Study Finds No Widespread Adulteration In Top Olive Oil Brands
A study of 190 olive oils sold under national brands and retail private labels found no instances of adulteration when tested against International Olive Council (IOC) standards, according to the North American Olive Oil Association (NAOOA).
The research was completed for the NAOOA by Tassos C. Kyriakides, Ph.D., assistant professor of biostatistics at the Yale University School of Public Health, and sampled 37 store brand olive oils and 153 olive oils sold under national brands. Adulteration occurs when a product supplier mixes olive oil with non-olive oils.
The report did not identify any of the private label brands or national brands that were tested.
“This is great news,” said Joseph R. Profaci, executive director of NAOOA. “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. These results are consistent with NAOOA’s internal testing over the past decades, including testing we supervise for our NAOOA Certified seal program.”
The report from Kyriakides concluded 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."
NAOOA said the 2024 testing program was launched as part of its 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.
The sampling protocol used by Kyriakides also included the random selection and testing of an additional 26 products, representing less than 1% market share from the bottom 15% of the market. The group included 21 extra virgin olive oils (EVOO) and five 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 for consumers.
“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.”
Upon reviewing the study's findings, NAOOA said it has committed to taking the following actions:
- 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, food-service 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.
