Food intolerance or food allergy?

Food intolerances are common. But many people confuse food intolerance with food allergies.

Food allergy

A food allergy causes an immune system response that affects several organs within the body. These reactions can vary from moderate symptoms, like developing hives or a body rash, to life-threatening symptoms, such as anaphylaxis, which causes your immune system to release a flood of chemicals that can cause you to go into shock.

Other symptoms of food allergies include:

• Tingling of the tongue, lips or face
• Swelling of the hands, feet, mouth or tongue
• Rapid pulse or arrhythmia
• Fainting or near-fainting spells
• Wheezing or trouble breathing
• Blurred vision

If you experience any of these symptoms, you should speak to your primary care provider or seek emergency care.

Food intolerance

In contrast, food intolerances typically have less serious symptoms and are more commonly related to the gastrointestinal tract. The most common food intolerances are lactose (dairy) intolerance and food additive intolerances, such as MSG or flavor enhancers.

Food intolerance is common. By adulthood, a degree of lactose intolerance develops in the vast majority of persons with African, Asian, Hispanic and American Indian descent. In African Americans, the incidence of lactose intolerance is over 70% by adulthood.

Food intolerances with digestive tract symptoms include:

• Abdominal bloating
• Nonbloody diarrhea
• Excess gas
• Nausea
• Vomiting
• Abdominal pain or cramping

Food intolerance does not cause bloody or black stools, fainting, abnormal heart rates, muscle weakness or seizures. If you experience any of these symptoms, you should speak to your primary care provider.

Tips, treatment for food intolerance

Tests can confirm food intolerance for certain foods or substances. Yet, there is no test for many foods. Try keeping a journal of what you eat, and monitor it for instances when symptoms flare up. You may discover specific foods that cause your symptoms. Try avoiding them in the future. Treatment depends on the intolerance. Typically, lactose intolerance is treated by avoiding or limiting lactose-containing foods or with drug therapy, such as an over-the-counter product.

Since foods with dairy contain phosphorus, calcium, and other important minerals and vitamins, it's not recommended to avoid lactose unless the intolerance has been confirmed with testing. If a tolerance is confirmed, you can then discuss with your health care team whether a multivitamin or additional calcium and vitamin D supplementation are recommended.

If you have concerns or questions about potential food allergy or food intolerance, meet with your primary care provider to determine if an allergist, gastroenterologist or registered dietitian needs to evaluate you.