Food intolerances have received a great deal of press coverage in recent years, which has led to questions about whether a simple food intolerance test can tell you what foods are problematic and which foods are fine for any particular individual.
This sounds great: a test requiring a blood sample that can be taken in minutes, and which can definitively tell you what foods are going to be trouble. Unfortunately, the science doesn’t entirely support this.
What Is A Food Intolerance?
When we talk about food intolerance, we aren’t talking about food allergies such as allergies to peanuts. An allergy is a direct immune response to a food. The body assumes the food is an invasive agent like bacteria and responds accordingly. We can test accurately for food allergies using a test that detects specific antibodies. Unfortunately, when we test for food intolerances, different antibodies are detected. These aren’t quite as specific, so false positives can happen.
A food intolerance is not as harmful as an allergy. Those who are lactose intolerant, for example, are not allergic to milk products. Instead, they lack the enzyme, lactase which permits them to break milk down and digest it. This leads to gas and bloating.
Also, food intolerances can be a result of underlying gastro-intestinal issues. This means that correcting underlying issues can sometimes resolve them. For example, if your gut contains a specfic bacteria that reacts to gluten, sometimes erradicating that bacterial colony with prescription drugs and/or probiotics can resolve the issue. A food intolerance can be a symptom of another condition, too. Sufferers of irritable bowel syndrome may not be able to tolerate onions or garlic, but this doesn’t mean they have an allergy to these foods.
Sometimes “food allergy” and “food intolerance” are used interchangeably, but they are very different. It’s important to note that there are allergy tests that are legitimate and can reveal food allergies. However, when we talk about a food intolerance test, this is not a test for an allergy but for a sensitivity. (Hint: any test that mentions an immune response tests for an allergy, not merely an intolerance.)
Is There A True Food Intolerance Test?
Thus far, scientists have not found a way to perfectly test for specific intolerances. There are simple blood, urine, and stool tests which may show the presence of a food intolerance, but research has been unable to back these up consistently. But this doesn’t mean it’s impossible to solidly determine whether you have a food intolerance. If you’ve been tested for food intolerances and discovered some, a challenge elimination test is a good next step.
The Challenge Elimination Test
The challenge elimination test is a simple way of determining whether you have a sensitivity or intolerance toward a certain food. But while simple, it can be time-consuming. It works like this: remove all traces of the food in question from your diet for a period of time. This can be one week to more than a month – until you have no sign of a reaction to that food. It’s important to remove only the food you are concerned about. For example, if you remove dairy from your diet, and this includes your favorite ice cream (which happens to include nuts) you may be removing your only source of nuts from your diet. And the true issue could be a nut allergy, not an intolerance to dairy products.
If you aren’t sure how to proceed, consult a dietician or nutritionist. He or she can arrange a diet that covers all the bases, but removes the one food you suspect may be causing your reaction.
Once you’ve had a period with no sign of a reaction, introduce that food back into your diet. But be careful not to include anything else. In our example above, if you suspect an intolerance to dairy products, add a small glass of milk to your diet – but nothing else milk-related. (None of that favorite nutty ice cream!) This can give you a relatively definitive answer to the question of whether you have a sensitivity.
What Does The Future Hold?
While there is not a simple, definitive food intolerance test at this time, research continues. And we may see a host of tests available in the near future. So don’t assume that what you find today is the end of the story. There is advanced ongoing genetics research that looks at both human genetics and the genetics of the bacteria that live in your gut. Both of these avenues may yield simple tests for food intolerances and sensitivities.