media, especially if it appears to be endorsing a conspiratorial belief - this has been the 'stickiest' misinformation in my experience. 

It is rare that I read an article on sunscreen that does not contain at least one piece of sunscreen misinformation, including those that claim to be busting sunscreen myths, and including papers in the peer-reviewed literature. Many internet sources cite the introductions of peer-reviewed articles as evidence, and the vast majority of the general public views any 'peer-reviewed' text as authoritative, so I think more careful wording of the introduction could avoid perpetuating some common myths further: 

Benzene contamination isn’t really a legitimate health concern, even for the 'few specific products' that were recalled: 

This issue was raised and promoted in 2021 by Valisure, a company with undisclosed conflicts of interest (e.g., working closely with class action lawyers), and a history of inaccurate testing that has been called out in the peer-reviewed literature by regulatory agencies. The FDA has also flagged that Valisure's benzene measurements are 'much higher' than they should be (they are the 'third party' in this statement). 

Many dermatologists felt it was a legitimate concern, and spread this widely on social media - in my opinion, Valisure targeted dermatologists with their messaging, knowing that they didn’t have the relevant expertise to critically evaluate their findings. 

The PLOS Digital Health article cites 2 sources on benzene that are primarily based on commentary from dermatologists. Refs 30 and 31 both uncritically repeat Valisure’s measured benzene levels. They contain other misinformation in them as well, e.g. ref 31 states 'If you want to avoid chemicals altogether, Dr Bullard suggests a mineral sunblock that’s made with titanium dioxide or zinc oxide.' 

A later analysis found no link between sunscreen use and blood benzene levels, which is what would be predicted even based on Valisure's likely-inflated numbers. 

This topic has been the focus of several very viral pieces of sunscreen misinformation that mainstream audiences seemed to find convincing, e.g., announcements about the original finding from dermatologists or Australian comedians - this was far more popular on Instagram, which could also indicate this misinformation resonates with an older audience as well. 

Mineral sunscreens don’t 'block' UV rays all that differently from 'chemical' sunscreens - both types primarily work by absorbing and deactivating UV rays, so their mechanism of action isn’t a legitimate reason for choosing one over the other. 

Some of the videos containing this may have been miscounted in the analysis, as content distinguishing the two sunscreen categories often relies on an implied premise that chemical sunscreens are harmful in some way (but I'm unsure if this would've changed this study's reported percentages by much). 

This myth has been the basis of many other myths that impact consumer sunscreen choice ('family tree' of myths arising from this). It also goes against the dominant advice of 'the best sunscreen is the one you prefer', leading to poor adherence to sunscreen use, as mineral sunscreens are aesthetically unacceptable to many people. 

This myth is extremely widespread, and appears in many of the references listed in the PLOS Digital Health article from reputable-looking sources, e.g. Harvard (ref 32), Stanford (ref 33), NPR (ref 38), Columbia (ref 41). 

The authors note that most positive sunscreen content on TikTok is based on cosmetic benefits rather than anti-cancer benefits, which is true in my experience. But the finding that only 6% of highly viewed TikToks explicitly mentioned the cancer-reduction benefits of sunscreen may not necessarily be a missed public health opportunity, in my opinion. Content that increases the uptake of sunscreen for other reasons is still beneficial, and there are advantages to avoiding this topic. 

Mentioning the anti-cancer benefits may reduce content visibility, so this finding may be the result of low audience engagement leading to low viewership. 'Sunscreen prevents cancer' is standard health advice that lacks many elements for virality. Additionally, mentions of some related keywords like 'death' lead to suppression in the TikTok algorithm, and shorter content tends to perform better - the extra time required to mention this benefit may reduce reach. 

Increasing knowledge of health risks has traditionally been the focus of public health campaigns, but it does not necessarily increase the uptake of health behaviours. There is evidence that this is the case for sunscreen - in our BeautySciComm survey, we found that aesthetic properties are a major barrier to frequent use, with ~1/3 of respondents nominating this as a reason (this aligns with other studies. 

Knowledge of sunscreen’s benefits for skin appearance was also a greater driver for sunscreen uptake than anti-cancer benefits in our survey.  

Discussion of cosmetic benefits may be especially useful for counteracting the appearance-based benefits of suntanning, popular with younger audiences who see long-term health risks as irrelevant to them.  

Sunscreen has become an increasingly politicised topic, so 'bypassing' (talking about sunscreen in a generally positive light) may be a valuable tool for increasing health behaviour, whereas mentioning cancer risk may cause defensiveness and thus strengthen misguided beliefs. Content creators may also be aware that discussing anti-cancer benefits may lead to heated comments they are not well-equipped to effectively counter, even if they believe it is a benefit. 

Cancer-prevention benefits are often overstated, particularly by US-based content creators who often emphasise the need for everyone, regardless of skin tone, to wear sunscreen every day. This doesn’t align with the evidence (see e.g. the Australian sun exposure guidelines, which are based on UV index with the latest version stratified by skin tone), and this may lead to further erosion of trust. 

The authors also note that content on sunscreen rarely mentions other forms of sun protection (only mentioned in 7.2% of sunscreen promotion content), and this also aligns with my observations. I would say this is a bigger missed public health opportunity: 

Many anti-sunscreen people are open to wearing 'chemical-free' protective clothing and utilising shade. However, I would caution presenting these methods as alternatives to sunscreen, as this tends to imply the other option is 'unsafe' and unnecessary.  

Other forms of sun protection are less error-prone than sunscreen, which is often applied inadequately, with skipped spots, low application amounts and low reapplication.