Allergic or Intolerant?

Food allergy and food intolerance differences explored

/ Author:  / Reviewed by: Joseph V. Madia, MD

Does your stomach get a little rumbly after eating certain foods? It’s pretty obvious that pigging out on pizza, ice cream, candy and French fries may give you a stomach ache, but what about when symptoms develop after more typical meals?

It may be that a food allergy or food intolerance is at play.

There are many people with both food allergies and food intolerances, but the distinction between the two is important. Knowing which if either is at play can help you cope with the issue and treat it properly.

In fact, according to the American Academy of Allergy Asthma and Immunology (AAAAI), “Eating a food you are intolerant to can leave you feeling miserable. However, if you have a true food allergy, your body’s reaction to this food could be life-threatening.”

Important Immune Distinction

According to a Mayo Clinic article written by James TC Li, MD, PhD, Mayo Clinic asthma and allergy specialist, when a reaction to food develops, it is most commonly a food intolerance as opposed to a true food allergy.

AAAAI reports that a food intolerance occurs within the digestive system itself when the body is for some reason unable to correctly breakdown and digest the food.

In cases of a food allergy, the reaction develops due to processes in the immune system, not the digestive system.

As AAAAI explains it, when people have an allergy to peanuts, for example, their bodies identify peanuts as an invader. The immune system overacts and produces antibodies that travel to different cells, releasing chemicals and eventually causing an allergic reaction to develop.

A true food allergy causes an immune system reaction that affects numerous organs in the body.

”It can cause a range of symptoms,” wrote Dr. Li. “In some cases, an allergic food reaction can be severe or life-threatening. In contrast, food intolerance symptoms are generally less serious and are limited to digestive problems.”

The AAAAI agreed, reporting that some people with food intolerances can eat small amounts of the food in question without experiencing symptoms or discomfort. However, “a food allergy can cause a serious or even life-threatening reaction by eating a microscopic amount, touching or inhaling the food,” reported AAAAI.

Symptomatic Seperation

As previously mentioned, in patients with food allergies, consuming a tiny amount of the food, coming into physical contact with it, or even breathing particles of it into their body can cause immediate reactions. These symptoms may involve the skin, the digestive system or the respiratory system.

According Dr. Li, patients may experience nausea, diarrhea, stomach cramping, vomiting, hives, tingling in the mouth, swelling on the face, in and around the mouth or of the throat.

Anaphylaxis, a life-threatening allergic reaction, may also occur. These cases may involve dizziness, trouble breathing and loss of consciousness, reports AAAAI.

By contrast, symptoms of food intolerances typically develop more slowly and are less severe. Symptoms may vary greatly from patient to patient but typically focus on the digestive tract, including stomach cramps or diarrhea.

People with a food intolerance may also be able to prevent a reaction. “For example, if you have lactose intolerance, you may be able to drink lactose-free milk or take lactase enzyme pills that aid digestion (such as Lactaid),” wrote Dr. Li.

Why Do Food Intolerances Develop?

With food intolerances, the body is unable to correctly break down certain food.  There could be any of a number of reasons behind why this digestive problem occurs.

According to Dr. Li, one reason may be the absence of an enzyme that is needed to fully break down a food. This is the case in people who are lactose intolerant, a common type of food intolerance.

Some people are sensitive to additives added into food products. “For example, sulfites used to preserve dried fruit, canned goods and wine can trigger asthma attacks in sensitive people,” wrote Dr. Li. The AAAAI reports that similar reactions can also occur to chemicals that occur naturally in foods.

Irritable bowel syndrome may also contribute to a food intolerance, reported Dr. Li. This chronic condition often causes uncomfortable digestive symptoms like constipation, diarrhea and stomach cramping.

Dr. Li explained that celiac disease, which develops in response to gluten, a protein present in wheat, is somewhere in-between a food allergy and a food intolerance.

“Celiac disease has some features of a true food allergy because it does involve the immune system,” wrote Dr. Li, “However, symptoms are mostly gastrointestinal, and people with celiac disease are not at risk of anaphylaxis.”

Coping With These Condition

Seeking professional help to confirm if an allergy or an intolerance is at play is an important first step to coping with either condition.

"It is important for patients to work with their doctor to confirm the cause of their symptoms," said John Oppenheimer, MD, fellow of the AAAAI, in an interview with dailyRx News.

Dr. Oppenheimer explained that doctors will closely assess symptoms and perhaps perform tests before making a diagnosis. Afterwards, a plan of intervention will be developed.

"While a food intolerance can result in a significant reduction in quality of life, an allergy to food may be life threatening," said Dr. Oppenheimer. "As a result, in food allergic patients, beyond avoidance, education regarding the proper indications and use of auto injectable epinephrine is a must."

People experiencing potential symptoms of either a food allergy or a food intolerance should discuss the matter with a doctor to correctly and carefully treat the condition at play.

Review Date: 
April 11, 2013