Allergies change how we all eat

Hortense Dodo has genetically engineered a hypoallergenic peanut. But she isn’t targeting people with peanut allergies. Not directly, anyway.

Her peanuts are for everyone else. Dodo wants to see her creation adopted by the food industry so that, in the event of accidental ingestion by an allergic person or cross-contamination, any allergic reaction would be non-fatal. “They don’t have to die from that,” Dodo said.

Her quest began in the 1990s, when she became close to a family whose young child had a very severe peanut allergy. “At that time, I was not aware at all of peanut allergy,” Dodo, who is from Côte d’Ivoire, explained. “But I saw how stringent the lifestyle of this family was. They couldn’t just go eat at any restaurant, they couldn’t have their child sleep over like any other child, the mother had to prepare all food for that child.” When she graduated from Pennsylvania State University with a PhD in molecular biology, she saw an opportunity: If she couldn’t fix the allergy, perhaps she could fix the peanut.

The modern food industry is a story of fixes. We engineered mass production — of crops, of livestock, of processed foods — to nourish people by the millions. We’ve engineered food itself to be more caloric, tastier, cheaper, and more attractive. But it’s mostly been up to the minority of people with potentially lethal allergies to avoid foods that might trigger a severe reaction. We didn’t try to fix foods that caused allergies, in large part because we didn’t think we needed to.

Adobe

That might be changing. Dodo is now the founder and chief scientist of IngateyGen, a North Carolina-based food tech company that is designing the hypoallergenic peanut, using a process that she patented in 2000 while a professor at Alabama A&M University. In the last three years, the company has been able to produce a peanut that is “hypoallergenic straight from the fields,” Dodo said. The company is currently trying to get the approval of government regulators. Its scientists haven’t been able to “officially” taste the product and won’t until that happens. Still, Dodo is confident that candy companies, for example, will see a need for a peanut that won’t inadvertently kill someone.

The problem of the peanut is now even bigger than she could have known back in the 1990s. As Dodo was figuring out how to use RNA interference technology to silence the genes responsible for the proteins that trigger the majority of allergic reactions in sufferers in the early 2000s, the number of sufferers in America tripled. The allergy used to be something that doctors saw infrequently. Today, as many as 2.5 percent of US children have an allergy to peanuts, and that number is rising.

Dodo hopes her peanut will offer comfort to families. “When they send their children to school or out in the world, they know that even if some accident happens, they are not going to be called that their children are dead.”

But the lesson of the hypoallergenic peanut isn’t just that technology is again offering a bright path past our own physical failings. It’s also that the solution to a problem affecting a distinct minority of people sometimes involves everyone. Especially as food alergies become more prevalent, they are bound to change the way all of us eat and live.

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In recent years, we may have given ourselves more food allergies than ever.

Although more than 170 foods are known to trigger allergies, 90 percent of food-related allergic reactions involve just eight food categories: milk, eggs, peanuts, tree nuts, fish, shellfish, soy, and wheat. According to the Centers for Disease Control and Prevention, between 1997 and 2011, the prevalence of food allergies, primarily to the “big eight,” increased nearly 50 percent among children under 18; now, as many as 8 percent of American children have some kind of food allergy, and 30 percent of those have more than one. Meanwhile, adult-onset allergies are also increasing. Now, according to a 2017 report from Brigham and Women’s Hospital, 4 percent of the US population lives with a food allergy, at a cost of $25 billion a year.

Even more surprising is that one in six of those people with allergies have experienced anaphylaxis, a potentially fatal and always terrifying allergic reaction that involves plummeting blood pressure and swelling airways. Researchers from Northwestern’s allergy and asthma team found that insurance claims for anaphylactic episodes related to food allergies increased 377 percent between 2007 and 2016. In all, food allergies are responsible for more than 30,000 emergency department visits annually.

Jonathan Brady/AP

If this sounds like a public health crisis, that’s because it is. “One kid in every classroom has some sort of food allergy,” said Dr. Scott Commins, an allergist and immunologist at the University of North Carolina at Chapel Hill. “You put it on that sort of scale, you realize that we’re dealing with a huge issue that doesn’t seem to be going away.”

