I’m allergic to peanuts, tree nuts, and shellfish. I’ve learned firsthand that sometimes allergens show up in places you’d least expect. Like the time I found peanuts on a chair in the airport. Or when I ate at a restaurant that used peanut butter as a thickener in their pizza sauce!
To further complicate things, peanut oil is commonly used as a cooking oil in commercial kitchens. Chains like Chick-Fil-A use peanut oil because of its high smoke point—they also claim it to be a critical ingredient in their signature fried chicken. Many servers don’t know what type of oil their kitchen uses, and may incorrectly assume it’s safe for a food-allergic patron.
You may have heard highly-refined oils like peanut oil and soybean oil don’t cause allergic reactions. In today’s blog, we break down the truth of this statement, and share our tips for finding out what oil is in your food!
What type of oil are you eating?
When you’re at a restaurant, it’s generally a good starting point to ask what type of oil the kitchen uses, and confirm they have procedures in place to prevent cross-contact. I usually ask this before perusing the menu. Very often the answer is: vegetable oil. If you have a peanut allergy, this may sound safe enough. However, while vegetable oil most often means canola, corn, or soy-based oil, in some rare cases peanut oil may be in the mix. This is because peanuts are not actually nuts—they’re legumes!
So, if a restaurant tells you they use vegetable oil in their kitchen, it’s worth asking them to check the ingredient label. The label should contain additional details that identify whether peanut or soy are in the vegetable mix, as the law requires that all oils are listed out individually on food labels.
Is your oil refined or unrefined?
Navigating oils goes a bit deeper, as they generally fall under one of two subcategories:
Highly-refined/refined: These oils are most common in commercial kitchens and are typically used for cooking or frying. Because this type of oil undergoes heavy processing, refined oils are broadly considered not to contain significant quantities of the allergenic food proteins that trigger allergic reactions.
Unrefined/crude: These oils undergo minimal processing. Unrefined oils are generally used as a finishing oil and are known for their potent flavor and smell. Another way to identify whether the oil is unrefined or crude is to look for labels like “gourmet,” “cold-pressed,” “extruded,” “small-batch,” or “aromatic.” These oils generally contain very small quantities of allergenic food proteins.
It’s unusual to find unrefined oils outside of fine dining environments (you likely won’t find these oils at fast-casual chains), but remember, it’s always better to ask! And if you’re not 100% sure, err on the safe side and assume the oil is crude or unrefined. In my opinion, this one falls very squarely in the “better safe than sorry” category. 😉
What do the regulators say?
Notably, highly-refined oils like soybean oil or peanut oil are considered non-allergenic by the FDA. This means that if a food contains peanut or soybean oil, you will see it in the ingredients list, but you won’t see it in an allergen statement on the packaging.
According to the FDA, “raw agricultural commodities (generally fresh fruits and vegetables) are exempt [from labeling requirements] as are highly-refined oils derived from one of the eight major food allergens and any ingredient derived from such highly-refined oil.”
You can learn more about food allergy labeling laws in our previous post!
What do the scientists say?
On the upside, research has shown refined peanut oil can be safely consumed by the vast majority of individuals with peanut allergies. Unrefined oil, conversely, has shown to cause reactions in some cases.
The most relevant study of note was conducted in 1997. In this study, 60 individuals with severe peanut allergies consumed both highly refined and unrefined peanut oil. Of those that consumed refined oil, zero participants had an allergic reaction; of those that ingested unrefined oil, six showed symptoms.
Still, some reports claim refined oils were the cause of allergic reactions, likely due to defects in the manufacturing process. Two studies, in 2000 and 2017, were conducted to refute these claims and quantify the risk of allergic reactions to highly-refined oils. These researchers confirmed the findings of the 1997 study with one reporting, “peanut oil, and by extrapolation other edible vegetable oils, presents no risk of provoking allergic reactions in the overwhelming majority of susceptible people.”
At Allergy Amulet, we’ve done some testing of our own on highly-refined oils (e.g., vegetable, peanut, soybean, canola, etc.) and so far, we have not detected trace allergenic material in our samples. Our Allergy Amulet assays are designed to detect the allergenic ingredient if the allergen in the oil is present at levels high enough to trigger a reaction in the most sensitive food-allergic individuals.
All in all, the general consensus in the allergy research community is that highly-refined oils, like soybean and peanut, are safe for the overwhelming majority of people managing food allergies. However, in many cases, doctors and allergists will still recommend individuals with allergies, especially those of a young age, avoid oils derived from their allergen. So, before you go enjoy a Chick-Fil-A sandwich, we recommend you first consult with your allergist or provider.
— Scott and the Allergy Amulet Team
This piece was reviewed by the Allergy Amulet science team and advisor Dr. Bert Popping.
Dr. Popping is the managing director of FOCOS, a Germany-based food consulting firm. He has more than two decades of professional experience in the food industry, and has authored more than 50 publications on topics covering food authenticity, analysis, and validation. He is a member of the editorial board of J.AOAC, J. Food Additives and Contaminants, and J. Food Analytical Methods and Quality Assurance and Safety of Crops & Foods, and serves on advisory committees for AOAC International and the European Commission under the Horizon 2020 (H2020) program. Dr. Popping is an active member of numerous national and international organizations including CEN, ISO, and BSI.