Peanut allergy is tough nut to crack

The Baltimore Sun

They are on a quest to build a better peanut, one safe enough to spread on the sandwich of even the most allergic child.

With peanut allergies on the rise, the race is on in laboratories, farm fields and medical clinics. Nobody has broken through, but promising research is being done on several fronts as scientists try to turn the potentially lethal legume into something everyone can eat.

"A lot of people are starting to try to get into the field because of the urgency," said Soheila J. Maleki, a research scientist with the U.S. Department of Agriculture in New Orleans.

Some researchers, like Maleki, are digging into the genetics of the peanut, trying to breed a harmless variety. Other scientists are treating the peanuts after they have been pulled from the ground, trying to erase what makes some people so sick.

Doctors and parents of allergic children say none of this is likely to assuage the fear that a child could end up in the emergency room after ingesting even trace amounts of the chemicals tucked into the proteins of the legume. Instead, they would prefer the focus be on finding a cure for the allergy, one that could be in its early stages in the form of a vaccine to be tested next year.

Some figures have shown that food allergies - peanuts included - have doubled or tripled in the past decade. One of every 100 children in the United States has a peanut allergy. Some will outgrow it, but there are many adults who are also forced to stay away from peanuts.

The reasons for the increase have eluded doctors. Meanwhile, interest in learning as much as possible about peanut allergies has grown. The National Institute of Allergy and Infectious Diseases nearly quadrupled the amount spent on peanut allergy research in the past five years to $3.5 million last year. In 2005, the institute established a food allergy consortium, promising to spend roughly $17 million through 2010, with a peanut initiative as its first project.

A decade ago, there was little help for parents whose children were found to be allergic to peanuts; now they have support groups, Internet chat rooms and social networks to navigate everything from which restaurants are safe to how to teach your kindergartner to carry a life-saving dose of a form of adrenaline. Food labels didn't always divulge every ingredient inside the box, but today it's no longer a deadly guessing game as to whether peanuts or their residue might be surprise ingredients in unlikely food products.

Lissa Roberts is enthusiastic about the latest research but skeptical. Her 7-year-old daughter, Reagan, is off-the-charts allergic to peanuts, milk and eggs.

"I think it's really neat that people are exploring options," the Ellicott City woman said, "but I don't think it does anything for us because they can't guarantee it won't be free of [all allergens] and that's too big a risk for us.

"I love that people are trying to find ways to solve this problem because it's hard to live this way."

Roberts must be hyper-vigilant about everything her daughter eats. It's especially hard when Reagan leaves the house. There is always a chance that she will eat something that will trigger a frightening allergic response.

Peanuts can cause an overreaction of the immune system that can keep someone from being able to breathe. While other food allergies, such as milk and egg, are more common, peanut allergies are considered among the most dangerous because of the severity of the reactions. Food allergies cause roughly 125 deaths a year, the majority of which are blamed on peanuts.

Mohamed Ahmedna, a food scientist at North Carolina Agricultural and Technical State University, has been in the news after claiming that he has found a way to eliminate all traces of allergen from harvested peanuts. The university announced the feat late last month without disclosing proof.

Ahmedna had been working on ways to make use of the residue of peanuts after they are pressed for oil. He had developed antioxidants from peanut skins that can be put into food supplements, a low-fat, high-protein meat substitute from de-fatted peanut flour and even an infant formula for developing countries.

But the entire endeavor was limited because of the growing incidence of peanut allergy. Ahmedna and his colleagues have been experimenting with different methods - enzymes, fermentation and more - to make peanuts allergen-free. He won't disclose the successful method other than to say it is "food-grade," meaning safe to eat.

In the lab, treated peanuts are missing 100 percent of the allergens, he said. They taste and look like standard peanuts, and he said that his technique can be easily incorporated into peanut butter processing, for instance. But they have not been tested in animals or in people, something that postpones any appearance on shelves for years.

"We can't claim it's allergen-free until it's proven in humans," he said.

Despite the university's news release saying that the process is "believed to be a first for food science" and that it could "be an enormous boon to the [$1 billion U.S.] peanut industry," Ahmedna said, "I can understand the skepticism because it's a problem that's been around for a long time."

Finding a way to build a better peanut has been difficult because of the legume's very properties. The meat of a peanut is primarily protein. And a peanut doesn't have just one protein that would need to be dealt with; it has several different ones that are allergens. Each allergen would have to be turned off individually.

The USDA's Maleki has tried to do just that through breeding. She is working to devise a hybrid peanut with as few allergens as possible. She has found two different peanuts that are each missing a major allergen and is trying to cross those to make an even less allergenic peanut.

The process has been excruciatingly slow. Her colleague in the project, crop scientist Thomas G. Isleib of North Carolina State University, calls it a "long shot."

The mutants don't grow as well as standard varieties, and it takes several generations to see if the plants have kept their new properties. The research was halted two years ago when the plants that Maleki was studying in her New Orleans facility were lost to Hurricane Katrina. Maleki and her colleagues have been back in their labs for only a few months. But now they know which peanuts to cross. They just have to give nature time to grow them again.

"Her outlook on this is any reduction [of allergens] is good," Isleib said. "I take a more conservative view that we need to get rid of all of them. I tend to view this as a long-term approach that may not pay off."

Dr. Robert Wood, a pediatric allergist at the Johns Hopkins University and a leader of NIAID's food allergy consortium, is also cautious. "I don't think any of those strategies to manipulate the peanut will even remotely be the answer," he said.

Wood and other allergists around the country are instead attempting to change the human response. They give minute amounts of peanut to the allergic, slowly increasing the dose until the person can tolerate accidental ingestion without a harmful response.

Others are looking into whether advising the very young to avoid peanuts doesn't actually contribute to the higher prevalence of peanut allergies.

Wood, who has a peanut allergy himself, said he looks forward to seeing the results of that and other studies, predicting there might be a cure for peanut allergies in the next 15 to 20 years.

Isleib, the crop scientist, said the publicity surrounding the announcement of an allergen-free nut appears premature. The process is being kept secret, as a patent is pending, and other scientists haven't reviewed it. Tests on humans and animals have not yet been designed.

"There's glory in this and there may be money in it, but people may be jumping the gun a bit," he said. "If it works, it's going to be big."

Food allergy facts

Food allergy occurs in 6 percent to 8 percent of children under the age of 4 and in 4 percent of adults. The risk is greatest for a child born to parents who are both allergic.

Peanuts and nuts that grow on trees cause most cases of severe food allergy reactions.

Proteins in peanuts and a few other foods can produce an abnormal immune response in susceptible people. The person generates an antibody that stands ready to interact on the molecular level with the specific protein. When it is present in the body, cells are activated in sites such as the nose, throat, lungs, skin and gastrointestinal tract. The cells release chemicals such as histamine that cause the reaction.

Reactions to food substances trigger roughly 30,000 episodes annually of anaphylaxis, a condition that can include itching, fainting and even death.

[Source: National Institute of Allergy and Infectious Diseases]

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