The Food Allergy Research and Resource Program at the University of Nebraska-Lincoln has been researching the issue for more than 20 years. Dr. Melanie Downs is an assistant professor with the program. Her research focuses on the identification, characterization, and detection of food allergens. She also works with the food industry on food allergen management. We asked her some of the questions we’ve received at Best Food Facts.

What is the cause of most food allergies?

Dr. Downs: “A food allergy occurs in certain individuals whose immune systems have generated a particular type of antibody — IgE – which specifically recognizes proteins from a particular food. After these IgE antibodies have developed and the person consumes the food in question, interaction of the food proteins with the IgE antibodies will result in the release of substances in the body (e.g histamine), which will cause symptoms of an allergic reaction.”

“While it has been known for many years that food-specific IgE is required to develop a food allergy, it’s still unknown exactly why certain individuals develop IgE against foods and other individuals don’t.  Having food-specific IgE antibodies is necessary for an allergic reaction but some individuals who have such antibodies do not experience allergic reactions on ingestion of the food.”

If someone is allergic to soy, what is the part of the food that causes a reaction?

Dr. Downs: “The food components responsible for soy allergies, like nearly all food allergies, are the naturally occurring proteins in the food. Foods can have a number of different allergenic proteins, and allergic individuals may react to one or more of these allergens.”

If you are allergic to soy, should you avoid foods cooked in soy oil? Find out here.

What are the typical reactions that indicate a food allergy?

Dr. Downs: “The symptoms of an allergic reaction to foods can involve various different organ systems, including the following:

• skin – hives, swelling, eczema
• respiratory tract – runny nose, throat swelling, asthma
• gastrointestinal tract – nausea, vomiting, abdominal pain
• cardiac system – low blood pressure, arrhythmia

“Severe allergic reactions can also result in anaphylaxis, shock, and death. The type of symptoms experienced during a food-allergic reaction can vary widely between allergic individuals and between reactions for a single individual.”

What’s the difference between a food allergy and a food intolerance?

Dr. Downs: “The primary difference between food allergies and food intolerances is that the biological mechanisms for food allergies involve the immune system, while the mechanisms for intolerances do not. In most cases, food allergies are also generally considered to present more severe and immediate health risks than intolerances; sulfite-induced asthma is an exception as it is not an allergic reaction but can cause immediate and severe reactions.”

Do soy allergies usually begin in childhood or later in life?

Dr. Downs: “Soy allergies have historically developed most commonly in infancy or early childhood, which is similar to milk, egg, and wheat allergies. The development of soy allergy in infancy may be related to the use of soy formula as a substitute for milk formula.  As that practice is decreasing, the prevalence of soy allergy in infancy may decrease as well.  It is possible to develop a food allergy later in life as well.”

Are soy allergies becoming more common?

Dr. Downs: “While there is some evidence that food allergies in general are becoming more common, it is difficult to get good estimates of the prevalence of allergies to some individual foods, including soy. If the rates of soy allergy are increasing at all, they do not appear to be increasing any faster than other food allergies.”

What are some common misconceptions about food allergies?

Dr. Downs: “Some consumers with histories of serious allergic reactions do not seek advice from an allergist and do not carry the life-saving drug, epinephrine. They should do both.”

Food allergies are caused when a person’s immune system creates a particular type of antibody. Soy allergies are caused by the protein. Reactions can vary; if you have a serious reaction, consult with a physician.

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According to Dr. Stephen Taylor, no one knows the exact answer to why the prevalence of food allergies is increasing. He doubts any experts would hypothesize that chemicals used in food production play a role in the prevalence of food allergies. He explains other theories that seem much more plausible, but have not been proven, like cleanliness, c-section births and avoidance of specific foods.

Best Food Facts received a reader question asking, “Why is there such an increase in food-related allergies, such as peanut, eggs, and gluten? Could it be the chemicals that are used in the production?” We reached out to Dr. Stephen Taylor, Professor and Co-Director of the University of Nebraska Food Allergy Research & Resource Program, for his expert insight.

Is there an increase in the prevalence of food allergies? Or does it just seem that way?

Dr. Taylor:

“Most experts do believe that there’s a genuine increase in food allergies. Certainly, diagnoses have improved over the last 25 years, so some of the increase may just be attributable to better diagnoses. Even so, there’s been a genuine increase in doctor-diagnosed food allergies as well. Self-diagnosed food allergies are not very reliable.”

