NATION'S MOST COMPREHENSIVE OLIVE OIL TESTING STUDY FINDS NO ADULTERATION IN TOP 15 BRANDS, PRIVATE LABEL BRANDS

• No adulteration found in 190 samples of olive oil representing top 15 brands (85% of the market) and 37 private label "store brands" from off-the-shelf purchases at U.S. and Canadian retailers.
  
  
• Independent study was designed and overseen by Tassos C. Kyriakides, Ph.D., assistant professor of biostatistics at Yale University.
  
  
• Independent third-party sampling agencies and International Olive Council-recognized laboratories carried out all sample procurement and brand-blind testing.
  
  
• The authentic extra virgin olive oils tested met two key health-related parameters (content of oleic acid and phenolic compounds), even in some cases where overall grade quality may have fallen short.

NEPTUNE, N.J., Sept. 4, 2025 /PRNewswire/ -- The North American Olive Oil Association (NAOOA) is pleased to announce the results of its 2024 Olive Oil Testing Program, which was the largest initiative of its kind ever conducted in the United States. NAOOA retained Tassos C. Kyriakides, Ph.D., assistant professor of biostatistics at the Yale University School of Public Health, to design and oversee the study.

According to the study report issued by Dr. Kyriakides, a representative sampling of 153 olive oils from leading brands (those with more than 1% of national market share) revealed no instances of adulteration (i.e., undisclosed mixing with non-olive oils) when tested against International Olive Council (IOC) standards. Testing of 37 bottles of store brand olive oils confirmed their purity, as well.

"This is great news. The top concern we hear from consumers is whether the olive oil they're buying might be cut with seed oils—a fear largely driven by sensational claims on social media about so-called 'fake' olive oil," said NAOOA Executive Director Joseph R. Profaci. "But I can't say I'm surprised. These results are consistent with NAOOA's internal testing over the past decades, including testing we supervise for our NAOOA Certified seal program."

Dr. Kyriakides' sampling protocol also included the random selection and testing of an additional 26 products—brands representing less than 1% market share from the bottom 15% of the market. The group included 21 extra virgin olive oils (EVOO) and 5 regular olive oils (OO). Among these lesser-known brands, one EVOO and one OO sample were found to be adulterated. According to the report, these products held market shares of just 0.15% and 0.36% respectively. The adulterated EVOO sold for more than 50% below the average retail price of the other EVOO samples—highlighting that an unusually low price could be a red flag to consumers.

Dr. Kyriakides' report concludes that the finding of less than 1% of adulteration aligns with two other smaller, off-the-shelf studies. A report from the UC Davis Olive Center in 2010-11 found no economic adulteration, and a peer-reviewed study published by U.S. Food and Drug Administration (FDA) scientists in 2015 found no confirmed economic adulteration and concluded the risk of such adulteration of EVOOs was "low." 

"While NAOOA is pleased with the reported results, we as an industry cannot abide any incidence of economic adulteration," said Mouna Aissaoui, CEO of Pompeian and NAOOA board chair. "The NAOOA board plans to pursue legal action against the bad actors we have identified through this testing program." 

The 2024 testing program was launched as part of NAOOA's mission to promote quality and ensure American consumers have access to authentic olive oils. In late 2023, media reports raised concerns that a sharp rise in olive oil prices, driven by two consecutive bad harvests, might lead to a surge in adulterated products on U.S. supermarket shelves.

Olive oil testing generally falls into two categories: "purity," which checks for adulteration with extraneous oils (like the results referenced above), and "quality," which assesses whether the product meets the quality parameters for each grade. Since the drought and high temperatures that impacted production could also negatively impact the quality of the oils, NAOOA asked Dr. Kyriakides to assess the tested EVOOs both for grade quality (whether the product was consistent with the extra virgin grade) and other parameters of oil composition linked to the health attributes of EVOO (oleic acid and phenolic compounds).

Dr. Kyriakides explains in his report that assessing grade quality of an olive oil on the shelf is difficult because, unlike with purity, quality parameters can be negatively impacted by exposure to heat and light and the passage of time. Despite the rigor of the study, the report explains that it did not control for those factors — either before the products tested were placed on the shelf or after they were purchased but prior to testing, which in this case involved unforeseen delays in sample collection, shipping and testing.  Because of this, although the testing revealed some questionable results (e.g., the report notes that 18 of the EVOO samples (11%) that were tested failed more than one IOC grade quality parameter), Dr. Kyriakides found that the data do not support definitive conclusions about how the challenging harvest conditions may have impacted grade quality or quality conditions in general.

Regarding the analysis of oil composition linked to the health attributes of EVOO, however, the report finds that, on average, a subset of the EVOOs tested contained levels of oleic acid and polyphenols that exceeded the thresholds required for making qualified health claims as established by the FDA and the European Food Safety Authority (EFSA), respectively. Indeed, the report finds that the 18 samples that it noted failed more than one IOC quality parameter all exceeded the polyphenol health claim threshold, averaging 283 mg/Kg, and had an average 67.9% MUFA content, which also exceeds the monounsaturated health claim requirements. It is important to highlight that these two parameters are not a comprehensive study of all components in EVOO associated with its health benefits.

Upon reviewing the study's findings, NAOOA has committed to taking the following action:

• Legal: NAOOA will take legal action against the brands with confirmed adulteration, as well as any bad actors identified in a separate sampling of 37 olive oil products collected at wholesale and referenced in footnote 2 of the report.
  
  
• Further Analysis: NAOOA's Quality Control Committee intends to gather additional information to better understand if the grade quality results were negatively impacted by supply chain issues and assess the reliability of 'best-if-used-by' dates.
  
  
• Further Testing: NAOOA's board will be asking members to support its plans to allocate additional funding for testing in 2026, including expanding the scope of the organization's testing program to include restaurants, foodservice providers and product manufacturers to assess authenticity and quality beyond the retail shelf.
  
  
• Retailer/Distributor Education: Retailers and distributors play a crucial role in helping preserve olive oil quality once it leaves the manufacturer. NAOOA and its member companies will ramp up efforts to provide best-practice guidance for the supply chain including transport, storage and even display conditions.

NAOOA is the largest olive oil trade association in the United States, with over 65 members representing the full spectrum of the sector—from artisan producers to large multinational companies. Collectively, NAOOA members represent about two-thirds of all olive oil sold in the U.S. Recognizing the importance of the 2024 testing program, three non-member companies representing the brands California Olive Ranch, Lucini, Graza and Cobram Estate also agreed to participate and share in the program's costs. Together, these companies and NAOOA's members represent all but one of the top 15 U.S. EVOO brands.

Contact: [email protected]

SOURCE North American Olive Oil Association