Peanut Oil and Allergy: When Is It Safe to Eat, When Is It Not?

in Food Allergy, Peanut & Tree Nut
Published: November 22, 2022
Bottle of peanut oil. Peanut oil allergy.
Photo: Getty

Does experiencing an allergic reaction after consuming food containing peanut oil indicate a person has a peanut oil allergy? The allergy would be to peanut protein, not specifically to the oil. 

But the question remains whether those with a peanut allergy need to worry or not about eating foods cooked in or containing peanut oil. Peanut oil is included as an ingredient in some processed foods, and is used at some restaurants for frying, sautéing or adding flavor.

So, figuring out whether to avoid it all together or to eat certain types of peanut oil can be tricky. In this article, we’ll explore the nuances of peanut oil allergy vs. tolerance with experts.

Uncertainty over the safety of peanut oil affects millions of Americans with a peanut allergy. Two prevalence studies conducted by a team at Northwestern University found that about 4.5 million adults and 1.6 million children in the United States have a peanut allergy. The study found peanut allergy to be the most prevalent food allergy among children.

Symptoms of a Peanut Allergy Reaction   

A food allergy occurs when a person’s immune system identifies proteins in a food as harmful, which triggers a defensive response. The immune system begins to produce antibodies – called IgE – against that food, such as peanut. These antibodies attach to mast cells. When the person again consumes peanut, the proteins from it become attached to the IgE antibodies. This causes the mast cells to release histamine and other chemicals. These cause the symptoms of allergy. 

Symptoms of a peanut allergy may include any of the following: 

  • Tingling in the mouth
  • Swelling of the tongue and throat
  • Hives, itchy skin or skin redness
  • Breathing difficulty, wheezing
  • Abdominal cramps
  • Vomiting
  • Faintness, due to a sudden drop in blood pressure
  • In a severe anaphylactic reaction, the allergic person can lose consciousness and is at risk of death.  

If you experience symptoms of an allergic reaction after eating food that contains peanut or was cooked in peanut oil, it is important to see an allergist. He or she will consider your symptoms and likely conduct allergy tests. If diagnosed with a peanut allergy, it is vital to carry epinephrine auto-injectors. 

Peanut Oil Allergy: Type of Oil Matters

The way peanut oil is processed dictates the amount of peanut protein in the oil.

Highly refined oil: This type of peanut oil undergoes processing that separates the protein from the fat. Peanut protein – not fat or oil – is what triggers an allergic reaction, says Dr. Scott Sicherer, director of the Jaffe Food Allergy Institute at Mount Sinai in New York. 

“Highly refined peanut oil should be tolerated by most people with peanut allergy,” says the allergist.

Unrefined or crude oil: This form of peanut oil is made by squeezing the peanuts to extract the oil. It’s important to know that peanut protein still exists in this product. Unrefined oil, also called “gourmet,” “cold-pressed,” “extruded,” “aromatic,” or “small-batch” may be used as a finishing oil in cooking. 

“Consuming unrefined peanut oil is essentially like eating peanut. It can cause a reaction,” Sicherer says. 

There has been some research into the safety of peanut oil based on the processing it undergoes. One study in 1997 examined whether highly refined peanut oil versus its unrefined version would trigger allergic reactions. It found that none of the 60 participants (all with a peanut allergy) reacted to the highly refined peanut oil. However, six participants did react to the crude oil.

Consumers can find several varieties of peanut oil at grocery stores or online retailers. So, it is essential to pay attention to the way the oil is processed to determine whether it is safe when a family member has peanut allergy.

Labeling and Peanut Oil Allergy Rules

Government food safety regulators have also weighed in on peanut oil and allergy.

The FDA does not require a product that contains highly refined peanut oil to be listed under the Food Allergen Labeling and Consumer Protection Act (FALCPA). FALCPA requires the top 8 major allergens (peanuts, tree nuts, wheat, milk, egg, soy, fish and shellfish) to be clearly labeled on packaged foods. (In 2021, the FASTER Act added sesame as the ninth top allergen.) 

