Google’s AI Overviews cite YouTube more frequently than any medical website when answering health-related search queries, according to a German study that analysed more than 50,000 searches.
Researchers at SE Ranking found that YouTube accounted for 4.43% of all sources cited in AI-generated health summaries, making it the single most referenced platform. No hospital network, government health body or academic institution came close. The findings raise concerns because YouTube is a general video platform where content can be uploaded by anyone, not a dedicated medical publisher.
The study, based on German-language searches conducted in Germany, showed AI Overviews appeared in more than 82% of health searches. While some highly cited YouTube videos came from hospitals or licensed professionals, these made up less than 1% of all YouTube links referenced.
Google said its AI Overviews are designed to surface high-quality content regardless of format and argued that many YouTube videos cited come from reputable medical sources. Independent experts, however, said the research suggests the system may prioritise popularity and visibility over medical authority, posing structural risks when people rely on AI summaries for health information.
