When someone has a food allergy, one bite of the wrong food could actually be fatal. It’s a heavy and terrifying burden. Further complicating matters are persistent myths about food allergies. Nutritionist Carrie Dennett debunks a few.

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On Nutrition

Under the best of circumstances, raising kids can be tough. But figuring out what foods they’ll actually eat and keeping them safe takes on new meaning when your child has a food allergy. While some people unnecessarily take their food choices too seriously — as if they are one bite away from death — when someone has a food allergy, one bite of the wrong food could actually be fatal. It’s a heavy and terrifying burden, especially when it’s your child’s life at stake. Further complicating matters are persistent myths about food allergies. Let’s debunk a few:

Myth 1: Food allergies are rampant

Food allergies are an adverse health effect caused by a specific immune-system response to a given food that happens each time the person is exposed to that food, according to the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health. Food allergy symptoms vary in type and severity, but usually involve the skin, gastrointestinal (GI) tract and respiratory tract. Most symptoms happen less than two hours after eating the food, but “late phase” reactions can happen after several hours, and delayed-type reactions can happen after 24-48 hours.

How many children have food allergies? That’s hard to say. In the United States, it’s estimated that about 5 percent of children and 4 percent of adults have a food allergy, according to NIAID. However, food allergies often get confused with food intolerances. For example, someone might be unable to tolerate the lactose in milk but that doesn’t mean they have a milk allergy. Similarly, someone might not be able to tolerate gluten, but that doesn’t mean they are allergic to wheat.

Research studies that rely on parent reports of child food allergies likely overestimate the true prevalence. In one study, 28 percent of parents thought that their children had adverse reactions to foods, but only 8 percent of the children had reactions when given the food in a supervised setting. In another study, 12 percent of parents reported that their children had a food allergy, but only 3 percent of the children tested positive for one.

The best studies test for food allergies with a medically supervised oral food challenge. Unfortunately, this is expensive and impractical, so most studies don’t use them. One notable exception is the HealthNuts study in Australia assessing 5,300 children — using food challenges as needed — with the aim of getting an objective measure of the prevalence of food allergies from ages 1 to 10.

It is true that food allergies have been on the rise in the past 20 years, and not just because of increased awareness and better diagnosis. The Centers for Disease Control and Prevention has reported an 18 percent increase in food allergies between 1997 and 2007. Why? That’s not entirely clear. Possible factors include increased use of anti-bacterial cleansers and decreases in family size, two things that discourage the development of a robust, thriving gut microbiota.

Myth 2: Skin and blood tests are the final word

Generally, the first step in diagnosing a food allergy is to rule out other food intolerances. The next step will likely be a skin-prick test or blood test to look for reactions involving IgE antibodies. However, these lab tests are better at ruling out a food allergy — some people have measurable IgE antibodies for a specific food allergen but don’t have any symptoms. That’s why a trial elimination diet or a carefully supervised oral food challenge may be used to help confirm a diagnosis.

Myth 3: It’s a good idea to avoid “The Big 8”

Most food allergies in the United States are caused by milk, eggs, peanuts, tree nuts, wheat, soy, fish and shellfish — foods that are nutritious and perfectly safe for the majority of us. According to a 2017 report from the National Academy of Sciences (NAS), current evidence does not support avoiding potential food allergens during pregnancy and breastfeeding or for prolonged periods in infancy. Food allergy is a complicated disease, and researchers still have unanswered questions about what causes them. One thought is that when kids have environmental exposure (through the skin) to potentially allergenic foods, but don’t have dietary exposure, they may be more likely to develop an allergy.

The Learning Early About Peanut (LEAP) study in the UK randomized infants at high risk for peanut allergy due to having severe eczema, egg allergy or both to start eating peanut-containing snacks (but not whole peanuts, due to risk of choking) between 4 and 11 months of age, continuing until age 5. Of the children who avoided peanuts, 17 percent developed a peanut allergy, compared with only 3 percent of the children who ate the peanut snacks. In 2017, NIAID and the American Academy of Pediatrics endorsed these findings in its updated recommendations.

Myth 4: Banning peanuts is enough

As with food intolerances, food allergies affect quality of life. Unlike food intolerance, food allergies can be fatal. For now, the only treatment is strict avoidance of culprit foods and keeping self-injectable epinephrine available at all times. Studies have shown that many people have accidental exposures, often with reactions, sometimes due to cross-contamination in restaurants, home kitchens or school lunchrooms. Unfortunately, school-wide bans on peanuts or other common food allergens can give a false sense of security. Parents need to have a food allergy and anaphylaxis emergency care plan on file with their child’s school and any caregivers. A downloadable PDF version is available at www.foodallergy.org.

Myth 5: Food allergies are for life

Between 65 and 80 percent of people with cow milk, wheat, soy and egg allergies will “outgrow” their allergies by developing a natural tolerance, but peanut, tree-nut and fish allergies typically last for life, with only 10 to 20 percent of people outgrowing peanut and tree-nut allergies. Researchers are investigating specific “desensitization” treatments that would allow food-allergy sufferers to eat the offending food without having symptoms — though they’re currently not ready for prime time, that’s good news for future generations.