Your Guide to Food Intolerance

If you suffer from bloating, stomachaches, an irritable bowel, and headaches, you may have a food intolerance, also known as non-allergenic food hypersensitivity. People with food intolerances have difficulty digesting certain foods and it can be tough to figure out which foods your body can't tolerate.

Food Intolerance vs. Food Allergy

Food intolerance is different from a food allergy, which triggers the immune system and elicits a histamine response. There is no histamine response with a food intolerance. The symptoms of food intolerance take longer to set in than symptoms of allergies, which typically occur almost immediately, even if only a tiny amount was consumed. With food intolerance, a small amount of food won't generally produce symptoms. The symptoms of food intolerance and allergies tend to overlap, but the symptoms of food intolerance generally take up to several hours — sometimes as long as two days — to appear, and they may persist for several hours.

Symptoms of Food Intolerance

The most common foods associated with food intolerance include dairy products, gluten from grains, and foods that leave you gassy, such as cabbage or beans. Symptoms that may indicate an intolerance to these or other foods may include:

• bloating
• stomach ache
• irritable bowel
• headaches, including migraines
• cough
• runny nose
• feeling poorly in general

Supplements that aid digestion may help your body digest certain foods to help ease the symptoms.

Causes of Food Intolerance

A number of causes may be the culprit behind food intolerance. In some cases, you may lack an essential enzyme that helps you digest certain foods like dairy products. In other cases, a particular chemical in a food — such as amines in cheese or caffeine in coffee or soft drinks — may cause intolerance. Foods that contain salicylates, which occur naturally in plants, may also cause food intolerance. These foods may include fruits and vegetables, spices, tomato sauce, and tea. Additives like artificial flavorings and colorings, emulsifiers, preservatives, and sweeteners may also cause intolerance.

Figuring Out a Food Intolerance

It's not easy to figure out what type of food intolerance you have. The best way to narrow it down is to keep a food diary containing everything you eat and at what time, as well as what symptoms you experience, and when. By looking at the patterns, you can identify what foods might be the culprit. Remove these possible culprits from your diet one at a time, for two weeks at a time. If you don't experience symptoms while you're not eating the food, you've probably found the problem. If you continue to experience the problems, try excluding the next possible culprit. Continue this until you've identified the source of your food intolerance.

Once you've identified the source of the intolerance, you may be able to improve your tolerance for the food by staying off it for a while and then reintroducing it in very small amounts.

If your symptoms don't improve, schedule a visit with your doctor. While lactose intolerance and celiac disease — which is related to gluten — can be diagnosed by your doctor, general food intolerances cannot. Your doctor may order a couple of tests, such as a skin prick test or blood test — to rule out a food allergy.