Health Influencers on Social Media

Social media have become an important source of health-related information, especially for young people. Everyone can create and share health-related content on social media and some individual users attract large numbers of young followers. Such users are also called influencers because their content has high outreach and can influence the attitudes and behavior of the recipients. The research team is particularly interested in so-called health influencers, influential social media users who post content on health-related topics. These influencers can have a health- promoting effect, for example, when they share evidence-based information and inspire young people for healthy lifestyles. However, they can also have adverse effects on public health when serving commercial interests or sharing misinformation. The project team investigates three key questions in this context: (1) Who are the most prominent health influencers young people engage with? (2) Which health topics are they covering? (3) How does following these health influencers affect adolescents health attitudes and behavior? To identify health influencers, the researchers will initiate a citizen science process with young people. In citizen science, lay citizens perform the roles of professional researchers and engage in different steps of the research process. In this study, school students all over Austria will be invited to engage in a crowdsourcing process. In this process, they screen their digital environments and create a unique database of health influencers, which provides a rich resource for future research. To analyze the content of the identified health influencers, the researchers will conduct a content analysis of their social media accounts and posts. In this content analysis, the health influencers will be characterized on the profile level (e.g., gender, outreach, expertise) and the post level (e.g., topics of the posts, level of evidence, frames). Finally, the research team will implement a longitudinal survey with adolescents to understand the impact of following health influencers on social media. The participants will report which health influencers they are following. The research team will observe how young people who follow certain types of health influencers change their attitudes, knowledge, and behavior over time. Taken together, the project results will provide a holistic perspective on the role of health influencers in young peoples information diets. The researchers will identify key health influencers, open the black box of the content they post and provide first evidence on the impact of following these influencers across time. Based on the results, the research team will derive guidelines to tackle health misinformation and leverage health influencers positive potential in high-choice and personalized media environments.

Health influencers have become an important source of health information for young people. The HISM project ("Health Influencers on Social Media") shows that this brings both opportunities and risks: influencers can communicate health topics in an accessible and relatable way, but health information, personal experience, and commercial interests are often closely intertwined. The project examined what health-related content young people encounter on social media, how they assess it, and what effects it may have. In a citizen science study, 336 adolescents from 16 Austrian schools documented 2,147 posts by 255 influencers on Instagram, TikTok, and YouTube. Around 60% of the posts were rated as beneficial to health and only 4.5% as harmful. At the same time, 41.5% contained advertising. A more detailed analysis showed that problematic aspects were sometimes overlooked, including misleading health claims, unrealistic body ideals, or links between healthy lifestyles and promoted products. A survey of 1,003 adolescents and young adults also showed how present influencers are in everyday information use: around 93% encounter influencer content at least occasionally, and around 83% encounter health-related influencer content. More than one third deliberately follow health influencers. Around 31% had already purchased a health product recommended by an influencer. The close connection between health communication and advertising was particularly evident for dietary supplements. A content analysis of 1,120 product presentations in 727 Instagram posts by 84 influencers found that 97% were advertisements, yet almost three quarters were not disclosed as such. Potential benefits were mentioned in 24% of presentations, while potential harms appeared in only 2.3%. Information on drug interactions, contraindications, or contamination risks was entirely absent. MANUSCRIPT_EE Mental health content presented a more differentiated picture. In an experiment with 499 young people, brief one-time exposure to such posts did not lead to an overall increase in self-labeling, perceived need for professional help, or fears of future mental health problems. Interviews with 19 mental health influencers also showed that they combine personal experience, health information, support, and, in some cases, commercial interests. Overall, HISM shows that health influencers should be viewed neither only as a risk nor as a reliable source of health information. Their reach creates opportunities for accessible health communication, but also makes it important to distinguish critically between advertising, personal experience, and scientifically grounded information. The findings are therefore particularly relevant for young people, schools, parents, and health organizations.