Some of the most common complaints allergist Dr. Adam Williams hears about from patients — things such achy joints, fatigue, migraines, hyperactivity and even autism — aren’t caused by allergies.
“Are these food allergies? The answer is absolutely not,” said the Bend Memorial Clinic physician. “Food allergies do not cause those symptoms.”
Williams’ experience highlights the widespread confusion that exists between food allergies and food intolerances. Food allergies happen because the immune system deems a food dangerous and overreacts to it, prompting often life-threatening symptoms like anaphylaxis.
Lots of people see allergists with issues that may actually be caused by food intolerances, which happen when a person has trouble digesting a food. The symptoms tend to be less severe but longer lasting, and commonly include abdominal pain, bloating and diarrhea.
Dr. Steve Tilles, a Seattle allergist and clinical advisory board member for the organization Food Allergy Research & Education (FARE), said lactose intolerance is the most well-known food intolerance.
“Where you eat the food that has the sugar lactose in it and you feel fairly immediate symptoms — certainly within an hour — that are pretty bad … but in fact, it has nothing to do with the immune system. It’s more of a metabolic problem,” he said.
Tests often wrong
Allergists and other providers commonly test for food allergies using a blood test or skin prick test that looks for immunoglobulin E, or IgE, antibodies, the proteins in the immune system that cause allergic reactions to food. Everyone has some level of IgE antibodies, but in people with food allergies, their levels will be much higher.
The tests are far from perfect, though. Between half and 60 percent of blood and skin prick tests performed will produce positive results for allergies people don’t have, according to FARE.
That’s why Williams says a patient’s history is the most important part of an allergy diagnosis. If a child tests positive for an egg allergy, for example, Williams said he’s more likely to suspect the results are inaccurate if the child’s symptoms are hyperactivity and biting kids at daycare than if the child just ate eggs for the first time and broke out in hives.
“Whenever I detect a positive test to a food, I’m always asking myself and usually discussing with the patient that there is a very good likelihood that we’re dealing with a false-positive test,” he said.
Several natural medicine providers in Bend and elsewhere offer a different type of blood test that can detect food intolerances. It looks for high levels of immunoglobulin G, or IgG, antibodies.
Jason Kremer, a chiropractor with Wellness Doctor, a natural medicine and chiropractic clinic in Bend, said patients’ IgG levels coupled with their symptoms determine which foods he tells them to cut to see if they feel better.
“If I see a couple foods and it’s a mild reaction, we might keep it out for three months,” he said. “If it’s severe, we might keep it out for six months.”
For their part, both Williams and Tilles said two weeks is all it takes to determine whether a food causes symptoms.
Kremer instructs patients to slowly add foods back into the diet, paying close attention to whether symptoms recur.
“When you throw gas back on the fire, you’re going to notice something,” he said. “You’re going to have a heightened response and awareness of, ‘Oh wow, it was totally the dairy.’”
But Tilles, the Seattle allergist, said there’s no research that shows IgG tests prove a food intolerance. Ironically, he said studies have shown the opposite: A higher level tends to mean someone is tolerating a certain food.
“It’s correlating more with being desensitized or possibly tolerant,” he said.
In 2011, for example, Italian researchers tested the levels of IgG4, a subtype of IgG, among 73 adults with suspected food allergies or intolerances. Although 45 subjects tested positive for a number of foods — mainly eggs, milk and wheat — none had adverse reactions to those foods when they ate them in double-blind placebo-controlled tests.
The study, published in the International Archives of Allergy and Immunology, concluded that IgG4 tests lack clinical utility for diagnosing food allergies or intolerances.
A small group of kids who recovered from cow’s milk allergies by age 3 showed higher levels of IgG4 than when they were measured as infants, according to a 2009 study in the Journal of Allergy and Clinical Immunology.
Another 2009 study in the same journal detected an increase in IgG4 levels among a group of 27 kids after their peanut allergies diminished compared with before.
That said, Tilles said he doesn’t doubt removing foods like gluten and dairy helps people who have intolerances to those foods. He just doesn’t think the IgG test is detecting those intolerances.
Patients who want IgG testing will likely have to foot the bill themselves. Insurance companies typically don’t cover the test, although they do cover IgE testing. Moda Health reasoned in a coverage explanation that “there is no evidence that IgG antibodies are responsible for delayed allergic symptoms or intolerance to foods.”
The tests the Hawthorn Healing Arts Center uses cost about $250, said Joshua Phillips, a naturopath at the Bend clinic, whose providers offer both IgE and IgG testing for food allergies and sensitivities.
Cutting suspect foods
While providers disagree over the use of the IgG test, they agree on one thing: The best way to learn the truth is to stop eating the foods in question, at least for a time.
“I always like to tell folks that the gold standard, really, is the old-fashioned way of eliminating a food for two weeks or more and waiting to see what happens,” Phillips said.
The tests don’t tell the whole story, Phillips said. If a patient tests positive for eggs, for example, but they don’t get symptoms after eating eggs, he doesn’t tell them to stop eating them.
Williams, of BMC, agreed. If a patient tests positive for an allergy but doesn’t get symptoms from that food, he said it’s appropriate to ignore those results.
Lori Brizee, a registered dietitian with Central Oregon Nutrition Consultants, said when people cut out a food to test for an allergy or sensitivity, she recommends keeping a food diary — her office provides a specific form for this purpose — where they keep track of everything they eat, the time they ate it and, if they had symptoms, what they were and when.
Oftentimes when people cut out a food there is a “honeymoon period” in which they feel better for about a week even if that food wasn’t causing their symptoms, Brizee said. After that, they go back to feeling bad again.
“I think that is absolutely essential,” she said, “because you want to be objective and scientific about what you’re doing.”
Making up for lost food
Kremer, the Bend chiropractor, said he’ll often advise patients to give up gluten even if the tests don’t show an allergy or intolerance — especially athletes, who he has give up both dairy and grains. The tests can miss things, he said.
“Not everybody is going to react to the foods that could potentially be causing a problem,” he said.
Brizee said she has no problem saying goodbye to refined flours, but some gluten-containing foods are very healthy, such as whole grains like wheat berries, kamut, spelt and farro.
If people are giving up gluten, Brizee said it’s important to make sure they’re getting enough fiber from other foods. She recommends nongluten whole grains such as brown rice, millet and quinoa for fiber, as well as vegetables like acorn, butternut and spaghetti squashes, pumpkin and sweet potatoes.
“I’m going to want to replace those carbohydrates you usually get from gluten-containing grains with really healthy starches that don’t contain gluten,” she said.
Whole wheat also provides lots of B vitamins. Brizee recommends eating plenty of legumes to compensate.
Among people giving up dairy, Brizee’s concern is calcium, since foods like milk, yogurt and cheese contain the highest amount of natural calcium of any foods. She recommends compensating with extra greens, such as arugula, kale and broccoli. (The body doesn’t absorb much calcium from spinach.)
“It’s hard to meet 100 percent of your calcium needs without dairy products,” she said.
People can also drink calcium-fortified orange juice, soy milk or almond milk, Brizee said, although she cautions that while almond milk can be fortified with calcium, it doesn’t contain much protein.
As a dietitian, Brizee said she’s concerned patients will become malnourished if they’re eliminating too many healthy foods for intolerance and allergy testing. Wheat, dairy and eggs are some of the most common foods people cut, she said.
“You take all of those out of your diet and it’s like, whoa, you really have to plan in order to have a healthy diet,” she said, “So there are risks.”
— Reporter: 541-383-0304,