Maybe you’ve seen or heard about wellness centers that offer food sensitivity tests, which claim to diagnosis if your body is intolerant to certain foods, such as dairy or gluten.
It’s true that many people do struggle with food allergies or a food insensitivity, explains Dr. Benjamin Davis, an allergist and clinical assistant professor at the University of Iowa Hospitals and Clinics.
However, the food sensitivity tests offered commercially today are considered unreliable, often resulting in false positives, Davis says.
“They really have no scientific backing,” Davis says. “If you suspect that foods are part of (your) problem ..., then going to your general doctor to talk things through is one of the first steps.”
Davis explains that food allergies are different than a food sensitivity or intolerance, although they often get confused.
Many times, when someone tells you they are allergic to a certain food, they actually may have a food intolerance, Davis says.
With food allergies, a person’s immune system overreacts when it is exposed to the allergen, Davis says. Symptoms may include hives, wheezing, shortness of breath or swelling of the lips or tongue within minutes of eating the food. Food allergies can be fatal in extreme cases.
The most common food allergens are dairy, wheat, egg, soy, seafood and nuts. These foods are responsible for 95% of food allergies, Davis says.
Although food allergies can develop in older patients, most people who have food allergies are kids, many of whom will grow out of these allergies over time, Davis says.
In comparison, people who have a food intolerance, such as lactose or gluten intolerance, may lack the necessary enzymes to digest the food, Davis explains. Symptoms may include diarrhea, bloating or weight loss.
Celiac disease is a severe form of gluten intolerance, Davis says. People with celiac disease experience an aggravated immune response if they consume any foods containing gluten, or wheat products.
Davis recommends scheduling an appointment with your primary care doctor if you suspect that you or a family member may have a food allergy or food intolerance.
An allergist can test to determine if your body produces certain antibodies, known as IgE antibodies, when exposed to a food allergen. In comparison, the commercial food sensitivity tests offered by wellness clinics test for IgG antibodies.
However, research has shown that IgG antibody tests aren’t reliable and have an extremely high false positive rate, Davis says.
“What we think is going on is ... the (IgG) test is picking up hints of an (immune) reaction. But we think that’s just a normal part of our intestine’s immune response. And in some cases, actually, there’s a subtype of IGG that blocks severe allergic reactions. So you can think of it as a type of reaction that you would want to have,” Davis says.
Studies have also shown that eliminating certain foods, such as dairy or gluten, based on an IgG food sensitivity test doesn’t benefit to patients’ health, Davis says.
Only an allergy doctor can determine if you’re experiencing a true food allergy, Davis says.
If testing shows that you don’t have a food allergy, your doctor may recommend keeping a food symptom diary to try to identify connections to what you are eating and any symptoms, Davis says.
“If they can make any connections, then we recommend doing a two-week elimination diet followed by a two-week reintroduction diet. And then if they make a strong connection there, then they’ve found some answers that they can go off from,” Davis says.
Davis also recommends visiting your doctor if you’re thinking of eliminating certain foods from your diet. When you cut out a specific food group from your diet, you’re at risk for a nutritional deficiency.
For example, dairy foods are an important source of vitamin D, calcium and high quality protein that are difficult to get from other foods.
Davis says research has found that some people who are lactose intolerant can slowly reintroduce dairy foods into their diet to regain their body’s ability to digest dairy.
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