Google AI Overviews cite YouTube more than medical sites for health advice, study reveals

Google's AI health summaries cite YouTube more than any medical source, study finds

Serving tech enthusiasts for over 25 years. TechSpot means tech analysis and advice you can trust. WTF?! When users type a health-related question into Google, the top result now often comes from an AI-generated summary rather than a traditional blue link. However, new research reveals that the source behind these AI explanations is not a medical authority - it's YouTube. A large-scale analysis by SE Ranking, a search engine optimization platform, examined 50,807 health-related searches conducted in Berlin on Google. The study found that Google's AI Overviews, which automatically summarize search results using generative AI, cited YouTube more than any other source. The video platform appeared in 4.43 percent of all citations, surpassing any hospital network, health ministry, or academic medical site. YouTube, the world's second-most-visited website, thus emerges as the single most influential source shaping how AI Overviews explain health conditions, a striking finding for a company that insists the tool "surfaces high-quality content from reputable sources." To state the obvious: YouTube is not a medical publisher. On a platform where anyone - from licensed physicians to lifestyle vloggers - can upload content, authority can vary widely. While YouTube topped the list with over 20,000 citations across roughly 466,000 total source mentions, the next most-cited domains lagged far behind. Germany's public broadcaster, NDR.de, ranked second with just over three percent, followed by medical reference site Msdmanuals.com (2.08 percent), health portal Netdoktor.de (1.61 percent), and doctors' career site Praktischarzt.de (1.53 percent). Overall, AI Overviews appeared in more than 82 percent of the health searches analyzed. The study used only German-language prompts, reflecting search patterns in a country with tightly regulated medical information governed by both German and EU standards. SE Ranking's authors noted that if generative AI systems skew toward non-medical sources even in such a regulated environment, similar patterns may be inevitable elsewhere. In response to the findings, Google told The Guardian that AI Overviews draw on credible information "regardless of format," noting that many medical professionals and hospital channels publish content on YouTube. The company emphasized that the results of a single German-language study cannot be generalized globally. Google also cited the same dataset to argue that its system largely relies on expert content: of the 25 most-cited YouTube videos, 96 percent came from verified medical channels. However, those 25 videos accounted for less than one percent of the total YouTube citations examined, researchers noted - a fraction too small to represent the broader sample. Concerns about AI Overviews go beyond citation patterns. Earlier this month, a Guardian investigation documented examples of misleading and even dangerous medical summaries generated by the system, including false information about liver function tests. In response, Google temporarily suspended AI Overviews for some - but not all - medical searches. Academic observers say the SE Ranking data underscores the structural nature of these risks. "This study provides empirical evidence that the risks posed by AI Overviews for health are structural, not anecdotal," said Hannah van Kolfschooten, a researcher at the University of Basel studying the intersection of AI, law, and health. "The heavy reliance on YouTube rather than public health authorities suggests that visibility and popularity, rather than medical reliability, drive the system." The study's snapshot approach - taken in December 2025 - means the results could shift over time or vary across regions. For now, the data show that Google's AI tool, designed to simplify complex questions, still relies primarily on sources shaped by engagement and popularity.

If you use Google AI for symptoms, know it cites YouTube a lot

In a December 2025 snapshot, YouTube made up 4.43% of AI Overview citations, far ahead of major medical reference sites, so your quick answer may start with video content. Google's AI Overviews are starting to look like a shortcut for symptom questions, but the sources behind those summaries may surprise you. In a December 2025 snapshot of 50,807 German-language health searches, YouTube was the most-cited domain inside AI Overviews. Google AI health advice can feel definitive even when it's built on a mix of links that don't share the same medical standards, but if you're using the overview for reassurance, treat the citations as the real product, not the paragraph at the top. YouTube is the top citation In the analysis, YouTube made up 4.43% of all sources cited inside AI Overviews, or 20,621 links out of 465,823 total. No other domain showed up more often. Recommended Videos The gap is what should change your behavior. YouTube was cited about 3.5 times more than NetDoktor and more than twice as often as MSD Manuals, both established health information publishers. So even when traditional references are available, the AI response can still steer you toward video first. The AI digs past page one The overview box also doesn't mirror normal search rankings. Only 36% of AI-cited links appeared in Google's top 10 organic results for the same prompts, and 54% appeared in the top 20. That's a big shift in what gets visibility. In this snapshot, YouTube ranked 11th in organic results when you strip out search features and look only at standard links, yet it rose to the top inside AI Overviews. The AI can pull in material you likely wouldn't have clicked through from the usual results page. A safer way to use it The study grouped sources by reliability signals and found 34.45% landed in a "more reliable" bucket, while 65.55% came from sources without strong evidence-based safeguards. Government and academic sources were roughly 1% combined. Use Google AI health advice as a starting point, then jump to higher-bar medical references fast. Click through, look for clear editorial oversight and medical review, and don't let a confident summary outweigh professional care. This was one limited study in Germany, and results may vary by region and rollout.

Where does Google's AI get its health advice? A study points to YouTube

Every month, around two billion people see AI Overviews, Google's AI-powered search feature that generates summaries to users' queries. Now, a new study is revealing a concerning pattern among some of these responses: When asked health-related questions, AI Overviews appears to turn to YouTube significantly more often than trusted medical sites. Since its inception, AI Overviews has faced its fair share of controversies, from early reports of the product spewing nonsensical answers to a series of lawsuits from businesses and publisher groups alleging that the feature is damaging to organic traffic patterns. The most recent concern with AI Overviews emerged via an investigation from The Guardian on January 2, which alleged that the tool has a tendency to provide users with false, misleading, and potentially dangerous health guidance. At the time, Google refuted those claims. Now, a new study from the AI SEO tool SE Ranking, published on January 14, has revealed that AI Overviews is two to three times more likely to cite YouTube videos than "trusted medical sites" in response to health queries -- but Google says that's not the full picture. "From the AI's point of view, all of this content exists in the same pool." To understand how AI Overviews collects its health guidance on the web, researchers at SE Ranking analyzed more than 50,000 health-related Google searches from German users. That location was chosen, per the study's authors, for its strictly regulated healthcare system.