The Facts About UC Davis Olive Center's Olive Oil Report

September 20, 2017

Many false stories are circulating around the internet about olive oil fraud citing a report prepared by the University of California Davis Olive Center. These stories often list some well-known olive oil brands and claim that the oils are adulterated. 

In fact, the UC Davis Olive Center report did not find any adulteration or cutting of olive oils with either seed, nut or vegetable oils. Attempts to use the report to spread stories of olive oil fraud are misleading. Read more below.



There have been frequent public claims that a University of California Davis Olive Center report published in 2010 found that 69 percent of imported extra virgin olive oil sold in the U.S. is "fake" (i.e. adulterated with lower-grade oils). This is false and misleading, and here's why.

Taste Tests are Subjective

Chemical Lab Tests are Objective

UCD-OC-Report-Fact-Sheet_img1.pngThe report claimed two-thirds of imported samples labeled as extra virgin olive oil did not meet sensory standards (i.e. taste testing), which is a subjective measure. UCD-OC-Report-Fact-Sheet_img2.pngUsing chemical lab tests – the ONLY accurate way to tell if an oil has been adulterated – the report found NO signs of adulteration based on International Olive Council (IOC) and U.S. Department of Agriculture (USDA) standards.

The Report Had Industry Funding

Scientifically Meaningless Sample Size

UCD-OC-Report-Fact-Sheet_img3.pngThe report was funded by California olive oil producers and companies, which have a financial interest in increasing market share and damaging the reputation of imported oils. The only brands reported to pass every test in the report are brands from organizations that funded the report. UCD-OC-Report-Fact-Sheet_img4.pngThe number of samples was statistically very small (52) and only from California, rendering the results scientifically meaningless. Additionally, samples in the study were not collected by independent agents.

The Results Could Not Be Replicated

UC Davis: It's Frequently Misinterpreted

UCD-OC-Report-Fact-Sheet_img5.pngClass-action attorneys attempted to reproduce the UC Davis results and failed, finding that "replicating the UC Davis tests proved impossible." These attorneys had a strong financial interest to see those test results successfully reproduced, but they still couldn't do it. UCD-OC-Report-Fact-Sheet_img6.png"[The report] partly got misinterpreted because it's easier in the media to report that something's fake. It also plays into the bigger story about inauthenticity in food." - Dan Flynn, executive director of the UC Davis Olive Center, in an interview with The Seattle Times. The article added, "[Flynn] also suspects that many people who wrote about the report didn't actually read it."

More Than 98% of Olive Oil Sold in the U.S. is Authentic

UCD-OC-Report-Fact-Sheet_img7.pngData from the NAOOA's testing of hundreds of olive oils annually in independent IOC labs over 25 years supports the finding that more than 98 percent of olive oil sold in U.S. retail outlets is authentic. Our NAOOA Certified Quality Seal Program is even more robust, requiring products to be submitted for chemical lab testing more frequently and including organoleptic analysis.

Brands that participate in the NAOOA Certified Quality Seal Program agree to have samples taken directly from the retail marketplace, just as any consumer would buy them.

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Posted in: Olive Oil Quality