Google’s AI Overviews, which appear at the top of search results and are seen by about 2 billion people a month, cite YouTube more often than any medical website when answering health-related questions, according to a new German study.
Researchers at SE Ranking analysed more than 50,000 health queries made in Germany and found YouTube accounted for 4.43% of all sources cited by AI Overviews – more than hospitals, medical associations or public health bodies. By comparison, established medical references and health portals each made up around 2% or less.
The findings raise concerns because YouTube is not a medical publisher and hosts content from both qualified professionals and untrained influencers. Critics say this suggests AI Overviews may prioritise popularity and visibility over medical authority.
Google said its system is designed to surface high-quality information across formats and that many cited YouTube videos come from hospitals and licensed professionals. However, researchers noted that these reputable videos represented less than 1% of all YouTube links cited.
Independent experts said the study suggests risks in AI-generated health information are structural, not isolated. Google has previously said AI Overviews are reliable and cite trusted sources such as the Centers for Disease Control and Prevention and the Mayo Clinic, but the research indicates non-medical platforms still dominate citations.
