An allergic reaction is caused by a dysfunction in the immune system. Individuals may experience allergic reactions to foods, insect stings, latex, and other commonly found materials. With food allergies, a naturally occurring protein in a food item is considered an invader by the immune system, so the body fights to remove it, causing inflammation. About 4% of adults and 4% of children 18 years of age or under have food allergies, with a slightly higher percentage in children under 5 years old. As indicated by the reduced incidence in adults, some of these allergies may, fortunately, be outgrown over time.
The Centers for Disease Control and Prevention (CDC) reports that children with food allergies are more likely to have asthma or other allergic conditions. Nearly 90% of food allergies are caused by these common foods: tree nuts (almonds, walnuts, pecans, cashews, pistachios, etc.), peanuts, milk, eggs, fish, crustacean shellfish, wheat, and soy.
Most allergic reactions are not life-threatening, but some can lead to a more severe reaction known as “anaphylaxis,” in which blood pressure drops abruptly and airways and throat swell, which leads to breathing difficulties. When this is not controlled, unconsciousness and death can occur, so it is important to know how to manage severe allergies.
With increasing news coverage on peanut allergy in the past few years, there may be a misperception that there is a high incidence of peanut allergy in the U.S. and worldwide. However, the numbers show that only 0.6 – 1.0% of people have a mild to more severe peanut allergy, and studies show that about 20% of peanut allergies can be outgrown. By comparison, about four times as many adults are allergic to seafood. As with all allergies, those with a family history of allergy, asthma, or eczema, may be at increased risk.
The National Institute of Allergy and Infectious Disease (NIAID) has reported that approximately 1 in 90 people in the United States, or 1.1%, have a tree nut and/or peanut allergy; the Food Allergy and Anaphylaxis Network (FAAN) has stated that it is about 0.6% each. People who are allergic to peanuts are also often allergic to one or more tree nuts (almonds, walnuts, pecans, cashews, pistachios, etc.).
Peanut Allergy Levels
In those who are severely allergic, reactions to peanuts can occur from ingesting just a trace amount. This can cause anxiety, especially for the parents of peanut-allergic children. However, touching, smelling, or inhaling airborne particles from peanuts does not often cause a severe reaction (Simonte SJ, et al. Relevance of casual contact with peanut butter in children with peanut allergy. J Allergy Clin Immunol. 2003 Jul:112 (1): 180-2.)
Smelling the aroma of peanuts is not the same as inhaling peanut particles that could potentially contain the allergenic protein. The aroma of peanuts comes from different compounds that cannot cause an allergic reaction. Also, many people who are allergic to peanuts do not have an allergy to peanut oil, since highly refined peanut oils have very low peanut allergen levels.
In one controlled study, 30 children with significant peanut allergy were exposed to peanut butter, which was either pressed on the skin for one minute, or the aroma was inhaled. Reddening or flaring of the skin occurred in about one-third of the children, but none of the children in the study experienced a reaction either in their lungs or throughout their bodies!
To prevent an allergic reaction, the best recommendation is to avoid intake. To minimize the risk of being exposed to allergens, which may occur by accident, use these guidelines:
- Read labels which highlight allergens on the ingredient list.
- Plan ahead when dining out or attending a party. Call ahead to notify friends, talk with restaurant staff, or use a “chef card,” which lists ingredients to avoid and can be found at the Food Allergy Anaphylaxis Network (FAAN) website at www.foodallergy.org/downloads.html.
- Practice proper sanitation with common cleaning agents, such as hot, soapy water to remove cross-contamination.
- Carry medicine such as epinephrine injector pens, which are also referred to as EpiPensÒ. They must be used within 10 minutes but can provide the time necessary to seek medical attention. Epinephrine is a hormone that is released during stress. It boosts the supply of oxygen and glucose to the brain and muscles, while suppressing other non-emergency bodily processes, such as digestion. Make sure to fill your prescription as one study showed that almost 50% of allergic children did not carry prescribed medication!
- Control asthma with proper medical care, since asthma is a main risk factor for death due to anaphylaxis.
- Let people know about your allergy by wearing a bracelet or necklace identifying the allergy and its severity.
Evidence does not support the effectiveness of allergen bans. In fact, many experts feel that bans, except in situations that involve very young children such as in daycare centers, give a false sense of security. Peanut bans, for example, ignore other potentially serious food allergies. School-aged children need to be prepared to understand real-world environments. Education of faculty, school foodservice personnel, parents and students on how to manage food allergies is thought to be the most effective approach.
The allergens in peanuts have been identified as proteins called Ara h 1, Ara h 2, and Ara h 3. A number of therapeutic interventions to reduce or eliminate peanut allergy are currently being investigated. Among these are Chinese herbal medicine, anti-IgE therapy, oral immunotherapy, and vaccine strategies that utilize genes from peanut proteins.
“Food Allergy Herbal Formula-2” is a Chinese herbal therapy that is being tested and shows promise. When this formula was used in mice for seven weeks it prevented anaphylactic reactions for six months following the treatment. The formula is currently being tested at FDA as a new botanical drug in patients with food and peanut allergy.
Another therapy that has shown some success in increasing the threshold of sensitivity to peanut allergens is called anti-IgE therapy. Immunoglobulin E (IgE) is a type of protein found in our immune system that identifies foreign objects, such as bacteria. This protein is also involved in anaphylaxis that can occur in some who are allergic to peanuts. Injecting other proteins that bind IgE in our blood, helps calm the immune reaction.
Recently, it was shown that the blocking of the certain hormones involved in causing anaphylaxis resulted in significant reductions in the severity of peanut-induced anaphylaxis in mice. In all but one mouse, the reactions were mild.
