Google’s AI Overviews cite YouTube more than any medical website when answering health-related search queries, according to a German study that analysed more than 50,000 searches. Researchers found YouTube accounted for 4.43% of all citations in AI-generated health summaries—more than hospitals, government health portals or academic institutions—raising concerns about the reliability of information shown to an estimated 2 billion users each month.
The study, conducted by SEO platform SE Ranking using German-language searches, showed AI Overviews appeared in over 82% of health queries. While some highly cited YouTube videos came from hospitals or licensed professionals, researchers warned these represented less than 1% of all YouTube links used, meaning much of the content could come from non-experts.
Google said its system surfaces high-quality information regardless of format and that many credible health authorities publish on YouTube. However, independent experts said the findings suggest structural risks, with popularity and visibility outweighing medical authority in how AI Overviews source health information.