The question of why we have food allergies in the first place is one that scientists and researchers are only just beginning to answer.

“We really need more good, basic science in allergy. There really hasn’t been enough,” said Dr. Wayne Shreffler, director of Massachusetts General Hospital’s Food Allergy Center and chief of the pediatric allergy and immunology department. “We’re trying to deal with this rising epidemic sort of with one hand tied behind our back.”

The simplest way to describe food allergy is that it is a misdirected immune response. Our immune systems have evolved to recognize and attack potential immune-threats, such as parasites; people with food allergies, however, produce immunoglobulin E (IgE) antibodies to what are typically harmless proteins, such as those in common foods. No one is born with an allergy, exactly, but once the immune system has decided that a substance is an interloper, a threat, it will continue to perceive it that way, ratcheting up the attacks. In effect, once the antibodies are released, they instigate an internal chemical reaction that typically causes the disturbances to the skin, breathing passages, nose, eyes, and lungs. Though we know what’s happening, Shreffler says, we don’t know why it’s happening — why are our immune systems blasting harmless proteins with the full might of our immune-responses?

Though people have long had food allergies — 5,000-year-old Chinese texts, for example, advise people suffering from skin lesions to avoid certain foods, while Hippocrates noticed that some men suffered badly after eating cheese; one theory claims that Richard III’s strawberry allergy drove him to think that his allies were trying to poison him — this was a very small minority of people. This implies that we’ve always had the genetic propensity to have allergies, but that environmental factors have restrained that propensity. And in the last century, really, the last 50 years, our environment has changed dramatically.

The predominant theory in food allergy for years has been what’s called hygiene hypothesis. The suggestion is that basic advances in sanitation — shoes, purified drinking water, clean homes and plates, toilets — led to a decrease in infectious and parasitic diseases, but an increase in autoimmune and allergic diseases. Underexposure to pathogens, especially early in life, means that our immune systems aren’t being forced to stimulate T cells that would dampen an allergic reaction. Immune systems remain untrained, unable to distinguish between an actual harmful pathogen and a harmless protein.

Supporting this view are data that showing that allergies are on the rise in industrialized Western nations but are not in more rural and less developed nations. Other studies suggest that antibacterial chemicals in common personal hygiene products, including hand soaps and toothpaste, made children more prone to develop food and environmental allergies.

Lately, however, this theory is being narrowed to focus more on what we’re missing: The microbes. We need microbes, the more diverse the better, to outfit our microbiomes — our own little ecosystems. But in recent years, reliance on antibiotics and hormones in both ourselves and in the animals we eat has dramatically changed our microbiomes, reducing the variety of bacterial species we support and that support us, in our guts, airways, and on our skin. This seems to be having a demonstrable negative impact on our immune health, because so much of immune regulation is driven by interactions between us and our microbial hitchhikers. A depleted microbiome increases the probability of allergy.

There are other theories, too. One is that now, our skin is a much more sensitive organ than it was even 50 years ago; new evidence suggests we may be developing allergies from food allergens that we only touch and don’t ingest. Another suggests that the decline of nutrition, of diverse phytochemicals, antioxidants, and vitamins, in our fresh food might be hurting our immune health.

“These are just theories,” cautioned Commins. The real cause likely won’t be just one thing, but a constellation of things. “I think the lesson here is that we have to have a very broad mind.”

Commins was part of the team of researchers at the University of Virginia who cracked the mystery of the strangest allergy yet discovered. Some people exposed to the saliva of a certain tick become allergic to alpha-gal, a complex sugar produced by most mammals (although crucially, not by humans). That means they have an allergic reaction to meat.

Even alpha-gal allergy is on the rise. Once, a single case was bizarre enough to write up and get published in a medical journal. Now, Commins says, he’s seeing five new patients a week. And he predicts we’ll see many other peculiar allergies in the future.