The most promising emerging strategy is called oral immunotherapy. It uses peanut protein to increase tolerance to peanuts. A 2009 study gave small daily doses of peanut flour, which contains high levels of peanut protein, to peanut allergic children over a number of weeks. All of the allergic children were ‘desensitized’ to the peanut allergen, including one that was highly allergic. The levels of peanut protein were increased two times each week and ultimately the children could eat up to 10 peanuts without a reaction — more than someone would encounter during accidental ingestion.
Although oral immunotherapy remains experimental, it could be extremely valuable to children with severe peanut allergy and to those who have reactions when exposed to very small amounts. Researchers recommend that at this time, it only be carried out in a clinical setting under trained medical supervision.
What Causes Peanut Allergy?
The science is not clear as to what causes peanut allergy. Both genetic and environmental factors appear to be involved. Family history, occurrence of eczema-type skin rashes, and exposure to soy protein were associated with the development of peanut allergy in childhood in one study. The most current data does not support the theory that, if peanuts are eaten during pregnancy or infancy, there is a greater chance the child will end up with an allergy.
Since peanut oil is pressed from peanuts, some have questioned if a peanut allergy is also an allergy to peanut oil. This question has confused many who would like to enjoy a Sichuan stir-fry, deep-fried turkey, or other foods cooked in peanut oil.
The fact is that highly refined peanut oil is different from peanuts, peanut butter, and peanut flour when it comes to allergy. This is because most peanut oil undergoes a refining process, in which it is purified, refined, bleached, and deodorized. When peanut oil is correctly processed and becomes highly refined, the proteins in the oil that can cause allergic reaction are removed. This makes the peanut oil allergen-free! The vast majority of peanut oil used in foodservice and by consumers in the U.S. is processed and is considered highly refined.
The FDA Food Allergen Labeling and Consumer Protection Act of 2004 and the Federal Food, Drug, and Cosmetic Act (FFDCA) indicate that highly refined oils are not major food allergens.
The Federal Food, Drug, and Cosmetic Act states:
“(qq) The term `major food allergen’ means any of the following:
- Milk, egg, fish (e.g., bass, flounder, or cod), Crustacean shellfish (e.g., crab, lobster, or shrimp), tree nuts (e.g., almonds, pecans, or walnuts), wheat, peanuts, and soybeans.
- A food ingredient that contains protein derived from a food specified in paragraph (1), except the following:
- Any highly refined oil derived from a food specified in paragraph (1) and any ingredient derived from such highly refined oil.
- A food ingredient that is exempt under paragraph (6) or (7) of section 403(w).”
Unrefined, “gourmet,” “aromatic,” or cold-pressed oils may still contain proteins that cause allergy. They can also be referred to as “crude” oils. The use of these specialty oils is limited; however, it should be recognized that not all available peanut oil is highly refined. If an allergic individual is unsure as to whether a product contains or was fried in highly refined peanut oil, that individual should ask the manufacturer or restaurant for clarification.
According to the Food Allergy Anaphylaxis Network, “Studies show that most allergic individuals can safely eat peanut oil (not cold-pressed, expelled, or extruded peanut oil – sometimes represented as gourmet oils).” They recommend that allergic individuals consult a physician regarding whether or not to avoid peanut oil.
One high-quality, controlled human trial published in the British Medical Journal in 1997 looked at the use of refined peanut oil by 60 peanut-allergic individuals. The study monitored individuals with severe peanut allergy and showed they had no reactions to highly refined peanut oil. Researchers concluded that the consumption of refined peanut oil did not pose risk to any of the subjects. Later, in 2000, a study that looked at the allergenicity of refined vegetable oils concluded, “peanut oil presents no risk of provoking allergic reactions in the overwhelming majority of susceptible people.” Additional human trials that test highly refined oils in peanut- and nut-allergic individuals are critical, as this will keep research current and help to corroborate these findings.
How many people have food allergies?
- It may seem like more, but only 4% of adults and 4% of children have food allergies.
- About 90% of food allergies are caused by tree nuts (almonds, walnuts, pecans, cashews, pistachios, etc.), peanuts, milk, eggs, fish, shellfish, wheat, and soy.
What about peanut allergies?
- About 0.6 – 1.0 % of people have peanut allergy, which can vary from mild to severe.
- Nearly 20% of peanut allergies can be outgrown.
- Four times as many people are allergic to seafood than to peanuts.
It seems like more people have peanut allergies, why?
- The prevalence of peanut allergy doubled from 1997 to 2002.
- This increase may be a result of better reporting and improved detection of allergies, which should be diagnosed by a physician.
- The reported increase in peanut allergy mirrors an overall increase in childhood allergies.
Are all peanut allergies severe?
- No, some are mild; however, in those who have severe reactions, ingesting just a trace amount can cause a reaction.
- It is critical to manage peanut allergies, as with any allergy, to avoid severe reactions, such as anaphylaxis.
What is the allergen in peanuts?
- The major proteins Ara h 1, Ara h 2, and Ara h 3 are the allergens in peanuts.
- Smelling the aroma of peanuts cannot cause an allergic reaction.
What about peanut oil?
- Highly refined peanut oil is different from peanuts and from “crude” or gourmet peanut oil because it does not contain peanut allergens.
- Highly refined peanut oil is purified, refined, bleached, and deodorized, which removes the allergic proteins from the oil.
- The majority of peanut oil used by foodservice has been highly refined and processed.
- The FDA does not consider highly refined peanut oil a food allergen.
Click here to see more by downloading the fact sheet on peanut allergy.
To download the full White Paper on Peanut Allergy, click here.