FALCPA exempts highly refined oil from the labeling law because the processing removes the protein. 

However, dietitian Dr. Carina Venter points out that manufacturing companies might not know whether they are using highly refined peanut oil. An associate professor at the University of Colorado’s school of medicine, Venter also notes that Europe takes a different approach. 

The European Food Safety Authority (EFSA) does not conclude that highly refined peanut oil is necessarily safe for peanut allergy. A scientific panel reported to the EFSA that more investigation of the risk for peanut oil allergy was needed. Venter says a concern was the limitation of some testing equipment in detecting peanut protein in oils.

Canada’s health regulator, meantime, continues to require labeling for refined peanut oil. 

Sicherer recommends speaking to your doctor about your concerns and discussing whether it would be safe for you to consume even the highly refined peanut oil. It is important to seek your doctor’s advice specific to your medical history.

Dining Out with Peanut Oil

Chef cooking in a kitchen with peanut oil. Peanut oil allergy.
Photo: Getty

Communication is key when trying to avoid an allergic reaction from peanut oil whether dining in (reading labels and cooking at home) or dining out.

If a product lists peanut oil among its ingredients, call the manufacturer to find out whether it is highly refined. When they don’t know or can’t guarantee that it is, then pass on it. 

“If you know it’s highly refined, it should be safe. When you don’t know or it is not highly refined, then it’s best to avoid,” Sicherer says.

The same goes for dining at a restaurant with a peanut allergy. It is essential to ask whether peanut oil is being used and, if so, to ensure that it is highly refined peanut oil. However, restaurant staff can’t always tell you specifically what type of oil they are using. 

Peanut oil is a popular choice for frying foods because of its high smoke point. It also does not absorb the flavors from the foods that are fried in it, making it a favored choice when frying multiple types of foods in the same oil. Peanut oil is also a popular choice in some Asian cooking, especially to add flavor as a finishing oil. 

Food allergy advocate and cookbook author Sharon Wong has a few tips that have helped keep her family safe when dining out. She reads restaurant review sites, specifically searching for key words like “allergy,” “peanut” or “anaphylaxis” to see what other diners have said about those topics. That helps her weed out dining spots that have not proven they can accommodate food allergies. 

Peanut Oil and Asian Cuisine

Wong, who founded Nut Free Wok, a blog about allergy-aware Asian fare, has asked several Asian restaurants in California’s San Francisco Bay Area where she lives if they use peanut oil. They have told her that they opt for vegetable or cottonseed oils instead because they are cheaper. However, in other locations, such as the San Diego area, she has encountered more Asian restaurants that use peanut oil.

An important fact when dining: it’s not safe to assume similar types of restaurants would be using the same types of oils. 

In general, Wong’s family tries to avoid restaurants that do a lot of deep-frying. Instead, they choose restaurants featuring foods that are steamed or stir-fried with other oils. When dining at Chinese, Korean or Vietnamese restaurants, Wong brings an allergy dining card translated into the language of the restaurant staff. This adds another layer of important communication.

Regardless of the type of restaurant cuisine, it is not enough to ask whether a restaurant uses peanut oil and whether it is unrefined, Wong says. It is important to go a step further to ensure that peanuts or nuts are not being fried in the oil, resulting in cross-contamination.

Substituting Peanut Oil

Wong’s family avoids peanut oil in all forms. Her family made the decision when her peanut-allergic son was younger, since he was highly sensitive.

In her kitchen, Wong usually cooks with sesame or olive oil. Other substitutes she has used are: grapeseed, avocado, sunflower and canola oils.  

Whether you choose to completely avoid peanut oil or consume only the highly refined version, with an allergy it is important to be vigilant. When eating foods fried in or containing any type of oil, ask questions to ensure it is safe for you.

If you think you have had an allergic reaction to peanut oil, a doctor can help determine whether you are allergic to peanuts and advise you on how to proceed.

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Prevalence of Common Food Allergies in Kids
Baked Food Challenges for Milk Allergy, Egg Allergy