Can you explain the difference between food allergy and food intolerance?

Dr. Taylor:

“My definition is that allergies are abnormal responses of the human immune system to naturally-occurring proteins in foods. More than one kind of immune mechanism can be involved. Peanut allergy, for example, has a different immune mechanism than gluten sensitivity. There are also intolerances due to foods that do not involve abnormal responses of the immune system and for the most part, those illnesses have milder symptoms. For example, lactose intolerance leads some people to restrict their dairy product intake, but they don’t have to avoid it nearly as carefully as someone with a true milk allergy.”

Why is there such an increase in food-related allergies, such as peanut, eggs, and gluten?

Dr. Taylor:

“Well, experts really don’t know for sure why there is an increase in food-related allergies, but there are several theories.

• The one that’s gotten the most publicity is called the hygiene hypothesis. It hypothesizes that we’re too clean and, therefore, our immune system doesn’t have very much to be concerned about. Instead, it becomes mischievous and gives us allergies. It’s been very well noted that consumers in societies where hygiene is not that high seem to have lower prevalence of food allergies.
• Another theory that has been pretty clearly demonstrated is the increase in prevalence of birth by caesarean section because a baby born by caesarean does not acquire his mother’s gastrointestinal bacteria during the birthing process. The immunities that the baby might acquire during the birthing process may be quite important in preventing the development of food allergies, so babies born via caesarean seem to be at higher risk.
• Another theory that’s been discussed but has little proof is the change in weaning practices that have occurred over the last three decades. We put a lot of emphasis on avoiding solid foods and weaning babies a little bit later in life, sometimes at 2-to-3 years old. And it seems like a good idea to avoid allergens in food, but that may not be the best course. There’s some evidence that suggests early introduction of certain kinds of solid foods into the baby’s diet may actually promote tolerance of those foods, rather than the development of food allergies. Recently completed research in England indicates that early ingestion of peanuts may help to prevent the development of peanut allergy, but parents should seek advice from their pediatrician or allergist because there are some important caveats to that advice.”

When should parents start feeding certain foods to their children?

Dr. Taylor:

“I suggest following the recommendations set forth by The American Academy of Pediatrics.”

More information on feeding your child:

• Baby Feeding Chart
• Foods That Can Be Unsafe for Your Baby
• Baby Food Allergies
• Introducing Solid Foods at 4-6 Months

General guidelines are to start feeding solid foods at 4-6 months of age, including rice, barley, oats, avocado, apples, bananas, pears, acorn and butternut squash, sweet potatoes, and green beans. Please check with your pediatrician for more information.

Is it true that some allergists have people consume small amounts of foods they’re allergic to in order to build up tolerance?

Dr. Taylor:

“I would suggest that people talk to their allergists before they try that. The allergist may, in some cases, suggest periodically trying the food to see if you’ve outgrown your allergy, but you should do that only with expert advice. It can be a risky proposition as it is really hard to control the dose. It has to be done under expert medical guidance; doing it at home is not recommended.”

If you are experiencing problems you think are associated with food allergies, please visit your physician or allergist.

Image: “lightly roasted peanuts” by Stacey is licensed under CC BY 2.0.

The post Why Has There Been an Increase in Food Allergies? appeared first on Best Food Facts.

Reader question: “Chickens and cows are often fed GM corn and soy – how will they show up in eggs and milk?”

To answer that question, we reached out to two experts, Sally Mackenzie, PhD, Ralph and Alice Raikes Professor in the Department of Agronomy and Horticulture in the School of Biological Sciences at the University of Nebraska-Lincoln and Denneal Jamison McClung, PhD, Associate Director of the Biotechnology Program University of California-Davis.

Sally Mackenzie, PhD:

First, it’s important to note that genetically modified crops have been in the American food supply for over 15 years and there has never been a single food allergy associated with the particular proteins that are introduced by GM. Not one. This is not surprising, however, because genetic engineering regulations in the U.S. require that such tests be conducted before the product is ever on the market. Food allergy tests are not difficult; they are a standardized technology applied regularly in development of GM products.

To explain genetic modification, it simply introduces a new protein to the plant. Proteins are digested and the amino acids (from the proteins) are absorbed into the digestive system. So, there is virtually no way that the GM protein would ever be recognizable by the human system after it has passed through the chicken or cow that ate the GM corn or soybeans. If the protein is not a human allergen in its intact state, there is no reasonable way that it would become an allergen after ingestion by a cow.

