House CallApr/May 2013 Issue

Research Roundup: Chlorinated Water and Food Allergy, Allergic to Spice, and More!

Chlorinated Water and Food Allergy

Dichlorophenols—chemicals widely used for chlorination of water and in pesticides—may contribute to food allergy risk, according to researchers at Albert Einstein College of Medicine in New York. The team there used data from a large national health survey to investigate dichlorophenol exposure and food allergy in 2,211 U.S. children and adults. Those with the highest levels of dichlorophenols in their urine had higher odds of being sensitized to one or more food allergens. It’s not completely understood how these chemicals could affect allergic sensitization.

“Since dichlorophenols have a potent bactericidal effect, it is possible that they can modify healthy bowel flora,” says lead study author, Elina Jerschow, MD, MSc, FACAAI. “Changes in bowel flora were reported to be associated with more allergic predisposition in children.”

Bottled water may offset some exposure. However, researchers emphasize that their study doesn’t prove a cause-and-effect relationship. In fact, the study is the first to link dichlorophenols with food allergy risk. More work is needed to confirm an association.

The study was published in December 2012 in the Annals of Allergy, Asthma and Immunology.

Allergic to Spice

Spice allergy is thought to be responsible for approximately 2 percent of food allergies, although it’s probably underdiagnosed due to the lack of reliable skin and blood tests. According to allergist Sami Bahna, MD, spice allergy should be suspected in individuals who have multiple reactions to unrelated foods or those who react to foods when commercially prepared but not when cooked at home. Bahna, who is past president of the American College of Allergy, Asthma and Immunology, presented an update on spice allergy at ACAAI’s annual scientific meeting in November 2012.

Cinnamon and garlic are common allergy triggers but anything from black pepper to vanilla can cause an allergic reaction. Avoiding spices can be a challenge. They’re present in most packaged foods and can appear in cosmetics and personal care products like toothpaste. Spice content isn’t regulated by the FDA, which means it may not be noted on food labels.

Quinoa Allergy

The first case of quinoa allergy in the United States was recently reported by a team at Saint Louis University in Missouri. Doctors there treated a 29-year-old woman who experienced hives, lip swelling and a “choking sensation” within minutes of eating a quinoa salad. Weeks later when she reacted again, this time to plain quinoa, allergists prepared an extract of quinoa for skin-prick testing and subsequently confirmed a positive result.

Quinoa is considered a fruit but its seeds are often prepared as a pseudo-grain. Nutritious and gluten free, quinoa has been rising in popularity in the United States.

The case report was published in December 2012 in the Annals of Allergy, Asthma and Immunology.

Food Allergy Bullying

Researchers from the Jaffe Food Allergy Institute in New York say bullying is common among food-allergic children. They recently surveyed 251 food-allergic children and their parents about bullying. Some 32 percent of children and 25 percent of parents reported bullying specifically due to food allergy, often involving threats with food (i.e., throwing food at the child). Bullied children reported more anxiety and worse quality of life than non-bullied children, regardless of the severity of their allergy. However, when parents were aware of bullying—about 50 percent of the time—children reported less anxiety and better social and emotional functioning. Researchers say their findings lend support to the recommendation that to reduce the impact of bullying, parents should “help the child identify bullying, as well as how and to whom to report it.”

The study was published in December 2012 in Pediatrics.

Wheat Sensitivity

The condition, “non-celiac gluten sensitivity,” is being accepted by an increasing number of physicians as an actual medical entity—but many questions remain, including what to call it. Recently, a group of researchers in Italy began referring to it as “wheat sensitivity,” since the average person on a gluten-free diet is eliminating wheat.

“We know gluten-sensitive patients experience symptoms when they eat wheat but no studies have clarified what this component is,” says Antonio Carroccio, MD, of the Hospital of Sciacca in Italy. “Gluten is only one component of wheat.”

Recently Carroccio led a study to better define wheat sensitivity. He and his colleagues looked at 276 patients diagnosed with wheat sensitivity via the gold standard method—a double-blind placebo challenge. Two distinct patterns were apparent: patients either had characteristics consistent with multiple food sensitivities, such as a history of food allergy early in life and other food sensitivities, or they had more celiac-like characteristics (anemia, weight loss and the genetic markers for celiac disease). Whether some of those in the celiac-like group may go on to develop celiac disease should be studied in the future, say researchers. But for now, the findings support the theory that wheat—or gluten—sensitivity isn’t just one disorder but probably a variety of conditions rolled into one.

The study was published in December 2012 in the American Journal of Gastroenterology.

“Gluten Free” Food Safety

Europeans with celiac disease can feel good about eating foods labeled “gluten free.” When researchers sampled some 205 gluten-free products from Italy, Spain, Germany and Norway, 99.5 percent of them contained less than 20 ppm—the European Union’s current definition of “gluten free.” Only one product missed the mark, coming in at 27.8 ppm.

Results suggest that the FDA’s proposed (but not yet finalized) less-than-20-ppm standard should be feasible for U.S. food manufacturers. Although individual sensitivities vary, most celiac experts support the less-than-20-ppm threshold as safe for the majority of those with celiac disease.

The study was published in January 2013 in the American Journal of Clinical Nutrition.

Infections Raise Celiac Risk

Having three or more infections during the first six months of life appears to increase the risk of later developing celiac disease, report researchers from Umea University in Sweden. According to their study, the risk of celiac disease was highest when infants experienced multiple infections and were introduced to gluten in larger versus smaller amounts.

Researchers obtained data on infections, infant feeding and the children’s general health from questionnaires completed by the parents of 373 youngsters with celiac disease and 591 without it. Of note, the type of infection—from the common cold to gastroenteritis (stomach bug)—wasn’t as important as the overall number of infections when it came to celiac risk.

It’s not known exactly what causes celiac disease but a combination of genes and environmental triggers, in addition to gluten, are thought to be important. Infections early in life may alter the developing microbiota, the mix of microorganisms normally present in the gut, which could, in turn, affect intestinal immune responses, explain researchers. Antibiotic use to treat these infections could also play a role, they add.

The study was published in December 2012 in BMC Pediatrics.

Medical writer Christine Boyd lives in Baltimore.

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