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Food allergies are changing the way we live in a variety of ways, some more subtle than others. Since 2006, food makers have been legally required to clearly list potential allergens on food packaging (for example, identifying “lecithin” as soy). Consumers and regulators want to know what’s in their food and where it comes from.

Other changes demonstrate a culture of enhanced tolerance and awareness around food needs. Burrito chain Chipotle, for example, does not use eggs, peanuts, tree nuts, mustard, shellfish, sesame, or fish in its food. In July, Southwest Airlines became the first airline to stop serving peanuts after a 9-year-old boy went into anaphylaxis on a flight when a flight attendant passed out peanuts a few rows away; Southwest, incidentally, had been the first airline to serve peanuts on board, back in 1970.

Schools, since the beginning of the epidemic, have been driving allergen exclusion practices, in large part because children are both disproportionally affected by food allergy and in less control of the food they eat; a 2018 survey of US school districts found that 17.7 percent of them banned certain foods districtwide, with peanuts topping the list. Allergic Living magazine launched in 2005 and is still in existence.

Washington Post photo by Calla Kesslert

“Society is adjusting to the greater number of people who have food allergies,” said Dr. Scott Sicherer, director of the Jaffe Food Allergy Institute at the Icahn School of Medicine at Mount Sinai in New York. “You’ve got servers in restaurants saying, ‘I’m here to take your order, does anyone have any food allergies?’”

Fueling the growing social awareness is a blossoming industry designed to serve people with intolerances, allergies, and dietary needs. In 2016, the US gluten-free industry was worth $4.3 billion, catering to the roughly 8 percent of North Americans then following a wheat- or gluten-free diet. It’s only grown since. “The food on our shelves is so different from even 15 years ago,” Commins said. More people dealing with food allergies or intolerances means more people to spend money on alleviating them.

But the rapid growth of this industry has also ignited criticism, consistent with a tendency to conflate food sensitivity with weight-loss fads or dismiss it as a bow to trendiness. Meanwhile, the blacklisting of popular foods in schools and elsewhere makes a lot of people very angry. Others worry, as Sophie Egan did in the Washington Post, that “the afflictions of the minority are starting to determine the options for the majority.”

Complicating the discussion is evidence that strict avoidance of certain foods isn’t the best policy for people with allergies. In 2000, the American Academy of Pediatrics advised parents not to introduce peanuts into their children’s diets until after age three. The advice was rescinded in 2008, and reversed in 2017 after a landmark study showed that consumption of peanuts by infants at high risk of developing a peanut allergy actually inhibited the onset of the allergy. But the damage was already done: A 2018 survey of new and expecting mothers found that only 31 percent of them were willing to follow the new guidelines and introduce peanut from age six months.

Egan’s fears are likely overblown. Peanuts and cheese aren’t disappearing from shelves anytime soon — especially since scientific advances may open up new ways of addressing allergies. Some studies have shown that it’s possible to increase an allergic individual’s ability to tolerate their allergen through exposure to smaller amounts. The explosion in genetic-analysis technology could prove helpful, too; a Swiss company is marketing simple, single-use DNA testing kits that allow food manufacturers to test their products to ensure they are nut- or lactose-free.

Another possibility is to approach the problem of food allergies from the other side — by taking out the allergens, as IngateyGen is doing. Dodo believes that her method of genetic engineering could be applied to other allergenic foods, including soybeans and wheat. Commins, the North Carolina researcher, holds out hope that an alpha-gal deficient pork safe for meat-allergy patients could someday hit the market. “Are food allergies,” he asks, “really changing the foods? I would hope that in two years, I could point to this and say yes.”

A holistic, complex problem like food allergies requires creative solutions. But it’s also worth sounding a note of caution. The thread of unintended consequences is woven tightly into the story of food allergies, from our first sips of purified water to the policies of avoidance that might have actually made our allergies worse. As we engineer our way out of this problem that we seem to have made for ourselves — and develop foods to be consumed by everyone, not just people with allergies — we’ve got to be careful.

“I think we have to be humble about our likelihood of producing unintended results,” said Shreffler, “and our limited understanding of these systems that we’re trying to manipulate.”