Lastly, science has shown us that GM products are not dangerous; there is no evidence of their being dangerous for human or animal health in the many, many years of testing that have been involved. I know of no reasonable and respected scientist in the U.S. or Europe with expertise in GMO technology who believes GM products to be unsafe for human health.

Denneal Jamison-McClung, PhD:

It’s a good question. The nutritional composition of GM crops approved for food and feed have been well-characterized. Through many animal feeding studies, GM feed has not been found to cause physiological or other changes in animals. The allergen content and nutritional profile of milk, meat and eggs obtained from animals consuming GM feed will not be different from animals consuming comparable conventional feed.

Why not? Well, the digestive tracts of animals break down nucleic acids (genes) and proteins into biological building blocks (nucleotides and amino acids), whether these molecules are derived from GM or conventional feed. Movement of whole GM nucleic acids and proteins from GM feed into the milk, meat and eggs of animals that eat GM feed is not physiologically possible.

If you have a question for the experts, please let us know!

_{“Fresh Eggs” by Jake Wasdin is licensed under CC BY 2.0.}

The post Egg and Milk Allergies: GMO Connection? appeared first on Best Food Facts.

To answer these questions, we reached out to Dr. Stephen Taylor, Professor, Food Science & Technology at the University of Nebraska-Lincoln.

Why do my children have food allergies? 

Dr. Stephen Taylor:

If children are thought to have developed food allergies, clinical diagnostic confirmation from an allergist should be sought. Children develop food allergies because their immune systems react inappropriately to specific foods and develop IgE antibodies against specific proteins from those foods. Interaction between the IgE antibodies and those proteins elicit the allergic response. Food allergy development in children is more common than in adults because many new foods are being introduced into the young child’s diet. 

Why have food allergies reached epidemic levels since GMO foods have been introduced to our food supply?

Dr. Stephen Taylor:

The prevalence of food allergies in children has increased considerably over the past 20 years. While this increase is partially coincident with the introduction of GMO foods into the American marketplace, the increasing prevalence of food allergies in children actually began 5-7 years before the introduction of GMOs. Furthermore, the food allergies that have increased the most including peanut, tree nut, egg and milk allergies are foods that are not GMO. The primary GMO foods in the U.S. are soybeans and corn. Corn allergy is and always has been rarely identified. Soybeans are among the most commonly allergenic foods but no evidence exists to suggest that the prevalence of the soybean allergy has increased over the past 20 years.

Could it be that our bodies do NOT digest them just as unmodified foods and that a significant proportion of the population is now having their bodies view many of the foods as foreign substances?

Dr. Stephen Taylor:

The digestibility of the novel proteins introduced into GM soy and corn has been assessed and they are very rapidly digested. No evidence exists that GM soy and corn are harder to digest than conventionally bred soy and corn.

Why is Europe not seeing the numbers of food allergies that the USA is seeing?

Dr. Stephen Taylor:

Europe, at least northern Europe, is seeing the exact same increased prevalence of food allergies as encountered in the USA even though GMOs are largely banned from their marketplaces. The prevalence of food allergies in some southern European countries e.g. Greece and in the eastern European countries is lower than in northern Europe (Germany, Netherlands, France, Denmark, etc.). Currently, this difference in prevalence is well documented but not yet explained.

Note: In 2015, the Food and Drug Administration approved genetically modified apples and potatoes, but these varieties won’t likely be commercially available until 2016.

Do you have a question for our experts? Submit a question here.

View our five-part video series focused on genetically modified food: 

GMO 101 

Are GMOs Safe?

Are GMOs Harmful to the Environment?

Are GM Foods Nutritionally Different?

GM Labeling

_{“peanuts” by USDA is licensed under CC BY.}

The post GMOs and Food Allergies appeared first on Best Food Facts.

The video below explores food safety issues related to GM foods through a conversation between an Illinois mom and blogger, Betsie Estes, and a plant molecular geneticist, Dr. Sally Mackenzie, from the University of Nebraska-Lincoln.

We’re interested in understanding what additional questions you have for Dr. Sally. Feel free to submit questions below or here.

What did other experts have to say about whether genetically modified crops are dangerous to eat?

Do genetically modified foods cause allergies?

