It's not crazy to say you have a food intolerance

Being intolerant to a food isn't the same as having an allergy — but that doesn't mean it's not a real condition.

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No dairy. No gluten. No sugar. That’s just for starters. For people with food intolerances, eating can sometimes be more fraught than fun. But if you’re someone who has a food intolerance, or suspect you may have one, you should know that you are far from alone — or crazy. Increasingly, the medical and scientific communities have come to terms with the fact that someone with a food intolerance isn’t simply a picky eater. Any expert will also tell you that a food intolerance isn’t the same as a true allergy, even though many laypeople (and headline writers) use the terms interchangeably. Some of the symptoms may be similar, but there are critical differences.

According to the American Academy of Allergy Asthma & Immunology, if you have a true food allergy, your immune system overreacts to a particular protein found in that food. In other words, it treats that food as an invader and combats it as it would a virus, say, or an infection. Symptoms can occur when coming in contact with just a tiny amount of the food and can range from mild (nausea, hives) to severe (repeated projectile vomiting) or life-threatening (anaphylaxis). The Australasian Society of Clinical Immunology and Allergy says 1 in 20 children and in about 2 in 100 adults have food allergies.

The number of people with allergies seems to be rising, as is the number of foods to which they are allergic.

That said, people also tend to overestimate the extent of food allergies, according to a 2006 piece in the scientific journal EMBO Reports. “The rates of perception of food allergies are often up to four times greater than the rates of true food allergies, because people confuse allergy with intolerance or even cases of mild food poisoning.”

A food intolerance is triggered not by the immune system but by the gastrointestinal tract. The primary “intolerance foods” are those that contain lactose, gluten, and fructose, according to the American College of Gastroenterology, and in the interests of time and space, that’s what I’ll focus on here.

The causes of food intolerance are unclear; increased consumption of ingredients such as wheat and fructose in processed foods is just one hypothesis of many. The estimates of people with a sensitivity to at least one food vary greatly, but precise, comprehensive data is hard to come by, because many studies rely on their subjects' self-reporting of sensitivities to various foods.

In general, the best way to test for a food intolerance is with an elimination diet—that is, you stop consuming the likely culprits until your symptoms disappear, then reintroduce them one at a time. Check with your doctor before beginning so you go about it the right way: Often people don’t eliminate a food for long enough, or if you suspect gluten is the problem, then it’s important to first rule out celiac disease, an autoimmune disorder. To be tested for that, you cannot be on a gluten-free diet. If you suspect you have a lactose or fructose intolerance, your doctor can administer a breath test to confirm the diagnosis. Why is that important? Self-diagnosis can lead to an unnecessarily restricted diet and inadequate nutrition, especially in children.

As for the food-intolerance tests that have proliferated online, well, they can cost (many) hundreds of dollars, and what—did you fall off the turnip truck yesterday? “When it comes to food-intolerance testing, blood tests are just the start,” wrote Scott Gavura on the Science-Based Medicine blog in 2012. Other tests hawked online include “vega testing, the K-Test, hair testing, and applied kinesiology.”

“These tests lack both a sound scientific rationale and evidence of effectiveness,” he wrote, noting that in light of the lack of clinical relevance and the potential for harm resulting from their use, allergy and immunology organizations worldwide advise against the use of blood testing for food intolerance.

Lactose intolerance

This is a reaction to lactose, a milk sugar. To digest lactose, you need an enzyme called lactase, which is produced in mammals at birth. After weaning, lactase output in all mammals, including most humans, slows down, then disappears. Why it does so is a question that intrigues the evolutionary biologist Marlene Zuk, and you can read more about that in a column from 2013. Milk and dairy products top the list of foods that Australians avoid due to allergies and intolerances. Symptoms of dairy intolerance gas, bloating, nausea, abdominal cramps, and/or diarrhea when people consume dairy products. Because most adults in the world are lactose intolerant, many scientists would prefer that everyone stop using the term, as it implies an abnormal condition. The term lactose persistent, which describes the approximately 35 percent of the world’s population who carry that trait, is more to the point.

Dealing With It: No mammal (including humans) past the age of weaning needs milk. As the NYU nutrition professor Marion Nestle likes to say, it’s not a nutrient but simply a food — one you can choose to eat (in many delicious incarnations) or not. Dairy contributes calcium to our diets, but according to Nestle, if you eat plenty of fruits, vegetables, and whole grains, you can have healthy bones without having to consume dairy foods.

If you want to keep milk in your life in some form, switch to a low- or no-lactose version, or give plant milk or A2 milk a try. Some people swear that a lactase-enzyme supplement, taken with your first sip, can aid in digestion of lactose. It’s worth noting that buttermilk, goat’s milk, and aged and hard cheeses are all lower in lactose than cow’s milk, thus easier to digest. Last, even though yogurt and dairy kefir both contain lactose, their probiotic cultures help break it down, and some lactose-intolerant people can enjoy those foods without a problem.

Gluten intolerance

Gluten is a protein found in wheat, spelt, rye, triticale and barley. (Note: Food Standards Australia New Zealand defintes oats as a gluten-containing grain. For more information, see the Coeliac Australia position statement on oats and the gluten-free diet. ) It’s what gives dough elasticity, enabling it to rise. What’s tricky about gluten, though, is that it’s in foods that you’d never find in the supermarket bakery aisle — any number of processed foods contain small amounts of gluten as a thickener. If you think you may have a gluten intolerance, you’ll want to check coeliac disease off the list (the symptoms are similar) before eliminating gluten from your diet (see above).

Dealing With It: There’s a whole world of gluten-free bread, pasta, and cereal options out there, including corn, quinoa, millet and a rainbow of rice varieties. You must read labels and ingredient lists with an eagle eye. “Wheat-free” doesn’t mean “gluten-free”, for instance; the product may still contain oats, barley and/or rye.  There are also myriad forms gluten may take (such as malt flavoring, dextrin, or caramel) in an ingredient list. You’ll also want to avoid beer and other beverages that contain wheat or barley.

Fructose intolerance

This simple sugar is found naturally in fruits, vegetables, and honey. However, you’ll also find it added to everything from refined grain products to baby food. Baby food! Let’s all pause for a spot of collective fuming.

OK, where was I? There are two types of fructose intolerance. Hereditary fructose intolerance is usually diagnosed in childhood and is relatively rare, thank goodness. It’s a potentially life-threatening disorder in which a person lacks the enzyme needed to break down fructose. Dietary fructose intolerance (also known as fructose malabsorption), which is more common, tends to appear in adults and may be triggered by stress or inflammation. If you think you may have irritable bowel syndrome, you may want to ask your physician about fructose intolerance, as up to 70 per cent of patients with IBS have an intolerance of normal amounts of fructose. Breath tests are available for fructose malabsorption. 

Dealing With It: Avoid foods and drinks sweetened with high-fructose corn syrup and other sources of fructose. The low-FODMAP diet is an effective tool for dealing with fructose intolerance.

 

This article originally appeared on takepart.com. Read the original here.