can you name the top three food intolerances?

Hint: Gluten intolerance, lactose intolerance and ...

Food intolerances seem to be more prevalent than ever before. Maybe it is what has been added to the food we eat, maybe it is that we eat more convenience foods, or maybe it is because we inhale meals to get through our busy lives. Regardless of the cause, we need to know what foods we are most intolerant to and why. To answer these questions, we need to clarify the difference between a food allergy and an intolerance.

An allergy to a food is an immune response. The food particles are seen as foreign invaders, and the immune system springs into action making antibodies and causing inflammation. People who have food allergies suffer from itching and swelling, and some allergies can even be life-threatening.

Intolerances are never life-threatening although they may be socially threatening. Symptoms of intolerances are usually gastrointestinal related and are typically include nausea, gas, bloating, and even diarrhea. Intolerances are usually the result of an enzyme deficiency during digestion. Enzymes are helpers that speed up the chemical reactions required to break down food into its simplest parts for absorption into the blood stream. Eating too quickly can also have an effect on how we tolerate food since we need to help break the food into smaller pieces by chewing and keeping the food in the mouth a little longer to introduce the first enzymes into the system.

The three top food intolerances of today seem to be gluten, dairy, and sugar.

Gluten is a protein in wheat, barley, and rye. Gluten intolerance is more of an allergy. The gluten causes an immune reaction in the intestines that causes inflammation and damage to the tissue, resulting in diarrhea and gas. This intolerance can lead to malnutrition. However, gluten sensitivity is an intolerance causing symptoms like gas and diarrhea but without the intestinal damage.

Dairy has a couple of offending aspects. The protein casein causes an immune response so that is an allergy. The intolerance aspect is to lactose. If lactose does not break down, it travels to the large intestine and becomes food for the millions of bacteria that live there. The bacteria release gases, and the intestines dump in water to help restore order. Avoiding dairy or substituting lactose-free foods can minimize the problems.

Sugar, also known as sucrose, is another common food intolerance. Sucrose needs the digestive enzyme sucrase, produced by the small intestine, to break it into glucose and fructose for absorption. The symptoms of sucrose or sugar intolerance are very similar to those of lactose intolerance, including gas, bloating, abdominal pain, and diarrhea following meals. The bigger challenge with sucrose or sugar intolerance is that avoiding sugar completely is difficult. Unlike lactose, sugar is in most of the foods we consume on a daily basis, like fruits and vegetables, and not just in foods we would specifically call “sweets.”

What should you do if you think you have a food intolerance? First, slow down your eating to allow the enzymes in your saliva to start the process. Then try eliminating all sources of the offending foods for a week or so, and see if your symptoms improve. Then do a challenge where you add the food back into your diet. If your symptoms come back, that’s a pretty good indication that you do not tolerate that food; and therapy options may be needed when consuming those foods.

Do you have sugar intolerance?

If you think you may be suffering from Sugar Intolerance (Sucrose Intolerance, Congenital Sucrase-Isomaltase Deficiency, or CSID), you can try a simple food challenge called the 4-4-4 Sugar Challenge. Follow these three simple steps:

Step 1

Stir 4 tablespoons of ordinary table sugar into a 4-ounce glass of water. Mix until sugar is completely dissolved.

Step 2

Drink it on an empty stomach.

Step 3

See if symptoms, such as bloating, gas, and diarrhea, occur during the next 4 to 8 hours. If so, this suggests sugar intolerance is possible.


1. You may have relatively  SEVERE SYMPTOMS. If you do have sucrose intolerance, this challenge may cause relatively severe gas, bloating, and diarrhea. Please plan to take the challenge on a weekend or other day when GI symptoms will not cause you to miss work or other important events.

2. THIS CHALLENGE SHOULD NOT BE GIVEN TO INFANTS, VERY YOUNG CHILDREN, TO PEOPLE WITH SEVERE SYMPTOMS, OR THOSE WHO ARE DIABETIC. You and your doctor should take into account personal health considerations.

3. THIS IS NOT A DIAGNOSTIC TEST and cannot be used to confirm sucrose intolerance. Only a doctor can tell you if your symptoms are caused by CSID.

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