Dr. Bruce Chassy:

“All GE crops are subjected to a thorough pre-market safety assessment which includes a systematic analysis of any potential to produce allergies before they come to market. There is no reason to believe that GE crops would give rise to allergies. The claim that they might produce, or have produced allergies, is misleading. There are no valid scientific reports that support this claim.”

Do GM foods undergo human safety tests?

Dr. Chassy:

“Extensive compositional testing is done to assure that there is no loss of nutrients and no introduction or increase in potentially toxic compounds, anti-nutrients, or allergens. The safety of the new trait introduced into the crop is also carefully tested in the laboratory and in animals. Human safety tests are not used on whole foods because they lack sensitivity – just try to get a human to eat a diet that is 30 percent soybeans or 30 percent corn. Food safety experts, nutritional scientists and toxicologists have developed very effective methods for evaluating the safety of foods that are used for all novel foods and ingredients independent of whether they are GE. FDA concluded in 1980 that whole food studies in humans and animals are not recommended since they are of little value in predicting safety.”

Dr. Wayne Parrott:

“It turns out there are much better ways to test for safety. Working with humans is difficult: first, we do not have inbred laboratory strains of humans the way we have rats and mice. Getting humans to eat the same meal for days on end is difficulty, and humans have lots of bad habits (ranging from lack of exercise to getting to bed too late) that can throw results off.”

How can GMOs be safe if they aren’t natural?

Dr. Martina Newell-McGloughlin:

“Biotech products are far safer than other methods that are used to introduce traits and value into crop products. We have been modifying crops for about 10,000 years. And a lot of the older technology is not subject to regulatory review because it is “generally regarded as safe” (GRAS). An example of this is RoundUp Ready soybeans (ones that can tolerate pesticides and herbicides). Before being made available to the public, they were subject to 1,800 tests. Some examples of foods in the modern diet that are also considered GRAS include:

• Wheat used for pasta – the technology came from a nuclear research facility after World War II.
• Asian pears – they’ve been irradiated at a facility in Japan
• Barley, used for Irish beer and Scotch whiskey – comes from corn that was irradiated at a nuclear research facility
• Asparagus – all asparagus consumed today is the product of biotechnology”

Dr. Parrott:

“It’s not a good idea to assume natural automatically means safe. Salmonella, aflatoxins, botulism, poison ivy, strychnine, arsenic, asbestos and lead are all natural substances that are not safe for humans. Although humans have been modifying their food for centuries, the point is that many extra precautions are used when food is modified by biotechnology. These include an extensive series of laboratory and animal safety studies. In contrast, food produced with other technologies is simply assumed to be safe, and no extra testing is usually required.”

What role does GM food have in the increase of food allergies and attention deficit disorder (ADD) in children?

Dr. Parrott:

“There is data from Europe which shows that allergies were on the rise well before the era of GMOs. Furthermore, GMO crops are extensively tested before marketing with a special emphasis to make sure they do not cause allergies. At this point, I cannot think of anything that is uniquely different or uniquely present in GM crops that could be associated with any negative effects on people.”

Dr. Chassy:

“None. There is simply no connection between GM crops and the small increase in food allergy that may or may not be occurring – allergists are still arguing among themselves if it is more allergies or more frequent diagnosis. Those who think allergies are increasing have a theory, also unproven, that raising our children in very sanity conditions may be a factor in allergies. The theory goes that since the food allergy immune response is mediated by the parasite immune system, and we don’t need that system very much because of improvements in sanitation; the idle system sometimes reacts to foods that it normally wouldn’t react to. But that’s just one idea, allergists really don’t know the reason, but no responsible allergist implicates GM crops. Note that reports of allergies increasing started coming in long before the first GM crops were planted. And GM crops are the only types of crops that are actually carefully studied to make sure they don’t cause allergies before they are put on the market, so they are less likely to cause allergies than most foods. The fact is, 90+ percent of food allergies are caused by a few commonly eaten foods: fish, shellfish, milk, wheat, soy, eggs, peanuts, tree nuts. Of those, only soybeans (soy products) are planted as a GM crop, so it’s hard to see how GM crops would be contributing to allergies. There is no evidence of a connection between GM crops and ADD and no sound scientific reason to think there should be. Rates of ADD are also increasing, but doctors think this is because of growing awareness and higher rates of diagnosis.”

None. There is simply no connection between GM crops and the small increase in food allergy that may or may not be occurring
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Still have questions? Submit them below or at here.

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