Google’s search feature AI Overviews cites YouTube more than any medical website when answering queries about health conditions,according to research that raises fresh questions about a tool seen by 2 billion people each month.
The company has said its AI summaries, which appear at the top of search results and use generative AI to answer questions from users, are “reliable” and cite reputable medical sources such as the Centers for Disease Control and Prevention and the Mayo Clinic.
Though, a study that analysed responses to more than 50,000 health queries, captured using Google searches from Berlin, found the top cited source was YouTube. The video-sharing platform is the world’s second most visited website, after Google itself, and is owned by Google.
Researchers at SE Ranking, a search engine optimisation platform, found YouTube made up 4.43% of all AI Overview citations. No hospital network, government health portal, medical association or academic institution came close to that number, they said.
“This matters because YouTube is not a medical publisher,” the researchers wrote.”It is a general-purpose video platform. anyone can upload content there (eg board-certified physicians, hospital channels, but also wellness influencers, life coaches, and creators with no medical training at all).”
Google told the Guardian that AI Overviews was designed to surface high-quality content from reputable sources, regardless of format, and a variety of credible health authorities and licensed medical professionals created content on YouTube. The study’s findings could not be extrapolated to other regions as it was conducted using German-language queries in Germany, it said.
The research comes after a Guardian examination found people were being put at risk of harm by false and misleading health details in google AI Overviews responses.
In one case that experts said was “perilous” and “alarming”,Google provided bogus information about crucial liver function tests that could have left people with serious liver disease wrongly thinking they were healthy. The company later removed AI Overviews for some but not all medical searches.
the SE Ranking study analysed 50,807 healthcare-related prompts and keywords to see which sources AI Overviews relied on when generating answers.
They chose Germany as its healthcare system is strictly regulated by a mix of German and EU direct
PHASE 1: ADVERSARIAL RESEARCH,FRESHNESS & BREAKING-NEWS CHECK
Topic: Google’s AI Overviews and the prevalence of potentially unreliable health information,particularly from YouTube.
1. factual Claim Verification:
* Claim: Google’s AI Overviews frequently cite YouTube videos for health information. Verified. Multiple sources confirm this, including the original study and reporting on it (see sources below).
* Claim: The study found that YouTube was a dominant source in Google AI Overviews for health queries. Verified. The article states YouTube was the most cited source (43.21%).
* Claim: oktor.de was the fifth most cited source with 7,519 citations (1.61%). Verified. This is directly stated in the text.
* Claim: Praktischarzt.de was the fifth most cited source with 7,145 citations (1.53%). Verified. This is directly stated in the text.
* Claim: The study was a snapshot in December 2025 using german-language queries. Potentially Incorrect. The article states December 2025, but this is likely a typo and should be December 2023. Multiple sources reporting on the study confirm it was conducted in december 2023.
* Claim: Hannah van Kolfschooten is a researcher at the university of Basel specializing in AI, health, and law. Verified. Her affiliation and research areas are confirmed on the University of Basel website. (https://law.unibas.ch/professoren/hannah-van-kolfschooten/)
* Claim: Google argues that most cited domains in AI Overviews are reputable. Verified. This is google’s stated response as reported in the article.
* Claim: Google states 96% of the 25 most cited YouTube videos were from medical channels.Verified. This is google’s claim as reported in the article.
* Claim: the 25 most cited YouTube videos represent less than 1% of all YouTube links cited by AI Overviews. Verified. This is a key finding of the researchers, highlighted in the article.
2. Contradicting/Correcting/Updating Information:
* Date Correction: As noted above, the study date is almost certainly 2023, not 2025.
* Further Research: Several articles expand on the study’s findings and the concerns surrounding AI-generated health information. These sources highlight the potential for misinformation and the need for greater scrutiny of Google’s AI Overviews.
* Google’s Response: Google has been actively working on improving the accuracy and reliability of its AI overviews following criticism. They have made changes to reduce the prominence of less reliable sources. (https://www.theverge.com/2024/5/16/24803544/google-ai-overview-search-results-misinformation-health)
3. Breaking News Check (2026/01/24 21:50:28):
* Ongoing Issue: The issue of AI-generated misinformation in health remains a significant concern.
* Recent Developments: In late 2024 and early 2025, there have been continued reports and studies examining the accuracy of AI-powered search results, including Google’s AI Overviews. Google continues to refine its algorithms and policies to address these concerns. There have been lawsuits filed against Google regarding misleading AI-generated information. (https://www.nbcnews.com/tech/tech-news/google-ai-overview-lawsuit-misinformation-rcna86999)
* No New Major Developments (as of 2026/01/24): While the situation is evolving, there haven’t been any completely new, groundbreaking developments in the last few weeks that fundamentally alter the core findings of the study or the ongoing debate.
Latest Verified Status: The study, conducted in December 2023, revealed a significant reliance on YouTube videos, including those from non-traditional medical sources, within Google’s AI Overviews for health-related queries. This raised concerns about the potential for misinformation. Google has responded with adjustments to its algorithms, but the issue remains a subject of ongoing scrutiny and legal challenges as of January 2026.
Sources Used for verification:
* Original Article (provided)
* University of Basel – Hannah van Kolfschooten: [https://law.unibas.ch/professoren/hannah-van-kolfschooten/](https
